: 2.0T which octane gas is best, performance vs. cost



mbk2010
05-24-13, 11:54 PM
Just picked up my ATS on Tuesday and it's time for a fill up.
I know they say 91 octane is 'recommended' but not 'required' for the 2.0T.
Would love to get some feedback, thinking maybe 89 would be a good compromise,
as the dealers really seem to gouge you for 91 these days.

desmar
05-25-13, 12:05 AM
Hi mbk2010
I know it recommends 91 Oct., I'm of the belief to follow manufacturers recommendations, they design the vehicle to operate at certain parameters & tolerances, it will pay out in the long haul. It's up to you whether you want pay now or later, the difference is how much.
It will use the 91 Oct.

donavo
05-25-13, 05:54 AM
It's seriously like a 1.60 dollar difference Per fill up .... You can't be that cheap...

mbk2010
05-25-13, 09:54 AM
As of this morning it's 3.50 average for regular and 3.89 for premium in MA. So while I'm hardly cheap, it does add up !

Stevo Supremo
05-25-13, 10:14 AM
It's seriously like a 1.60 dollar difference Per fill up .... You can't be that cheap...

lol ya dont be cheap :P I had to put premium in a cobalt or the bugger knocked. That being said, I have no issue putting premo in a brand new Cadillac lol

Hoosier Daddy
05-25-13, 12:04 PM
Just picked up my ATS on Tuesday and it's time for a fill up.
I know they say 91 octane is 'recommended' but not 'required' for the 2.0T.
Would love to get some feedback, thinking maybe 89 would be a good compromise,
as the dealers really seem to gouge you for 91 these days.
This is almost definitely something you want to test for yourself.

Try a tank of each and drive as you normally will. If possible, have a 2nd party choose the grade each time and not tell you until all tests are done. Make notes about anything you might forget.

I think you are smart to find out what you need. I don't think spending extra money for no return is ever a good idea unless you are already financially set for life and don't care. Its quite possible you will want 91 octane after the tests but its also possible you can't tell the difference where and how you drive.

thebigjimsho
05-25-13, 08:11 PM
As of this morning it's 3.50 average for regular and 3.89 for premium in MA. So while I'm hardly cheap, it does add up !

Doesn't add up enough. Don't give MA residents a bad name now...

Bertha D Blues
05-25-13, 09:25 PM
Gees, I paid $4.28 for 91 octane here in Nebraska today and AV gas is $6.50.

SLA
05-25-13, 10:11 PM
91 is recommended. Fuel mileage will most likely be effected by using anything less.

I know for a fact power is less on 87, thanks to that tank of craptastic gas the dealer gave us for the CUE update. My butt dyno don't lie.

You can pay a bit more and put 91+ in it and keep the power and fuel mileage or you can put a lesser grade in it and have less power and visit the pump more frequently.

Lorne
05-26-13, 08:13 PM
I figure that the cost difference between using 87 and 91 would be no more than $200 a year. I think it's worth it to use 91. Of course, it depends how much you drive.

YoshiFD3S
05-26-13, 08:41 PM
....you buy a Cadillac but go cheap-skate on the gas...

Contradiction, anyone?

73JPS
05-27-13, 01:53 PM
I figure that the cost difference between using 87 and 91 would be no more than $200 a year. I think it's worth it to use 91. Of course, it depends how much you drive.

It's about 17 cents a liter more, and at 25K km a year for me, that works out to about $450 more per year; I do use the 94 Octane (I figure after I get a hose full of the 87 the person before me put in their car, I probably end up with 91 Octane in my tank by the time all is said and done), and besides it's only 2 cents a liter more than the 91.

Siren05
05-27-13, 02:00 PM
It's about 17 cents a liter more, and at 25K km a year for me, that works out to about $450 more per year; I do use the 94 Octane (I figure after I get a hose full of the 87 the person before me put in their car, I probably end up with 91 Octane in my tank by the time all is said and done), and besides it's only 2 cents a liter more than the 91.

94 is all I use. Reduce knock dramatically. And allows tuners to lean the car out up top

donavo
05-27-13, 02:04 PM
damit i wish i had 94 available....

mbk2010
05-27-13, 07:43 PM
OK OK the masses have spoken and I have listened, 91 only for me :yup:

Hohums
05-28-13, 08:31 AM
Filling up in Toronto ON today:

87 oct - $1.30 per L
91 oct - $1.50 per L

Costs me an extra $8-10 per fill for 91oct over regular ... probably around $500 more over the course of a year.

Then again I used to live in the UK so nobody in either the US or Canada can legitimately complain about gas prices, haha! Rougly converting it, regular 87 gas in the UK is around $9.20 per gallon right now. Ouch.

flycaster
05-28-13, 12:36 PM
Although I have yet to use 87 in the ATS, over the last 11 years I have had the opportunity to use 87 in my BMWs (325 and Z4). I have never filled the cars totally with 87, but rather used it when the tank was half filled with 93 (or 91). I have never had a knock or really noticed any difference in performance (not that I have tracked the cars). I will probably start to use some 87 (in the same manner as I did with the BMWs) after I feel the car is fully broken in, and I don't expect to have any knock problems. It is my understanding that the ATS' engine computer should adjust (as they did for my BMWs) mixtures and timing so that there will be no knocking. Well, we'll soon see...

