regular gas is sufficient, will premium gas hurt the car?

if the owners manual calls for regular, premium will only hurt your wallet

No, Premium will not hurt the car. If you live in an area where the temperature or your driving style create high Intake Air Temperatures, your car will pull a little bit of timing to prevent knock. In situations like these, Premium could actually make the car run better (more hp).

In most situations, 87 octane is all that is needed.

No, Premium will not hurt the car. If you live in an area where the temperature or your driving style create high Intake Air Temperatures, your car will pull a little bit of timing to prevent knock. In situations like these, Premium could actually make the car run better (more hp).

In most situations, 87 octane is all that is needed.

on the contraire.

i've asked an engineer friend of mine on another message board based on another thread here...he's an oil and gas guy in calgary...i'll just cut and paste his comment...i'm not sure but i'll take his word for it.

it can actually be bad to put high octane gas in a car that doesn't require it. a low compression engine will not generate the pressure and heat required to fully burn the high octane fuel. this can lead to extra deposits etc. on the cylinder and valves etc.

So what?
The CR of the DI engine is quite high. 11.3 IIRC.

and this motor uses the VVT capability to control cylinder filling and pressure, plus charge cooling EGR-type feedback. that and aluminum cylinder heads with better heat transfer support detonation-free 11.3:1 cr with 87 octane rating.
premium gas uses additives that slow the burn rate, since actual "octane" and lead are not used. these additional additives can leave extra deposits compared to lower octane-rating fuel. so, yes. but your wallet will feel the hurt more than the motor will.
rg

Ar~~~ I always thought the higher octane give me smooth acceleration... and it burn faster...

Please keep in mind that the higher the octane, the slower the rate of burn. Engine is designed for 87 octane. All the testing has been done using this criteria. I suggest that 87 octane is what should be used.

Actulally, in the owners manuals GM is recommending 89 octane for the DI engines, however 87 is acceptable. I specifically spoke with the service techs regarding this when I picked up my car. They suggested if I could afford the $0.10/gallon that I run the 89 in my DI.

Higher octane fuel actually burns slower and has a more controlled burn. As far as being bad for an engine that is totally untrue. Also note that most higher octane fuels claim to have more additives for cleaner burning and less deposits.

Actulally, in the owners manuals GM is recommending 89 octane for the DI engines, however 87 is acceptable...

Uh...actually, my owners manual (p. 5-5) recommends only "regular unleaded gasoline with a posted octane rating of 87 or higher." Here's what it sez:

"Gasoline Octane

[DI engine] If your vehicle has the 3.6L V6 engine (VIN Code V), use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, you might notice an audible knocking noise when you drive, commonly referred to as spark knock. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, the engine needs service.

[Non-DI engine] If your vehicle has the 3.6L V6 engine (VIN Code 7), use regular unleaded gasoline with a posted octane rating of 87 or higher. For best performance or trailer towing, you could choose to use middle grade 89 octane unleaded gasoline. If the octane rating is less than 87, you might notice an audible knocking noise when you drive, commonly referred to as spark knock If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, the engine needs service."

yeah.. the manual actually said 87 or higher.. so while 87 wont hurt, is 89 better.. since what im getting so far is that 89 wont hurt or does the same job as 87 for the car besides the wallet.. but no one gimme the ans for whether or not 89 does a better job..

~.20/gallon extra for 89... $4.199/g now, so you are at around $3 extra for each fill. the $ difference between 86 and 89 are small.. but i do agree that the gas price is ridiculously high

yeah.. the manual actually said 87 or higher.. so while 87 wont hurt, is 89 better.. since what im getting so far is that 89 wont hurt or does the same job as 87 for the car besides the wallet.. but no one gimme the ans for whether or not 89 does a better job..

~.20/gallon extra for 89... $4.199/g now, so you are at around $3 extra for each fill. the $ difference between 86 and 89 are small.. but i do agree that the gas price is ridiculously high

87 will hurt if your engine knocks under load while using it. then move up to 89. if your engine knocks while using premium (91 & higher) get it checked out because there is something wrong with it. that goes for both versions of the 3.6L VVT HF V6.
89 is better *only if* you need it to eliminate knocking under load with 87.
rg

Higher octane fuel actually burns slower and has a more controlled burn. As far as being bad for an engine that is totally untrue. Also note that most higher octane fuels claim to have more additives for cleaner burning and less deposits.

