GAS 87 or 89oct?

[Joe PR5]

Hey, what do you guys run? 87? i have been on 87 and the other day i was like humm, i will try 89 and it feels soo much better! is it bad to mix like this? is it ok to start running 89?

 

[RaiderMS3]

My P5 likes Shell 87 Octane just fine. I have run higher octane in the past, but 87 works just fine.

 

[+ friction]

87 for me.

BTW, put on your flame suit...this has been asked a "few" times before.

 

[Joe PR5]

dont worrie im flame retarted.

 

[Natey]

 

[JunkPunch]

If your car is running better on 89 than 87, then there is something wrong with the car. The only reason it would run better on 89 is if you were getting detonation when running on 87, and that shouldn't be happening.

 

[zmepro]

grumble

 

[changedman]

there is no different. its all in ya head

 

[capnsavem]

87 monday thru friday, then 87 on saturday... but on sunday i use 87.... now dont even get me started on holidays becuase that's when i go to the 87.

 

[lncatch]

well correct me if im wrong, but higher octain burns cleaner, so if you got a lot of stuff up in there it will take a little longer to mangle your engine and injectors and stuff like that...thats what i was told once

 

[YelPro03]

well correct me if im wrong, but higher octain burns cleaner, so if you got a lot of stuff up in there it will take a little longer to mangle your engine and injectors and stuff like that...thats what i was told once

No, that is wrong. First you have to understand what octane is. It is an additive that retards (slows down) detonation required by higher compression engines, usually around 10:1 or higher. Now, some gas companies will try to get you to buy the more expensive higher octane fuel by adding additional "cleaning" agents in them. That is what you might be hearing. A lot of people really don't know what octane is and does. That's the short version. If you do a search on this topic you'll find a more lengthy explanition that I'm not in the mood to get into. Bottom line is the engine is designed to run on 87 then don't waste your money.

 

[zmepro]

well correct me if im wrong, but higher octain burns cleaner, so if you got a lot of stuff up in there it will take a little longer to mangle your engine and injectors and stuff like that...thats what i was told once

who told you that? chevron or shell?

you know, V-Power makes your car run better? and Techron give 5whp?

 

[zmepro]

those gas companys love to roll in the money of the people who fall for their advertising

 

[AlbinoMuntjac]

No, that is wrong. First you have to understand what octane is. It is an additive that retards (slows down) detonation required by higher compression engines, usually around 10:1 or higher.

Octane is not an additive in the gas at all. Straight from the FTC's Website:

Octane ratings measure a gasoline's ability to resist engine knock, a rattling or pinging sound that results from premature ignition of the compressed fuel-air mixture in one or more cylinders.

Simply put, it's a measure of how stable the gas is, not an additive to make it stable.
http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm
http://auto.howstuffworks.com/question90.htm

 

[NJP5Guy]

just use 87 and save your money. our cars run best on it. end of story. (drive) (strike)

 

[Pesty]

Here is a great article explaining everything you want to know but were
afraid to ask about how the octane ratings work and what benifits you will see
(or not) from using high octane fuels.

The nuts and bolts of it are....
1. All cars these days use some sort of EFI to regulate fuel/air mixture and burn.
2. Cars are designed to use fuel at specific octane. High performance engines
usually use 91+ octane, but most cars use 87.
5. Ther are NO benifits to using fuel rated higher than what the Mfg, recomends.


Good example,
My Prelude (may it rest in peace), had little notes all over it to use "premium"
fuel. In the owners manual it specifically said to use 91 octain or better.
I could tell a diference in the power and fuel economy if I put in 87. With 87 in
it it had about as much power and fuel economy as it did with 93 in it and the
A/C on.
Being since our p5's are designed to use 87, I could put in the expensive stuff,
but I'm not going to see any diference, other than in my bank account.

As for cleaning intakes and what not, that has nothing to do with the octane
rating, but rather is all about additives and the quality of the fuel.

 

[Midnight22]

just use 87 and save your money. our cars run best on it. end of story. (drive) (strike)

unless u have a mp3 ecu

 

[Khoifather]

My crazy uncle took my car to fill up the gas for me (hey what can I say, its free gas!!!) and he put in 94!!! I was like holy s***, he's crazy!!! But after a long trip, I actually got better gas milage! Usually I get like 160 miles at the half way point but this time, I got around 170-175 and thats from me blasting it home the whole time for about an hour.

 

[NJP5Guy]

unless u have a mp3 ecu

true...IF you have that in a p5.

 

[Pesty]

My crazy uncle took my car to fill up the gas for me (hey what can I say, its free gas!!!) and he put in 94!!! I was like holy s***, he's crazy!!! But after a long trip, I actually got better gas milage! Usually I get like 160 miles at the half way point but this time, I got around 170-175 and thats from me blasting it home the whole time for about an hour.

From everything Ive read if you are seeing better mileage or performance from
higher octane gas in a car designed to use lower octane, you probably need
a tune up. So far Ive gone through one tank of 87, and one tank of 93 in my
P5 and I haven't seen any diference at all. I also read somewhere that
running higher than intended octane fuel can leave unburnt fuel in your cat.
conv. But, I don't know how long it takes to build up to a point where it would
cause a problem.