Gasoline

[akilli89]

I've searched for this but couldn't find anything.

I just averaged 29.2 MPG with my new intake, driving habits = I still think I'm a race car driver. lol.

I usually fill up using 87 octane, my dad (who is a ASE mechanic and knows A LOT) said that by using 91/93 octane gas, even though its more expensive (usually $.10-$.15/gallon higher) would pay for itself the first tank.

Then my grandfather (my dads dad) tried it in his 2002 Ford Ranger and nothing happened except he wasted a few dollars (he thinks).

any input on the situation? if no extra MPG, does it keep the fuel line clean or anything like that? I'm sure there is a reason its a bit more expensive.

btw, don't laugh at me because I think I'm Ricky Bobby. I wanna go FAST!!

Thanks in advance!

[g0ast]

From a website:

Can higher octane fuels give me more power?
On modern engines with sophisticated engine management systems, the engine can operate efficiently on fuels of a wider range of octane rating, but there remains an optimum octane for the engine under specific driving conditions. Older cars without such systems are more restricted in their choice of fuel, as the engine can not automatically adjust to accommodate lower octane fuel. Because knock is so destructive, owners of older cars must use fuel that will not knock under the most demanding conditions they encounter, and must continue to use that fuel, even if they only occasionally require the octane.

If you are already using the proper octane fuel, you will not obtain more power from higher octane fuels. The engine will be already operating at optimum settings, and a higher octane should have no effect on the management system. Your driveability and fuel economy will remain the same. The higher octane fuel costs more, so you are just throwing money away. If you are already using a fuel with an octane rating slightly below the optimum, then using a higher octane fuel will cause the engine management system to move to the optimum settings, possibly resulting in both increased power and improved fuel economy. You may be able to change octanes between seasons ( reduce octane in winter ) to obtain the most cost-effective fuel without loss of driveability.

Once you have identified the fuel that keeps the engine at optimum settings, there is no advantage in moving to an even higher octane fuel. The manufacturer's recommendation is conservative, so you may be able to carefully reduce the fuel octane. The penalty for getting it badly wrong, and not realising that you have, could be expensive engine damage.

Basically it says "no".
The only time you would really need to change it is if you change the compression ratio of the engine and/or get a turbo/super charger, and/or if you get your engine tuned (and not just a "chip", I'm talking about EMS reprogramming). Why? Because boosting the engine alters the fuel/air mix and altering it requires a richer fuel to prevent knocking.

Putting a higher octane fuel in a lower octane car is like putting wine in a beer bottle... (Insert witty comparison here).

[xtreme 2]

yup... higher octane gas prevents the "bad" kind of detonation... when you have higher compression or a turbo, you use it because it burns finer and the engine won't go boom on you...

[AVE0SAM]

you won't gain any mpg or power from using high octane fuel in a stock aveo, you might even lose some mpg from doing it, but from what ive heard you can use it even now and then to clean the fuel system

[AveoRob]

the higher the octane, the more resistant to combustion. that is why in a higher compression engine the gasoline with a lower octane rating will ignite prematurely from hot spots on the cylinder walls causing knock. All gasoline comes raw from a few refiners and most branded gasoline, i.e. Exxon, Shell, etc. add detergent additives to "keep you valves and stuff clean". this doesn't work with a tankful. It is therefore a total waste of money to burn anything above the recommended octane rating as the above article states. If you want to clean your valves buy a good additive.

[mtlswift]

Higher octane in cars that don't need it is a waste of money. You'll also end up forming a lot of carbon deposits if you run it continually.
Modern cars that use premium can usually run lower grade fuels without too much complaint cuz the computer/car is adaptable enough to pull timing etc... you just end up lowering performance, amount is about equal to the difference in the price between low and high grade... e.g. if low grade costs 10% less, you end up losing 10% hp.

I usually run 1 full tank premium come May-ish to flush out the crappy winter-grade gas.
Also, if you store your car in the winter, you should also run a full tank of premium when you take it out cuz of the extra additives etc to help flush out old gas with the fuel stabilizer.

[akilli89]

alright, thank you for all of the info.