This is what I am under the impression of, and why I use 91....but others on here disagree and say I'm just wasting my money and potentially hurting my car. Is the cleaner burning gas with less deposits not worth my money? Or can the premium gas actually hurt my car?

I would also like to know the answer to the thread title.

This is what I am under the impression of, and why I use 91....but others on here disagree and say I'm just wasting my money and potentially hurting my car. Is the cleaner burning gas with less deposits not worth my money? Or can the premium gas actually hurt my car?

I would also like to know the answer to the thread title.

the answer is maybe (if the question was can it hurt the answer would be yes).
1. more deposits in some cases. sometimes this is offset by more detergent. 2. covering up problems that would be apparent with 87 or 89 octane. this is a secondary effect. so theoretically yes but in a practical sense the car will not know the difference. but you will ($$$).
rg

Will premium gas hurt your engine? No.

Can it hurt your engine? No.

Will it leave more deposits? No.

Is 87 "better" for it than 91 or 93? No.

...Is the cleaner burning gas with less deposits not worth my money?

You do not need higher-priced 89+ octane gasoline to get "cleaner burning gas with less deposits." All brands and grades of GM-recommended "Top Tier" gasoline already contain additives to reduce deposits and prevent valve-sticking http://www.toptiergas.com/deposit_control.html. If your engine does not ping or knock with "Top Tier" 87-octane regular gasoline, then 89+ octane is indeed a waste of your money.

...can the premium gas actually hurt my car?

Absolutely not, it will only hurt your wallet.

next question is:

i've been using 91 (premium) since my 1st fill and heard knocking sometimes.. and if now I switch to 87.. will there be sth wrong.

Uh...actually, my owners manual (p. 5-5) recommends only "regular unleaded gasoline with a posted octane rating of 87 or higher." Here's what it sez:

"Gasoline Octane

[DI engine] If your vehicle has the 3.6L V6 engine (VIN Code V), use regular unleaded gasoline with a posted octane rating of 87 or higher. If the octane rating is less than 87, you might notice an audible knocking noise when you drive, commonly referred to as spark knock. If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, the engine needs service.

[Non-DI engine] If your vehicle has the 3.6L V6 engine (VIN Code 7), use regular unleaded gasoline with a posted octane rating of 87 or higher. For best performance or trailer towing, you could choose to use middle grade 89 octane unleaded gasoline. If the octane rating is less than 87, you might notice an audible knocking noise when you drive, commonly referred to as spark knock If this occurs, use a gasoline rated at 87 octane or higher as soon as possible. If you are using gasoline rated at 87 octane or higher and you hear heavy knocking, the engine needs service."


Since the DI vs non DI is not declared in the owners manual. I asked the shop to verify which Vin Code applied since I had both digits in my code and was not aware which one was applicable to the engine code. They indicated that the DI engine was a code 7....which recommend the 89 for best performance. I am willing to to acknowledge that I may have been misinformed but the given this was a DI engine it seemed logical to me that the higher performance engine would do best on a higher octane fuel. There is however clearly a recomendation that one engine whether DI or VVT would perform better on 89.

Since the DI vs non DI is not declared in the owners manual. I asked the shop to verify which Vin Code applied since I had both digits in my code and was not aware which one was applicable to the engine code. They indicated that the DI engine was a code 7....which recommend the 89 for best performance. I am willing to to acknowledge that I may have been misinformed but the given this was a DI engine it seemed logical to me that the higher performance engine would do best on a higher octane fuel. There is however clearly a recomendation that one engine whether DI or VVT would perform better on 89.

oops for the dealer. the DI version is V, PI is 7 (8th digit of the VIN). to make sure check your vehicle sticker, or look under the spare tire cover: LLT is DI, LY7 is PI. again it will "perform better" with 89 only if 89 is required to eliminate detonation under load. and they have made it quite clear that this detonation is rare and depends on particular situations. knocking under other conditions, especially if using premium, is an indication of a problem with the engine.
rg

There is another article on this same subject which is active which adresses this very subject. It is an excellent source of information and is written by "Southern". I suggest that you read it. According the the manual it states that regular is the recommended fuel for this engine, not 89 or 91. It does make the exception that if the car is towing a trailer and the engine is pinging you can move up to 89 octane.
Basically using anything other than regular is just of wast of money, and could damage the engine in the long run. If you go into detail in the manual about fuels, it states the using fuel with MMt which is used in many higher octanes are recommended to be avoided (page 5-6 in the users manual). I think that if you do your research youo will see that using anything other than regular is just a waste of money which could turn around and bite you in the long run.

