: Regular Gas

Big Jake
11-01-03, 12:43 PM
This has probably come up before, and if so I do apologize.

I have a '97 SLS that uses premium gas. I live in the Dallas, Tx. area and we have a car expert, Ed Wallace, That states my car will run just fine on regular.
Ed reviews cars on T-V and also has 5 hour auto show on KLIF, 570 radio.

He states that all recent cars have a computer that will adjust for reg. or prem. gas. He states that in order to get the horsepower and the gas milage advertised, you must use premium gas. If you are satisfied with a little less horse power and less gas mileage use regular as there will be no harm to your engine. He further declares this is why you no longer see any ads regarding the benefits of Ethyl or premium gas.

At 20 cents difference in the price between reg. and prem. this might be something to think about.

What say you? Please reply.

Big Jake

11-01-03, 12:49 PM
i have a 1994 STS and i do need the HP but i Dont need the HP... so???

11-01-03, 12:57 PM
Just a thought, but you might get more replies to this if it was in the Northstar section and not hte appearance and detailing forum. But with the great moderators we have it'll probably get moved there anyway :)

I don't have a '97 Cadillac and don't know those engines, but if the owners manual says it can be run on less then premium you could always try it and see what it's like. I've never noticed big enough difference in milage myself to make it worthwile paying more for premium but at the same time none of my cars recommend to use it.

11-01-03, 01:03 PM
Edit: A mod will come and move this for you!!!!!

Dont run regular...... Its not worth it, plus, you could damage your engine.... Sure, the computer WILL compensate for it, but only to a certain point...... If it starts knocking even after the computer has compensated all the way, your screwed.....

The MFG says to use premium for a reason.... Believe me, if they could get away with requiring regular, they would......

11-01-03, 03:30 PM
I'm here!! :)

11-01-03, 03:53 PM
Wes is correct. The "expert" from Dallas should be more careful about making such sweeping generalizations. In "theory" he's correct, but in practice there ARE several cars that have been calibrated by their OEM in such a way that even once their on-board computer has "compensated" for the lower octane fuel to the best of it's ability, the engine may STILL detonate. And detonation is deadly to engines. So go price a new Northstar and see how many years of using the lower octane fuel it will take to pay for it when it blows.
FYI: just in case you weren't aware of it (and I'm VERY sure you're not, since it was NOT made public), Cadillac Engineering circulated a "memo" back in the late 90's concerning this very issue. It stated that you could use lower octane fuel if you wanted and the only penalty you would pay would in MPG and 0-60 performance. Shortly after they issued that memo, field testing showed that they were quite wrong and that even semi-high mileage Northstars experienced moderate to severe detonation when using anything less than "Premium" fuel. The memo disappeared and was never spoken about again. I know this because I was the field tester that initiated the memo back to Cadillac Engineering concerning the detonation problem. ;)

11-01-03, 10:17 PM
Beside that..... YOU DRIVE A CADILLAC.... It was once 50k..... It still thinks its a $50k car....... Give it the good stuff, and she will make you happy...!

Night Wolf
11-02-03, 04:43 PM
I know on the 4.9, there is no knock sensor....and I havn't be bold enough to run regular, I don't care though, I want all the power I coudl get, but my enigne is too clean/great running to risk anything.....

...I know the newer N* run on regular (one of Motor Trends pros when testing the new DeVille "300hp on regular gas") but for the whole buck you'd save...not worth it.

on a side note, anyone notice something...... premium at Sunoco used to be 93, and then they had Ultra 94, when I went there today, premium was 91 and Ultra was Ultra 93....what's up with that? regular and mid-grade are still 87 and 89.........

11-02-03, 06:03 PM
Ooooh.... 94 octane..... Never seen that!!!!

Night Wolf
11-02-03, 07:27 PM
Ooooh.... 94 octane..... Never seen that!!!!


Sunoco has it all the time, called Ultra 94, they are the only gas place that has 94.... it is usually like 5-8 cents/gal more thenb Premium.......

11-03-03, 03:32 PM
Probably not worth it..... Usually octane is subjective anyway.......

11-03-03, 03:43 PM
Probably not worth it..... Usually octane is subjective anyway.......

I work part-time for Sunoco. 94 has been around for years. To let people in on a secret:
Sunoco does not have 89 or 93 octane gas. They only have 87 and 94. They mix the 2 to get the different combos. Now about the 94 being worth it. No it is not unless it is on special where its 1 or 2 cents higher than 93 other than that its not worth the cost.

11-03-03, 03:47 PM
Even at that, what is one octane point gonna do for you... Sure as hell it aint gonna prevent detonation over 93, and ill venture to say even from 92!!!

11-03-03, 03:49 PM
Even at that, what is one octane point gonna do for you... Sure as hell it aint gonna prevent detonation over 93, and ill venture to say even from 92!!!

Have you ever put 87 in a junker than ran 89 later on. Did you notice the difference.

11-10-03, 12:46 PM
Just pay the extra $.20 per gallon (or 2-3 dollars extra per fill-up). If you don't put premium in, you lose HP. This loss in HP will make your engine have to work harder to achieve and maintain speed - ANY speed. Because of this, your engine will use more (cheap) gas to get you where you need to go. In the short run, you will probably save +-$.05 per gallon, BUT we haven't even started to talk about accellerated (sp) wear and tear on electrical components that have to compensate for the lower octane. This expert's statements are too broad. You have a car that requires premium fuel. You can either pay as you go, or pay a little now and have to pay a bigger chunk later... and still go without peak HP for all that time. It doesn't sound worth it to me.