Lorne
05-28-13, 07:04 PM
Filling up in Toronto ON today:

87 oct - $1.30 per L
91 oct - $1.50 per L




I don't know where you're buying your gas, but you're getting ripped off on the 91! Checking Gas Buddy, Esso at Yonge and Steeles 87 is 127.9 and 91 is 143.9 Average prices for the area seems to be 128.1 for 87 and between 143.9 and 144.9 for 91.

73JPS
05-28-13, 11:48 PM
I don't know where you're buying your gas, but you're getting ripped off on the 91! Checking Gas Buddy, Esso at Yonge and Steeles 87 is 127.9 and 91 is 143.9 Average prices for the area seems to be 128.1 for 87 and between 143.9 and 144.9 for 91.

This looks about right: roughly 16-18 cents per liter more for 91 or 94 over 87... for US folks that's (very) roughly 65 cents a gallon.

Siren05
05-29-13, 10:48 AM
Although I have yet to use 87 in the ATS, over the last 11 years I have had the opportunity to use 87 in my BMWs (325 and Z4). I have never filled the cars totally with 87, but rather used it when the tank was half filled with 93 (or 91). I have never had a knock or really noticed any difference in performance (not that I have tracked the cars). I will probably start to use some 87 (in the same manner as I did with the BMWs) after I feel the car is fully broken in, and I don't expect to have any knock problems. It is my understanding that the ATS' engine computer should adjust (as they did for my BMWs) mixtures and timing so that there will be no knocking. Well, we'll soon see...

Your bmws were NA not boosted. If your PCM detects knock which it will on boosted cars under heavy load using 87 octane.
It will adjust power accordingly:) downwards
. Your German cars are 6 cylinder naturally aspirated engines that cannot take advantage and adjust anyway. :)

Yplus
05-29-13, 02:25 PM
If you're on the northeast, the best deal is usually Sunoco 91. Since they offer "Ultra" 93 (remember when it was Ultra 94 ;) ) as "premium" the 91 sits between premium and mid-grade and is a few cents cheaper than other places' "premium" that only offer 87/89/93. You absolutely do not need anything more than 91 since you cannot get it in California if you wanted to and therefore cars sold in the US that need premium must be designed to run optimally on 91. If you tune, well, that's a different story.

You'll get less mileage with lower octane in modern computerized engines (they need to run richer or retard timing to prevent knock, both make less power relative to the optimum timing/AF ratio), so when you "save" money on mid-grade fuel, you burn more gas, eating away at the savings (and creating more CO2, BTW).

Lorne
05-29-13, 07:02 PM
If you're on the northeast, the best deal is usually Sunoco 91.

However... The owners manual recommends only using Top Tier gas, and Sunoco is not on the list of Top Tier retailers!

Lorne
05-30-13, 05:17 PM
This looks about right: roughly 16-18 cents per liter more for 91 or 94 over 87... for US folks that's (very) roughly 65 cents a gallon.

Yet in Western New York and Northwest Pennsylvania, I've found they charge an extra 25-35 cents per gallon more for 91 over 87. Maybe the difference has to do with ethanol? All gas in the US has ethanol; in Ontario, all 87 from the major retailers has ethanol, but 91 does not have ethanol at Esso and Shell. Could part of the price difference between Canada and the US for premium be because 91 is ethanol-free in Canada?

stevenzoz
06-02-13, 02:51 PM
My salesman INSISTED I put regular in the car. When taking delivery I asked if they could put premium. He said, "No, this car is meant to run on regular." I was annoyed after I read the manual and it said premium is best to avoid the knocking noise, etc with using regular.

Hoosier Daddy
06-02-13, 03:39 PM
My salesman INSISTED I put regular in the car. When taking delivery I asked if they could put premium. He said, "No, this car is meant to run on regular." I was annoyed after I read the manual and it said premium is best to avoid the knocking noise, etc with using regular.
Never believe a salesperson. On the plus side, it made no difference on the first tank if you stayed anywhere near the break in procedure in the owner's manual.

M5eater
06-03-13, 09:09 AM
My salesman INSISTED I put regular in the car. When taking delivery I asked if they could put premium. He said, "No, this car is meant to run on regular." I was annoyed after I read the manual and it said premium is best to avoid the knocking noise, etc with using regular.

Salesmen are there to sell to a person, they're not there to know every single tiddly fact on a car. They need to figure out what your needs and wants are before they try selling you a car, or they just tell you what you want to hear. Being able to run on regular in a premium car is a 'plus' to some people.




I don't know where you're buying your gas, but you're getting ripped off on the 91! Checking Gas Buddy, Esso at Yonge and Steeles 87 is 127.9 and 91 is 143.9 Average prices for the area seems to be 128.1 for 87 and between 143.9 and 144.9 for 91.


He pops into Suffolk, UK to top-off in the morning.

The only people that have a legitimate reason to choose a lower octane don't get their gas in the US. We have some of the most affordable gas in the world. Please take advantge of it while you still can. There are much better ways to save < $200 annually. At the very least you want to limit the chances of carbon buildup as much as possible.

Stevo Supremo
06-03-13, 11:10 AM
Never believe a salesperson. On the plus side, it made no difference on the first tank if you stayed anywhere near the break in procedure in the owner's manual.

see whats sad here is a few bad apples ruin the batch. My father and brother are both car salesmen, my bro sells Chevrolet and my Dad sells Cadillac/Chevrolet. They're both car nuts and know just as much/more as most of the people here, and they're dead honest with customers. It really sucks when you get a bunch of dip shit salespeople that know NOTHING about cars and have NO passion for cars that ruin it for the rest of them.

I wanted to slap the sales man who told me they never made a turbo cobalt, such ignorance, I dont get why you sell something you have no passion for.

Hoosier Daddy
06-03-13, 11:47 AM
I dont get why you sell something you have no passion for.
I'm gonna go out on a limb and guess its the best job they could get.

Or maybe:


http://www.youtube.com/watch?v=O48Cr5vm6Yg#t=73.8

donavo
06-03-13, 01:08 PM
can anyone go ahead and explain to me how the whole mothball thing works? from a couple of older co workers, i heard that they used to drop a mothball in their gas tank and get way higher octane. doesnt this make the fuel dirty? and is that an option for people with low octane gas with these cars? id imagine it would ruin the engine.

Stevo Supremo
06-04-13, 11:44 AM
can anyone go ahead and explain to me how the whole mothball thing works? from a couple of older co workers, i heard that they used to drop a mothball in their gas tank and get way higher octane. doesnt this make the fuel dirty? and is that an option for people with low octane gas with these cars? id imagine it would ruin the engine.

Are you the same guy that put sand in his audi's engine in the hopes it would port and clean it?!

donavo
06-04-13, 12:38 PM
Are you the same guy that put sand in his audi's engine in the hopes it would port and clean it?!

no. i havent heard of anything like that cleaning an engine.

Stevo Supremo
06-04-13, 01:57 PM
ahem

http://www.audiforums.com/forum/off-topic-5/hey-guys-please-help-my-mods-gone-wrong-80267/

donavo
06-04-13, 02:01 PM
ahem

http://www.audiforums.com/forum/off-topic-5/hey-guys-please-help-my-mods-gone-wrong-80267/

yeah thats not me. back to the mothball. im sure people have heard of it.

73JPS
06-05-13, 11:35 PM
yeah thats not me. back to the mothball. im sure people have heard of it.

Well, ok... try the mothballs, then get back to us. I'll simply cut and paste a few comments from that Audi thread when you post. Capiche?

I will now quote the great poet Homer (Simpson, not the Greek guy): "Alcohol: the cause of, and solution to, all the world's problems!" and modify it slightly: "The Internet: the cause of, and solution to, all the world's problems!"

donavo
06-06-13, 01:57 AM
Well, ok... try the mothballs, then get back to us. I'll simply cut and paste a few comments from that Audi thread when you post. Capiche?

I will now quote the great poet Homer (Simpson, not the Greek guy): "Alcohol: the cause of, and solution to, all the world's problems!" and modify it slightly: "The Internet: the cause of, and solution to, all the world's problems!"

i think u mis-understood. thats ok. im sure u feel clever. i didnt mean i had intention to try it. i am curious if anyone of the older gents here has done this back when this was a common thing to do. as far as i know (from what i heard from my elder co-workers) this was a common thing to do for racers with heavily modded muscle cars. idk how ur clever little mind deduced that i intended to do this to an ATS, but i didnt. i simply remembered the subject while reading a post on this thread, and decided to ask about it. capiche?

73JPS
06-06-13, 08:22 AM
Yeah, sorry: I was a bit of a jerk on that one; never drink and post.

donavo
06-06-13, 10:56 AM
Yeah, sorry: I was a bit of a jerk on that one; never drink and post.

Lol it's all good man. If you know a way, we can delete both posts. I wasn't super nice myself.

73JPS
06-06-13, 02:27 PM
Lol it's all good man. If you know a way, we can delete both posts. I wasn't super nice myself.

Heck no: it's good to show some civility after all is said and done, and have some history on record to boot. I'll probably make lots more stupid posts in the future anyway.

Further to your question, turns out there might be something to the mothball thing, though in today's high tech world I sure wouldn't try it. I read somewhere on another forum that Myth Busters had in fact confirmed that mothballs could increase the octane rating of fuel; I didn't search this out for myself, however.

GJB
06-11-13, 04:32 PM
From Mobiloil.com


Mothballs increase octane. Believe it or not, this was once true. During World War II, naphthalene was the active ingredient in mothballs and octane ratings of gasoline were 60 to 80. Since naphthalene’s blending motor octane number is 90, mothballs could increase the fuel’s octane rating.

Today, though, modern mothballs contain para-dichlorobenzene (try saying that five times fast!) rather than naphthalene, but the latter is making a comeback due to toxicity concerns of the former. But considering the higher octane levels of today’s gasoline and the fact that naphthalene has a high melting point and can block jets and filters, mothballs are best kept in the closet.