C'mon, folks!

GM recommends "Top Tier" gasolines, 87-octane or higher. GM helped develop and set the standards for "Top Tier" gasolines. All brands and grades of "Top Tier" gasolines DO contain additives to minimize deposits and DO NOT contain metallic additives, including methylcyclopentadienyl manganese tricarbonyl (MMT) or anything else that's known to harm your CTS engine.

It's really quite simple. GM-recommended "TOP TIER" gasolines, 87-octane or higher - i.e., 87, 89, 91, 93-octane, will NOT damage your CTS engine.

C'mon, folks!

GM recommends "Top Tier" gasoline's, 87-octane or higher. GM helped develop and set the standards for "Top Tier" gasoline's. All brands and grades of "Top Tier" gasoline's DO contain additives to minimize deposits and DO NOT contain metallic additives, including methylcyclopentadienyl manganese tricarbonyl (MMT) or anything else that's known to harm your CTS engine.

It's really quite simple. GM-recommended "TOP TIER" gasoline's, 87-octane or higher - i.e., 87, 89, 91, 93-octane, will NOT DAMAGE your CTS engine.


I agree, octane is not the issue. Quality of the fuel is, and they are not all the same. So you price shoppers that go to the unbranded stations beware.

much of this discussion is getting off topic. there are other threads that address pros and cons of the various grades and what the manual tries to explain.
I believe the OP has been answered - stick to Top Tier brands (I would also add name brands too but that is IMHO only) and you will not have to worry about premium fuel causing damage to the engine.
rg

I agree, octane is not the issue. Quality of the fuel is, and they are not all the same. So you price shoppers that go to the unbranded stations beware.

Allow me to field this one. The "unbranded" stations sell gasoline made in the EXACT same refineries as branded outlets, and to the same specifications. Ever see a "Quick Stop" refinery? I didn't think so.

GM has also stated many times that the DI engine was designed to run on regular, not the higher octane fuel. That is what gives it one of it's many advantages over the competition, which does have to use a higher octane fuel to perform as designed. Why waste the money?

Allow me to field this one. The "unbranded" stations sell gasoline made in the EXACT same refineries as branded outlets, and to the same specifications. Ever see a "Quick Stop" refinery? I didn't think so.


Do you think the truck that pulls into the Quick Stop came from the Refinery?
No, he did not.
He came from the fuel distribution center.
The major brands often have their own distribution center (And refineries) , and sometimes really large chains, like Quick trip, may have their own distribution centers..

In any event, the gasolines sent to the distribution center are virtually identical at this point.

However, it is just fuel stock at this point.
It is not Quick Stop OR Shell OR Chevron......
It is just fuel stock.

Now comes the part that separates the men from the boys.....At the Distribution center is where many of the additives, especially the detergents, are blended in to the fuel stock.
And guess what? Shell put in about twice as much detergent as Quick Stop.
So, it becomes a different gasoline.
And it could be from the same distribution center.
They both are rated 97 poctane.
They both will pass various state req for Sediment and flash point,etc........
But continued use of Quick stop, in some engines , will result in a build up of deposits.

BMW and GM noticed this a couple of years ago.
They were having problems with their high performance engines,in warranty. It was traceable to the build up of deposits
They got together with Chevron and some others and formed a consortium called Top Tier Gas.
They defined levels of various detergents by defining what level of deposits were acceptable.
They developed stanadrd tests. and invited all the brands to participate.
They do charge to run the tests, but It is a non profit group that certifies gasoline quality for use in their engines..... And BTW the testing is done by GM.
Other manufacturers got in on it and now there are quite a few automobile mnufacturers (but not all) that recommend Top Tier Gas.
And there are an ever increasing number of gasoline brands that are adding the additional additives and paying to be tested and certified.

