2005 Mustang GT Fuel
I am running 91 Premium lately only because I will be reflashing to the premium tune next week. Otherwise, she was running great on the regular grade gasoline. If it was a daily driver I would still be on regular gas.
computer flashed or not....obviously no one here understands the benefits of a better quality fuel....don't u/s if you know how octane ratings work or not...but if you purchase 87 octane fuel...you are purchasing fuel that is anywhere between 85 and 89 octane...ever noticed the +-2 on the fuel pump when you are fueling......if you purchase 89 octane you are either buying the cheap stuff 87 octane or up to 91 octane...there is a 2 point spread either way...including if you use the 93 octane.....the higher the octane the better the fuel burns...more oxygen means better burning mixture....no matter what you're computer is set for....just b/c your car is set to run on 87 octane doesn't mean that there is no benefit for running 93....just b/c your car know how to back timing out when it heres detination from 87 octane doesn't mean that is the best fuel to run in your car.....think about it as a big picture....
if you use less quality crap...then expect less quality from your car....save 2 dollars every time you fill up if it's worth it to you.
if you use less quality crap...then expect less quality from your car....save 2 dollars every time you fill up if it's worth it to you.
I think it says R+M over (divided by) 2 not +/- 2% I use 87 octane "Brand Name" fuel in mine. It's refined an extra step making it cleaner, so they say. I get the best mileage out of Chevron when I travel I try to look for it.
it is not a requirment to run 87 . take octane ratings out of picure for a moment ... then whats left? regular,mid grade and premium. there are more and better additives it the different grades. just like not all oil and filters are the same quality. also not all super / premium gas is the same. some are just alcohol ladden for the octane boost. not all ecu's can operate with higher octane.
here is and example, mercruser 502 efi's make more power on regular than premium because the ecu advances the timing looking for the knock from detonation and the adjusts the timing accordingly. so if it doesn't knock it just sets it a a lower defaut setting in case the sensor is going bad.
i the case of the newer cars they can tell the difference. they don't need it but in the long run they will have cleaner parts from the intake to the oil that you change. it is just finding good gas just not expensive.
one more point . i offshore power boat race...have won a world and national titles. my race boat runs on 91 to 93 octane and will run 86 mph all day. i bought super unleaded 93 octane at a different staion than normal and the boat would not go over 80 mph. the next day went to the station i use mre often and used thier 93 octane and in 5 min of running back to top speed. this problem was even worse in new jersy.the motor on nj gas would not even idle. fyi
here is and example, mercruser 502 efi's make more power on regular than premium because the ecu advances the timing looking for the knock from detonation and the adjusts the timing accordingly. so if it doesn't knock it just sets it a a lower defaut setting in case the sensor is going bad.
i the case of the newer cars they can tell the difference. they don't need it but in the long run they will have cleaner parts from the intake to the oil that you change. it is just finding good gas just not expensive.
one more point . i offshore power boat race...have won a world and national titles. my race boat runs on 91 to 93 octane and will run 86 mph all day. i bought super unleaded 93 octane at a different staion than normal and the boat would not go over 80 mph. the next day went to the station i use mre often and used thier 93 octane and in 5 min of running back to top speed. this problem was even worse in new jersy.the motor on nj gas would not even idle. fyi
Originally posted by 2005MustangGT@January 9, 2005, 11:02 PM
obviously no one here understands the benefits of a better quality fuel....don't u/s if you know how octane ratings work or not
obviously no one here understands the benefits of a better quality fuel....don't u/s if you know how octane ratings work or not
Octane rating is basically the fuels ability to resist combustion. In low compression or untuned engines IE standard mustangs a higher octane gas can actually slow down combustion, robbing your engine of HP and MPG.
Mustangs are tuned to use 87 octane, running higher octane gas gives you no benefit and at the worst can cause a loss of HP and MPG.
Originally posted by 2005MustangGT@January 9, 2005, 11:02 PM
computer flashed or not....obviously no one here understands the benefits of a better quality fuel....don't u/s if you know how octane ratings work or not...but if you purchase 87 octane fuel...you are purchasing fuel that is anywhere between 85 and 89 octane...ever noticed the +-2 on the fuel pump when you are fueling......if you purchase 89 octane you are either buying the cheap stuff 87 octane or up to 91 octane...there is a 2 point spread either way...including if you use the 93 octane.....the higher the octane the better the fuel burns...more oxygen means better burning mixture....no matter what you're computer is set for....just b/c your car is set to run on 87 octane doesn't mean that there is no benefit for running 93....just b/c your car know how to back timing out when it heres detination from 87 octane doesn't mean that is the best fuel to run in your car.....think about it as a big picture....
if you use less quality crap...then expect less quality from your car....save 2 dollars every time you fill up if it's worth it to you.
computer flashed or not....obviously no one here understands the benefits of a better quality fuel....don't u/s if you know how octane ratings work or not...but if you purchase 87 octane fuel...you are purchasing fuel that is anywhere between 85 and 89 octane...ever noticed the +-2 on the fuel pump when you are fueling......if you purchase 89 octane you are either buying the cheap stuff 87 octane or up to 91 octane...there is a 2 point spread either way...including if you use the 93 octane.....the higher the octane the better the fuel burns...more oxygen means better burning mixture....no matter what you're computer is set for....just b/c your car is set to run on 87 octane doesn't mean that there is no benefit for running 93....just b/c your car know how to back timing out when it heres detination from 87 octane doesn't mean that is the best fuel to run in your car.....think about it as a big picture....
if you use less quality crap...then expect less quality from your car....save 2 dollars every time you fill up if it's worth it to you.
Edit: And one more thing, quality and the octane rating on the fuel are not synonymous, the higher quality a gasoline (typically found at brand name stations such as Shell) have less impurites in the fuel. High quality fuel will also help clean the fuel system as well.
Originally posted by Indystang@January 10, 2005, 2:49 AM
I think it says R+M over (divided by) 2 not +/- 2% I use 87 octane "Brand Name" fuel in mine. It's refined an extra step making it cleaner, so they say. I get the best mileage out of Chevron when I travel I try to look for it.
I think it says R+M over (divided by) 2 not +/- 2% I use 87 octane "Brand Name" fuel in mine. It's refined an extra step making it cleaner, so they say. I get the best mileage out of Chevron when I travel I try to look for it.
Originally posted by Mellow Yellow+January 10, 2005, 9:36 AM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Mellow Yellow @ January 10, 2005, 9:36 AM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-2005MustangGT@January 9, 2005, 11:02 PM
obviously no one here understands the benefits of a better quality fuel....don't u/s if you know how octane ratings work or not
obviously no one here understands the benefits of a better quality fuel....don't u/s if you know how octane ratings work or not
Octane rating is basically the fuels ability to resist combustion. In low compression or untuned engines IE standard mustangs a higher octane gas can actually slow down combustion, robbing your engine of HP and MPG.
Mustangs are tuned to use 87 octane, running higher octane gas gives you no benefit and at the worst can cause a loss of HP and MPG. [/b][/quote]
Mello Yellow nailed it. I read an automotive mag article a while back that said the same thing. The lower octane fuel is MORE combustable, therfore produces more power for a given motor (if the motor is setup/designed to run on it). The need for less combustable fuels, i.e. HIGHER octane, is primarily to counteract preignition ("pinging") in higher compression (higher performance or non computer timing controlled) engines.
Made sense to me. I use 87 w/o incident.
i have 2 options for the gas i put in my stang, 95 or 97, so i typically just put in the 97 since i suspect it has the stations extra additives. i need to flash my system but i don't know if anybody has even tuned a stang for 95-97 octane gas yet.



