ArcticZ28

iTrader: (14)

Is there any truth to this statement? I've wondered for a while but can't think of anything that would make me believe it. Maybe you all have some ideas as to whether or not it's true, somewhat true, or just blatantly false (and maybe why it came to be "word on the street").

Kalgorn

iTrader: (6)

I've heard of this before. A buddy of mine once told me he runs 93 once a month to "clean things out" and then just runs 87 otherwise.

However in these cars, how could you run a higher octane? We're supposed to be running premium anyway. I hope you're not running cheaper gas...

ArcticZ28

iTrader: (14)

Nah, I run 93 although I could run lower. I do run 87 in my 97 cavalier though. Was wondering what good anything like 89 or even 93 could do for it other than provide decreased gas mileage from the slower burn.

NDFORSPD

How much milage on the cavalier?

Flawless02SS

iTrader: (9)

Dont know, but I know its better than the Z28, lol

ArcticZ28

iTrader: (14)

How much mileage is on the clock or how many mpg do I get? It's got almost 80k on it and gets anywhere between 26-27mpg with 70% highway driving. The z28 gets 11mpg

Cld069

iTrader: (2)

I dont see how a higher octane would "clean". I know you understand the differences in octane. But a higher ocane isnt going to clean, its not made to. Products like seafoam which have properties to get rid of carbon build-up are your cleaning agents. IMO running a higher octane to "clean" is a myth. Stick with seafoam.

staringback05

iTrader: (8)

ill run it in my truck once in a while....i will say that tank and the next tank do run better....

ArcticZ28

iTrader: (14)

I dunno... I guess it would very much depend on the stock tuning in the car. There's all that talk about high octane tables that you can sometimes venture into when running a grade higher octane (possibly a myth as well?). My cavalier doesn't seem to like it though. It certainly doesn't get better mileage, that's for sure. And, I have this long standing SES light that is a P0420 code (code of death b/c it could mean a bunch of different things that you don't know till you replace) that had gone away for about a month or so, which never happens. I had been running 87 for all that time as well. Then, the other day I filled up with 91 to try this myth (or not) out again and the damn light came back on I was on such a good roll!

SladeX

octanes have nothing to do with cleaning, it has everything to do with how it combusts. Higher octanes tend to have slow burns, which do nothing for cleaning squat. Higher octanes resist detonation better because of that, under compression and higher temps it won't detonate as easily.

Our engines need 91 octane to run. That is what the tune is optimized for. 93, 94 octane is a waste to your wallet unless your car has been tuned to use it. You won't dyno any higher in more or less stock/bolt on form because you use 93 octane. You WILL lose power if you run less than 91 though due to your engine having to run with low octane tables.

Your mileage won't change if any from using 91 or 94. You will notice a change if the methanol content in the gas you are using is higher in one fuel brand compared to the other. (More methanol = less power per volume, but cleaner burn which is not to be mistaken for something that can "clean" your engine).

ArcticZ28

iTrader: (14)

Yea, I understand everything about octane, which is why it never really made sense to me. The only thing I wasn't sure about was whether a higher octane had a better chance of cleaning somehow.

Wolfgang427

iTrader: (48)

The myth came about because in the older days premuim gas not only had higher octane but had more detergents then regular gas. In these days all name brand gas octanes have detergents in them so the myth is no longer true. If you don't need the extra octane then running premuim is a waste of money. Better off putting a extra detergent cleaner every few tank fulls of gas. Redline makes a good one (it's been approved by BMW) or Chevron with Techron.

ErikElvis

iTrader: (1)

Just run some FP60 now and then. Its cheap!

Sneakyws6

In all actualality it will not clean but might actually leave more deposites if the motor is not designed to run the higher octane fuel.

Ever seen a motor that was suppossed to run 87 but had 91 ran thru it all of the time. I have and the intake valves are usually gunked out. We see this alot on motorcycle motors where people are running to high of a octane gas for no reason.

The best thing you can do for a motor is run the highest octane needed that keeps the motor from detonating under a load. Nothing more, nothing less. This will yield you the most hhorsepower and the best fuel mileage as the car will be able to burn the fuel completly.

I run nothing but 91 in my Formula. I Seafoam mine once or twice a year and change the fuel filter twice a year. To this day I still get 20mpg on average driving thru the city on my normal weekday drives and the car has almost 80,000 miles on it.

NDFORSPD

I agree with sneaky, use the 87 unless your car is detonating on hills and under load in which case 89 can take it away. We had this happen on my parents' 3.3V6, it ran great up until almost 130k mi on 87, and then would ping like a **** with the slightest load increase(you could hear it CLEARLY...ping ping ping!). We immediately switched to 89 octane and never had a problem ever again. I did every few months(lol, i was lazy so ill avg it out to every oil change) put in STP fuel injector cleaner.

NOW, I would get my injectors serviced at gm(Im not too sure what the stuff is called, but its run directly into your fuel rail), and you can feel the difference after that. I think it's 100 bucks, but my bud did it on the side, so it was just 20 bucks in fluid(and half my pack of smokes whie waiting for it to run thru!)The only other time I or my parents will up the octane is when towing on hot summer days, other than that its min. octane recommended.

PaulC

I guess the only way for you to find out is to do it.