You can find out about them here:

http://www.toptiergas.com/

They even show the actual tests on this site.

I run Top Tier in My VQ engined Nissan.
I ran Top Tier in my BMW.
Most certainly, I would never run anything other than Top Tier in my DI engine.

Yes, there IS a difference in gasolines.

Allow me to field this one. The "unbranded" stations sell gasoline made in the EXACT same refineries as branded outlets, and to the same specifications. Ever see a "Quick Stop" refinery? I didn't think so.

I guess what you are saying is that all gas is the same and that makes them all Top Tier. I don't think so.

At a terminal the fuel is blended for each purchaser according to their specs. Reason why the unbranded can sell cheaper is because the gas is generally a lesser quality and cost less.

hmm... I only do Chevron's top tier since mi 1st fill.. running pretty well right now. occasionally I do shell if chevron is too far away

I use only Shell gasoline but they are the only name on the top tier list that you will find in NJ.

Read Southern's post, number 27 above, that's good stuff.

I'm not sure we know what we are pumping when we get gas. In my travels I can tell you that the only place along the east coast that gives my car a pain is South Carolina. Next fill up north or south of there makes it all O.K. ???:bonkers:

This is all fascinating, but it still doesn't change two facts:

1- Premium fuel will not hurt your engine

2- If you run the car in an extreme environment where temperatures will be high (underhood and intake air) then the car will run better on Premium since it's not pulling timing to prevent detonation.

The question was "Will Premium gas hurt the CTS?" The answer is no. My CTS-V manual says "87 or higher" and it's never seen a drop of anything below 93. When I had the intake manifold off recently at 40,000 miles I inspected the valves and they look fantastic- no mysterious "deposits" from Premium.

I guess what you are saying is that all gas is the same and that makes them all Top Tier. I don't think so.

At a terminal the fuel is blended for each purchaser according to their specs. Reason why the unbranded can sell cheaper is because the gas is generally a lesser quality and cost less.

No, I certainly am not saying that all gasoline is the same. HOWEVER, all gasoline is refined at the same facility and even when blended to spec must conform to certain minimum standards, all of which are formulated to meet the demands of modern engines.

I'm still under the belief that there is one tank under the gas station:wacky:

No, I certainly am not saying that all gasoline is the same. HOWEVER, all gasoline is refined at the same facility and even when blended to spec must conform to certain minimum standards, all of which are formulated to meet the demands of modern engines.

RightTurn, where gasoline is refined and the specs for reformulated gasoline are irrelevant here. We're talking about finished brand product, including all additives, at the pump where Cadillac's fuel standard for CTS V-6 engines is HIGHER than your generic "certain minimum standards, all of which are formulated to meet the demands of modern engines."

Six of the world's top automakers, BMW, General Motors, Honda, Toyota, Volkswagen and Audi recognize that the current EPA minimum detergent requirements do not go far enough to ensure optimal engine performance.

I for one believe that the minimum standards are not good enough. I have seen first hand the negative effects gasoline could have on engine performance, (plugged injectors, carbon build up on back side on intake valves, ect). Not to mention that engine design change continuously, and the demands on the todays engine increase. So last years standards may not be good enough.
Most owners never notice the negative effects because they are slow coming and by the time they become severe they have higher mileage which then becomes the reason in the owner eye. Use of a high quality fuel and also high quality oil goes a long way to longevity and performance on an engine.

I looked at the top tier and I was surprised Arco wasn't on there. Guess I better stop feuling up there :D

Can anyone tell me were Turkey Hill Minit Markets is? Has anyone confirnmed that this is a good web site?

I am in agreement with the masses that say it's OK to burn higher octane. If it wasn't wouldn't the manual say 87 only instead of 87 or Higher???

I could run 87 in my V. Since these cars are equiped with a knock sensor and computer controlled it will retard the timing to prevent knock but I really like the power so I only only run 91 or higher (91 is the standard "premium in CA, another sucked part about california).

I would retune the car and run a higher octane if it were readily available.

If the staements that some of the members were true then please explain to me why they run 100+ in Europe and japan???

Auto manufacturers have made great progress to make a car run on a lower octane and they will allow you to run it but it doesn't mean it's the best.

