ok i usually put premium fuel in my stang but recently i put in 87 and my car is slower..i mean i will punch it in 2nd gear around 30 mph and it will pull slowly...but when i do the same with 91 it pulls so much quicker..the reason i am wondering is because i have read a bunch of threads explaining that if there are no significant power mods added than premium is a waste of money...yet i have nothing but a catback and my car just pulls faster with 91...anybody with me on this one??
another octane question
- Thread starter reezy
- Start date
Venom_Nitrous
Founding Member
Sick96Stang
New Member
Trust me you dont get any more power from the octane rating of the gas you put in your car. Only thing the octane rating means is how slow the gas burns, you get no power gains.
The long explaination....
A higher octane rating means the mfgr has actually added compounds to the mix to slow down the flame front (burning) of the fuel. This is done to prevent "detonation" or "pinging" or "spark knocking" usually associated with high compression or SC'ing or hot weather (Austin) or a lean condition. Detonation is a bad thing and is to be avoided at all cost.
If your car will run on 87 octane without detonation or pinging, save the extra $ and buy that strut brace you've always wanted.
In fact (you probably won't believe this), if you run premium fuel in an engine designed to run on regular, you will actually lose power. Not really noticable, but because the fuel is burning slightly slower than with regular, it's not generating quite as much pressure and concequently not as much power. In higher compression engines the high compression more than makes up for the slightly slower burn rate of the fuel.
And to all you guys out there that will say, "...but my car runs better or faster or quicker, with premium. God and the petrolium manufactures love you and hope you never stop believing that and giving them your money.
A higher octane rating means the mfgr has actually added compounds to the mix to slow down the flame front (burning) of the fuel. This is done to prevent "detonation" or "pinging" or "spark knocking" usually associated with high compression or SC'ing or hot weather (Austin) or a lean condition. Detonation is a bad thing and is to be avoided at all cost.
If your car will run on 87 octane without detonation or pinging, save the extra $ and buy that strut brace you've always wanted.
In fact (you probably won't believe this), if you run premium fuel in an engine designed to run on regular, you will actually lose power. Not really noticable, but because the fuel is burning slightly slower than with regular, it's not generating quite as much pressure and concequently not as much power. In higher compression engines the high compression more than makes up for the slightly slower burn rate of the fuel.
And to all you guys out there that will say, "...but my car runs better or faster or quicker, with premium. God and the petrolium manufactures love you and hope you never stop believing that and giving them your money.
couple months ago I helped my friend install PI heads on his 98 GT and when we got his heads off oh my god did he have carbon build up I asked him what octane he runs and he told me 91.. over the years the slow burning 91 octane caused a ton of carbon build up I always run 87 octane in my 01 GT and 93 in my 02 supercharged GT..
That is a point worth remembering. Higher octane might be required for lower elevations, lean air / fuel ratios, high coolant temperatures, boost, increased compression ratios, and hotter air inlet temperatures. Your EEC can accommodate most of these changes, with the exception of boost and increased compression ratios.Jakes said:
