What fuel octane is everyone feeding their 3G's? (V6 GT - GTS) ..........aka regular,plus, or super

 

should be super

 

I ALWAYS give my car what the manufacturer recommends. I've read quite a bit about fuels and found it's pointless to give the car a hgiher octane rating than necessary. Now once you start getting into the bigger upgrades (Turbo and whatnot) and you start making real power you're going to need to look at your fuel type. Basically the higher octane takes more compression to actually burn (From what I've gathered). So let's say your pushing a good amount of boost and have a fairly built engine now that '89 octane fuel you've been using is going through compression ignition. Basically means that the fuel isn't waiting around for the spark to go boom it's doing it when it feels like.

This is a BAD thing. The combustion process is designed to be a controlled thing and fuel igniting when it feels like it A.) Doesn't give optimum performance, and B.) can damage the engine. You'll hear a bit of a knocking of pinging when this predetonation happens. This is an indication you need to go up a level in your octane ratings.

On the other side of the coin though using the higher octane in your stock engine serves no purpose either. Again think about the ignition. Now you're making your engine ignite this fuel but during the duration of the spark the fuel refuses to ignit till the very end. Now you'll get unclean burns as the fuel is still burning when the exhaust valves open up.

Essentially all I'm saying is use the rating recommended by the owners manual until you do upgrades and remember to run injector cleaner through the system every 30K miles. (I think that covers about all of it... Anyone see anything I missed?)

 

Found this link to an explanation. It has some good info

http://www.sportcompactcarweb.com/ed...hno/index.html

talks about all the things you are asking and how living in CA can really suck for tuners

 

Aw not gonna just up and tell me how far off I was? JEEZ... Gonna make me read MORE gas shyt to remember what I already read...

 

Real Close Sanguinius.

The octane rating in fuel is related to how much pressure (compression) it takes to have it explode. Normal gas, with a rating of 85 (ish) will have more of a tendency to pre-ignite (go bang before its lit) than would say... Aviation fuel octane of about 104.

Note, all gas goes bang when you light it, octane rating doesn’t really mean anything here.

Lower the octane rating, lower the cost. Higher the octane rating, more compression it can handle without pre-igniting (ping). There are some formulas out there that could tell you, based on your compression ratio, what kind of octane rating you should be running, but as Sang said, unless you are pumping a lot of boost, there is absolutely no advantage in running higher end gas. On the flip side, there are NO down sides to running high octane gas.

Note, Aviation fuel = leaded gas.... so don’t pull up to your local air port and fill your car with 104 octane fuel cuz it will eat your fuel injectors and fill up your catalytic converters (assuming you still have those)

 

From my experiance, if you have an older car, its better to run higher grade gas, I had a 95 Grand am, and it made normal engine ticks, but when I put high grade in, it ran with no ticks. But dont mix fuels, its bad for ya car. My 2 cents.

 

i'm not sure what the manual recommends for your car but i'm pretty sure it is going to be something like 89-91. I would just go with 91, whatever that maybe be (probably super)

 

you crack me up san.


....i was just curious about it because i didnt see the big difference of downgrading to plus -the car has been perfectly ....nevermind i wont even say it ...i know ill jinx my self - the other day i was talking to someone about speeding tickets and that night i ended up getting one - talk about jinxing yourself