This what I believe to be true from what I have read and seen but don't trust me or any other poster, go out and find out for yourself.

Ronster, what kind of engineer was your friend - Civil?, Electrical?, Software?

Turkey Hill is in PA for sure.......

As to the 100+ in Europe and japan......
it's all in how you derive the number.
There is a number called Reseach Octane Number (RON)......europe (And I would assume Japan) uses this number.
There is also a number called Motor Octane Number......europe ignores this number.

We don't.
We add RON and MON and divide by two......its often just printed as R+M/2
It comes out lower........

I'm still under the belief that there is one tank under the gas station:wacky:

oh yeah.. how do they fill the tank in the gas station..

i usually see only one gas carrier truck filling the tank in the gas station..
you dont see 3 different gas trucks filling tanks separately..
but well.. on koz the truck can have different sections to hold different types of gases.. but well. what's the different... so in simple.. the higher tier the gas is, the clearer it is?

The tanker only needs two different grades, low and high octane; the pumps either pump low, high or blend. You don't think Sunoco has tanks for all the grades/midgrades they offer. And although improprieties can occur, octane checks and delivery checks are carried out randomly (at the pump).

I think its important to use a tier one gasoline more so than high test over regular..

Shell, Chevron and a few other brands are considered tier one brands...

Good luck and regular fuel is fine. Just try and use tier one brands..

JMO

JB

http://www.aa1car.com/library/bad_gas2.htm

Bad Gasoline Update, January 2006
By Larry Carley c2006

Gasoline quality is an issue few people think about. When hurricane Katrina hit in the summer of 2005, gasoline prices soared. Everyone was scrambling to buy the cheapest gas they could find, and the sales volume of premium and mid-range gasoline dropped. They said there was a serious fuel shortage, so refiners who were normally required to make reformulated gasoline (lower emissions) were temporarily allowed to cut some corners so they could produce more gallons of gasoline from each barrel of crude oil. Consequently, there was an unpublicized drop in both fuel quality and octane rating during this period. We also suspect that some oil companies (but not all) also used this opportunity to cut back their use of detergents and deposit control additives in their gasoline.

When the crisis had passed, gasoline prices came back down, the panic passed, and the sales volume of premium and mid-range gasolines went back up. Since then, gas prices have climbed back up to to over $3 a gallon -- but there is no hurricane to blame this time.

As far as we know, a couple of months of over-priced, sub-par gasoline during the so-called Katrina "crisis" did not cause many noticeable problems with engine performance. Thanks to the knock sensor, most engines (even those with higher compression ratios) can usually tolerate some deviation in the octane rating of the fuel -- at least for short periods of time.

But lately, it seems we've been hearing more complaints about driveability issues that are typically caused by a build-up of varnish deposits in the fuel injectors and throttle body, and carbon deposits on the intake valves and in combustion chambers. These problems include engine knock after cold start or when the engine is working hard under load, hesitation problems when accelerating, rough idle, poor fuel economy and even misfiring (which often turns on the Malfunction Indicator Lamp).

We have not found any recent studies by the government or anybody else that addresses the issue of fuel quality or whether the level of detergent and deposit control additives in gasoline is sufficient to keep today's engines clean. But we suspect that if such a study were undertaken during the aftermath of hurricane Katrina, it would have revealed widespread problems with inadequate levels of these necessary additives in some gasolines.

GASOLINE DEPOSIT FORMATION

When deposit control additives are not adequate in gasoline, harmful deposits can build up inside the engine:

* Fuel varnish deposits that form inside the injectors restrict fuel delivery and cause the engine to run lean. This may cause lean misfire, rough idle, hesitation, poor fuel economy and increased HC emissions. A lean fuel mixture also increases the risk of detonation and preignition. These deposits tend to form during the heat soak period that occurs after the engine is shut off. The shorter the trips and the more frequent the drive cycles, the faster these deposits buildup.

* Deposits that form in the throttle body can reduce airflow through the idle bypass circuit affecting idle quality and smoothness. These deposits are formed by fuel vapors that rise up through the intake manifold.

