I live in California home of the highest gas prices in the nation. I know this may sound like a dumb question but here goes... HOW IMPORTANT IS IT TO MY '05 WRX WAGON TO CONTINUALLY FILL UP WITH PREMIUM (91 octane) GAS? What happens if I put in a lower grade gas? Will there be any engine damage? PLEASE HELP ME!!!
my older crappier cars get better mileage on premium so would it stand to reason that a WRX which is tuned for 91-93 octane gas would get better mileage on 91 than on 87...
Just an example, my wife's taurus wagon gets 25 mpg on premium
it gets 20 mpg on regular (this is on my daily commute tested with 2 tanks of each)
sooo... if premium were $2.50 and regular were $2.01 it would be CHEAPER to buy premium. CHEAPER per mile without regards to knock or any other engine wear.
Course I am in texas and premium is 93 octane, so it will not be as dramatic in Cali.
It will prevent knock (which WILL kill your engine).
Can a stock mustang GT beat you if you are running 87 and he is running 91?? probably
The best thing for you to do is stick to the fuel that the engine requires. The octain is higher for a reason. If you run on 87 or even 89 for that matter, your car will run like a piece of sh!t. It won't be fun. Then things will start going wrong. It'll start with sluggish behavior, then knocking, then you'll start having to tune your car too often because you'll be eating up spark plugs. I know it's expensive, but you just gotta deal for now.
Rain_Racer said:
Can a stock mustang GT beat you if you are running 87 and he is running 91?? probably
thanks for the unanimous voice to keep the premium. I wish they had higher grade in CA too, but only if its as cheap as it is elsewhere in the country.
*sigh*, that is quite a draw-back. You may want to read up on water injection. I read a tech article in Turbo Performance Mag. today about it and using it to up horsepower, lower intake charge, and (this is for you) raise the detonation threshold. They never spoke of being able to run a lower octane with H2O injection on board, but if you can't, I'd like to know why not.
While I agree with #2-4, #1 is wrong. Legally, unless they supply the fuel for you, they cannot void your warranty by running other fuel. Same thing with oil, coolant, transmission fluid, etc...
While I agree with #2-4, #1 is wrong. Legally, unless they supply the fuel for you, they cannot void your warranty by running other fuel. Same thing with oil, coolant, transmission fluid, etc...
While I agree it SHOULD be wrong I must disagree and side with reality. There is a label on the gas cap/door and the dealer when you buy is very firm and clear about using Premium unless you are without any other choice.
If they are going to void you for having a cat-back they will certainly be willing to void you for using low-octane grade fuel. On the same page if they tell you to use 5W-30 or 10W30 and you use 15W-50 which is not in the acceptable range then they can void you for it. You have to use what meets their requirements.
The legally can't void your warranty for that. Ford got into trouble for that recently. Unless they are supplying something free of charge, legally you do not have to use it to maintain your warranty.
thanks for the unanimous voice to keep the premium. I wish they had higher grade in CA too, but only if its as cheap as it is elsewhere in the country.
Here's a little experiment:
Next time's your tank's low, give yourself a Christmas present and spring for a couple of gallons of 100-110 octane gas, then tell us what you think.
110 octane would be leaded gas, which would be really bad for the car. i belive that the highest un-leaded gas that exists is 100, or maybe a 104. the way i understand race gas is that it is the lead that raises the octane content.
If I remember correctly the lead in gas was used to allow for higher compression ratio without knock. Basically instead of increasing octane they added lead.
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