Better gas, Better Km/L?

EthanMKIII · 09-22-2008, 01:33 AM

Hey right now i'm pumping 89 octane in my 88 turbo 5 speed supra. I get around 7Km/L, will i get better km/L if i put in 91 octane? Just wondering.

Chambers · 09-22-2008, 01:19 PM

It really depends, you may get a little bit more fuel economy out of it, but it probably wont be noticeable. The plus would be your running better fuels in your car so it will run cleaner.

Good luck.

Supra Greg · 09-22-2008, 06:16 PM

I agree with what he said...

better gas = better performance and milage.. but it all depends on just how much better the gas is.....but you can see 1 or 2 mpg more.. bigest thing is the foot.... and speed limet... @55 mph you will get alot better milage then 75mph...

Grandavi · 09-22-2008, 06:27 PM

I dont know about that... the car cruises at 70mph without much fuel.. lol. I have trouble keeping it under that speed on highway, it just feels like its idling under that speed.

shiftysupra · 09-22-2008, 11:30 PM

I will have to 110% disagree with this... Here is the breakdown of fuel... 91 octane Premium (or 92 in some places) contrary to what people say does not "burn cleaner". You do not get better gas mileage. The higher the octane the less likely detonation is to occur, that's all. In order to get more power you need more air/fuel mix ratio forced into the combustion chamber... In other words the octane rating does not relate at all to the energy content of the fuel, only the likelyhood of the fuel to burn rather than to explode (detonate). Compression is what relates to power and as compression increases so does detonations proabability but so does power. What do you think a turbo does?? Thats why people put thicker head gaskets and higher octane fuel to compensate when putting on a turbo because with more air means more compression, and more compression means detonation... However if we were to all ran N/A compression and REALLY high octance fuel, detonation would less likely occur... (theoretically) but each build is it's own... I think you guys get it.... ALSO when you go to a gas station that offers reg, mid, and prem fuel there is only 2 tanks of fuel: low octane and high octane. Premium means that you get more from the high octane tank and a little less from the low octane. Hence why when you see a gas truck there are only 3 outlet holes in the trailer: Low octane, High octane and Desiel.. Hope that answers some questions.

Since everything we are doing to our cars is a science if we study how everything works together we could tune our cars more effectively.... No go burn some rubber....

09-22-2008, 01:33 AM	#1
EthanMKIII 3" Exhaust Join Date: Aug 2008 Location: BC Posts: 71	Better gas, Better Km/L? Hey right now i'm pumping 89 octane in my 88 turbo 5 speed supra. I get around 7Km/L, will i get better km/L if i put in 91 octane? Just wondering.

09-22-2008, 01:19 PM	#2
Chambers walbro fp Join Date: May 2007 Location: USA - Harford County, Maryland Posts: 481	It really depends, you may get a little bit more fuel economy out of it, but it probably wont be noticeable. The plus would be your running better fuels in your car so it will run cleaner. Good luck. __________________ Whats in the garage, well.... in the yard. 1986.5 Toyota Supra - NA - 5 spd 1986 Ford Ranger Lowrider - 5 spd 1984 Ford Ranger XLT - 7" Lift - 4X4 - Auto "Stuck in the 80's"

09-22-2008, 06:27 PM	#4
Grandavi walbro fp Join Date: Jul 2008 Location: Calgary, Alberta, Canada Posts: 410	I dont know about that... the car cruises at 70mph without much fuel.. lol. I have trouble keeping it under that speed on highway, it just feels like its idling under that speed. __________________ My Links: What I am doing... http://www.toyota-supra.info/forums/...part-list.html My questions http://www.toyota-supra.info/forums/...w-answers.html

09-22-2008, 06:16 PM	#3
Supra Greg 3" Exhaust Join Date: Sep 2008 Location: Florida Posts: 64	I agree with what he said... better gas = better performance and milage.. but it all depends on just how much better the gas is.....but you can see 1 or 2 mpg more.. bigest thing is the foot.... and speed limet... @55 mph you will get alot better milage then 75mph...

09-22-2008, 11:30 PM	#5
shiftysupra 3" Exhaust Join Date: Jan 2006 Location: Arizona Posts: 96	I will have to 110% disagree with this... Here is the breakdown of fuel... 91 octane Premium (or 92 in some places) contrary to what people say does not "burn cleaner". You do not get better gas mileage. The higher the octane the less likely detonation is to occur, that's all. In order to get more power you need more air/fuel mix ratio forced into the combustion chamber... In other words the octane rating does not relate at all to the energy content of the fuel, only the likelyhood of the fuel to burn rather than to explode (detonate). Compression is what relates to power and as compression increases so does detonations proabability but so does power. What do you think a turbo does?? Thats why people put thicker head gaskets and higher octane fuel to compensate when putting on a turbo because with more air means more compression, and more compression means detonation... However if we were to all ran N/A compression and REALLY high octance fuel, detonation would less likely occur... (theoretically) but each build is it's own... I think you guys get it.... ALSO when you go to a gas station that offers reg, mid, and prem fuel there is only 2 tanks of fuel: low octane and high octane. Premium means that you get more from the high octane tank and a little less from the low octane. Hence why when you see a gas truck there are only 3 outlet holes in the trailer: Low octane, High octane and Desiel.. Hope that answers some questions. Since everything we are doing to our cars is a science if we study how everything works together we could tune our cars more effectively.... No go burn some rubber....