Intake valve deposits from gasoline that does not contain enough detergent


* Deposits that form on the intake valves can restrict airflow through the intake ports, causing a loss of high speed power. The deposits can also act like a sponge and momentarily soak up fuel spray from the injectors. This disrupts the mixing of air and fuel causing a lean fuel condition, hesitation and reduced performance. Deposits can also cause valve sticking and valve burning. Intake valve deposits are formed by normal combustion byproducts, but may build up more rapidly if the valve guides or seals are worn and the engine is sucking oil down the guides.

* Deposits that form inside the combustion chamber and on top of the pistons increases the compression ratio of the engine and the octane requirements of the fuel. Too much compression can cause spark knock (detonation) if the fuel's octane rating isn't high enough. Over time, detonation can damage the head gasket, piston rings and rod bearings if it is not controlled. The knock sensor will detect detonation and tell the PCM to retard spark timing. This will take care of the knock, but retarded timing also increases fuel consumption and emissions.

A build up of carbon deposits inside the combustion chamber also increases the risk of hot spots forming that may cause engine-damaging preignition. The hot spot ignites the fuel before the spark plug fires, causing a sharp rise in combustion pressure. Under extreme conditions (high rpm and load), preignition can burn a hole right through the top of a piston!

A condition known as Combustion Chamber Deposit Interference (CCDI) can also occur when the carbon deposits are so thick the deposits on the piston and head make physical contact. This area, known as the Squish Area (piston to top of chamber), has a clearance that is about as thick as a paper clip. This can cause a loud, metallic banging sound when a cold engine is first started. The deposits are soft and will gradually flake off. But the flakes may lodge between the valves and seats causing a loss of compression, misfiring and rough running when the engine is cold (a condition called Combustion Chamber Deposit Flaking or CCDF).

KEEPING FUEL INJECTORS AND COMBUSTION CHAMBERS CLEAN

The formation of harmful deposits can be controlled by adding detergent-dispersants to gasoline, the most common of which is polybutene succinimide. Used with a petroleum carrier oil, detergent-dispersants help keep the intake manifold and ports clean. These chemicals are more effective than the carburetor detergents that were once used in gasoline, but they must be used at concentrations that are three to five times higher than the older carburetor detergents.

Deposit control additives such as polybutene amine (PBA) were introduced in 1970 to help keep injectors and intake valves clean. The only drawback with PBA is that too much of it can increase combustion chamber deposits. Polyether amine (PEA), by comparison, cleans fuel injectors and valves, and does not increase combustion chamber deposits. In fact, it helps remove accumulated deposits inside the combustion chamber to reduce the risk of spark knock.

In 1995, the U.S. Environmental Protection Agency set minimum standards for additives in gasoline to prevent the formation of deposits in fuel injectors. Gasoline refiners had to certify their additive packages met these standards, but some experts now say the original standards were set too low and do not provide adequate protection with some fuels and engines. The minimum EPA required level is referred to as the "Lowest Additive Concentration" (LAC), and is typically found in the cheapest priced gasoline.

TOP TIER GASOLINE

At the other end of the fuel quality spectrum are "Top Tier" gasolines. These fuels are recognized by the vehicle manufacturers as having the most effective additives and in the highest concentrations. Gasoline retailers must meet the high Top Tier standards with all their grades of gasoline (not just premium) to be designed as a Top Tier supplier. In addition, all the gasoline outlets carrying the brand of approved gasoline must also meet the same standards. Gasoline retailers who are currently on the Top Tier list include Chevron, Chevron-Canada (B.C. only), Texaco (Chevron supplied only), Conoco, Entec Stations, Kwik Trip/Kwik Star, MFA Oil Company, Phillips, QuikTrip, Shell, The Somerset Refinery and 76.



POLICING GASOLINE QUALITY

Unfortunately, fuel quality isn't something that is easily policed. Many states have programs in place to monitor fuel quality on either an ongoing basis or "incident specific" basis. Most are run by the state's Department of Weights and Measures. Even so, the focus of most of these programs is to make sure consumers aren't being cheated at the pump and get the full gallon they pay for. Some programs also check fuels to make sure they do not contain too much alcohol. The specific density of gasoline can be field tested to determine its volatility and alcohol content. But testing octane and the amount and type of additives in the fuel requires expensive laboratory testing. So this type of quality testing is rarely done.

According to one leading gasoline retailer (who sells a Tier One fuel, by the way), many gasoline marketers have reduced the concentration of fuel additives in their fuel up to 50% in recent years!

Most gasoline refiners don't want to sell the public bad gas because they obviously want repeat customers. Even so, they also know that deposit formation is a gradual thing that occurs over time. So if they cut back on the additive package to save a few cents per gallon, nobody is the wiser -- and least not right away.

The problem occurs when people buy the cheapest LAC gas they can find every time they fill their tank. The low level of additives (or low quality additives) in the fuel will not be adequate to keep their engine clean, and sooner or later they'll start to experience driveability problems.

Worse yet, if a bad batch of fuel leaves a refinery and ends up in people's vehicles, it can cause even more serious problems. There have been instances where too much residual sulfur in a bad batch of gasoline has caused a rash of fuel pump failures.

Immediate driveability problems may also occur if the fuel is contaminated with water, contains too much alcohol or the wrong type of alcohol (methanol instead of ethanol). Alcohol is a great octane booster, but for ordinary gasoline the amount of ethanol should not exceed 10% (or 5% for methanol). The only exception here is G85 fuel for "flex-fuel" vehicles that is 85% ethanol and 15% gasoline. G85 contains less energy per gallon than gasoline and runs leaner, so the vehicle must have a special fuel sensor so the PCM can compensate for the alcohol to maintain the proper air/fuel ratio.

GETTING RID OF FUEL DEPOSITS

When a vehicle is experiencing deposit-related driveability, performance or emissions problems, the deposits obviously have to go. The troublesome deposits can be removed a variety of ways. One cost-effective solution to deposit-related driveability issues is to simply add a can of fuel system cleaner to the fuel tank. The cleaner will slowly remove the deposits while the vehicle is driven. The only drawback with this approach is that it takes time -- maybe one or two tankfulls with the additive to make a noticeable difference. That may be too long for some people.

For those who want a more immediate fix, the cure usually consists of cleaning the throttle body with an aerosol cleaner, flushing the injectors with a concentrated solvent or cleaning product, and/or feeding an intake system cleaner of some type into the engine while it is running to clean the intake ports, valves and combustion chamber.

If injectors fail to respond to on-car cleaning, they can be removed for more thorough off-car cleaning on special equipment -- or replaced if they are clogged and can't be cleaned.

For heavy carbon deposits inside the combustion chamber, a top cleaner product may be added to the engine and allowed to soak for 15 to 20 minutes to loosen the deposits. An oil change afterwards is recommended because some of the cleaner will end up in the crankcase.

For extremely stubborn intake valve and combustion chamber deposits, blasting the valves through the spark plug holes or intake ports with a soft media such as walnut shells is an easier fix than pulling and disassembling the cylinder head for hand cleaning.

To prevent the formation of new deposits once the engine has been cleaned, you should recommend using a top tier gasoline or adding a bottle of fuel system cleaner periodically to the fuel tank (say every four or five fill-ups or when changing the oil every 3000 miles).

FUEL CLEANING ADDITIVES NOT THE SAME

One very important point to keep in mind about aftermarket fuel system cleaners that are added to the gas tank is that they use different chemistries to achieve different results. As we said earlier, some chemicals such as PBA can clean injectors and valves but may actually increase combustion chamber deposits. Other chemicals such as PEA can clean the entire fuel system as well as the combustion chambers.

For dirty fuel systems, you should use a product that is concentrated enough to provide some real cleaning action. But for maintenance, you only need a product that keeps deposits from forming.

One new fuel system cleaning product that has been recently introduced does something no other product does: it actually cleans and protects the contacts on fuel gauge sending units. The contacts on the sending unit are typically plated with silver-palladium to resist corrosion. But over time, residual sulfur in gasoline can corrode the contacts causing the gauge to rear erratically or not at all. Replacing the sending unit is an expensive job because you have to drop the fuel tank, so a more affordable alternative is to simply add a bottle of this product to the tank and let it take care of the corrosion.

For CTSV Rob.Turkey Hill is a chain of mini markets. Home base is Columbia, Pa. On the banks of the Susquehanna river. Started out as a dairy, milk, ice cream etc. Now they all have gas pumps and cometetive pricing.

What about the summer and winter mixes? Are they both OK? Just kiddin'... :)

what if i buy a lotto ticket with my gas? will that hurt my engine?

Do not attempt to fill your tank with quick pick lotto tickets- multiple On-Line research studies have proven that this will damage your engine. Use the scratch-off variety and you'll be fine.

:lol:

Seriously guys, I think this has been covered pretty well: Use Top Tier gas if available, and always use 87 or higher. Sometimes the simple answer in the owner's manual is the correct one.

TONY!!! I'm with you, bud. You are preaching to the choir!

I have a different question.....Are there any advantages to putting 100 Octane Racing Fuel in this car just for shits and giggles?! I would never consider filling up with 100 more than one time a year.


I remember a few years ago when gas wasn't as high as me on 4/20, me & my bro filled up his 2001 330ci with 100 Octane fuel on the way to San Diego and the car was just running awesome and effortlessly. Since it's designed for 87 Octane, does it have the correct sensors to take advantage of 100 Octane? Just curious.

http://www.motortrend.com/features/performance/112_0606_sf_high_octane_fuel/

Nice article. :thumbsup:

Some good info in there.
Couple of points....
don't try to carry too much of this info to your CTS....
Racing engines are not adaptive engines like your CTS engine is.
Adaptive engines have knock sensors and computer control that take the results of the sensors and advance or retard the timing as appropriate.
Racing engines do not have either knock sensors or computers.

The difference?
You can run regular OR premium in your car and it wont hurt it.

If you try to run low octane gas in a racing engine, it would be destroyed.

Oh yes, MTBE, as mentioned in the article, is not used "extensively" as stated.
In fact it is illegal in most parts of the US and is being phased out everywhere else.
Keep in mind that this article is about 2 years old.


These guys credentials are flawless. Union 76 was the only racing gas allowed when I was active in Nascar. It is Sunoco nowadays.

southern are you a former Nascar professional racer? it will be so cool if you are!

I raced Nascar Grand National Modifieds when it was the precursor to the Winston Cup.

I ran on the Deep South Circuit in the 60s. Running Montgomery (home track), Birmingham, Phoenix City and Panama City, etc.
Raced against Bobby and Donnie Allison, Red Farmer and other greats of the era.
As to Greats....... I wasn't.
I did run in the top three in Montgomery in 63 and made money at the other tracks (Very little money. We ran for $500 purses....)
Bobbie is still a friend of mine although he had an accident late in his career and has never been quite the same.
Red was probably the best at those tracks, but couldn't handle the superspeedway. So when Bobbie and Donnie moved upi to the Winston cup, Red stayed on the 1/2 mile paved tracks. He STILL races occasionally.

In the 90s I became part owner of a Super Modified and Bush Series car with Tim Maloney of Maloney Racing, and we did well.
Jimmy Spencer was the top driver of this crew and he won the National Super Modified Title before moving on to the Winston Cup.
Jimmy is out of Nascar now, but he had an "interesting" career.
He was a hell of a driver in his prime.
Maloney Racing ceased operations in 2001.

I also served on the Pit Crew of an entry in the Toyota Series during the 90s, for one year.
The Pit crew in the Toyota series did 99% of their work before the race. If you had to do something in the race, you had lost.

Right now I have no connection to racing at all, although I still have friends in the game.
I know some of the guys at Michael Waltrips racing garage.
Harry White for instance, has one foot in retirement, but he and I go back maybe 40 years and he is their chief machinist.

I enjoyed racing, but except for a brief period in the 60s, it was a hobby for me.

Hoping this thread is pretty much done I'd like to say Southern that's a cool history. there was a lot of regional activity in the 60s and into the 70s. where I grew up I hung around short tracks, mainly the ones where my cousins raced. I did my racing in the street. if you know of Rich Bickle he's from my hometown and I believe I bought a muncie tranny from a relative of his. some of my family is friends with Kenseths and there was talk that we could be (very remotely) related. also I like watching the speed ch. show 'back in the day' seeing the races from late 60s and early 70s, the really great gearhead days. in fact used to watch car and track or whatever it was called, where they get the original race footage.
*/reminiscing OFF/*
rg