[fastball]

Originally Posted by Larrio Andretti

You can add toluene to raise octane. I make my own race gas. I buy toluene at the paint store in 5 gallon containers. You can add a max of 10% toluene. Toluene is 114 octane so do the math. Recipes can be found online.

Don't. Just don't.

Unless you're an experienced race car driver driving a car intended only for the track do not go mixing chemicals with gasoline for your Camaro.

Good Lord

[RCF]

Originally Posted by fastball

Don't. Just don't.

Unless you're an experienced race car driver driving a car intended only for the track do not go mixing chemicals with gasoline for your Camaro.

Good Lord

Toluene is a normal component of gasoline, great octane, not too "light" or too "heavy". How much is already present in the gasoline you buy depends on mostly economics (how much it's worth for chemical uses vs fuels, what other high octane components the blender has available, etc) and environmental limitations, not anything that would cause harm to your engine.

[fastball]

Originally Posted by RCF

Toluene is a normal component of gasoline, great octane, not too "light" or too "heavy". How much is already present in the gasoline you buy depends on mostly economics (how much it's worth for chemical uses vs fuels, what other high octane components the blender has available, etc) and environmental limitations, not anything that would cause harm to your engine.

Yeah I just don't like recommending regular drivers do stuff like this on the forum.

Maybe take it to the racing sections.

[RCF]

Originally Posted by KingLT1

The only octane booster worth buying is Torco... can turn 93 octane into true 107 octane race fuel.

Octane does not blend linearly, but it's not exponential either. Linear is sufficient for back of the envelope calcs.

Their blending chart shows 5% max raises octane 14 points, but... they don't say anything about what starting or ending octane is. To blend 107 octane from 93 octane at 5% volume addition would require an octane rating of 373 on a linear basis - that doesn't exist. Something doesn't add up...

[RCF]

Originally Posted by fastball

Yeah I just don't like recommending regular drivers do stuff like this on the forum.

Maybe take it to the racing sections.

If someone can't find premium gasoline, I'd have no qualms recommending adding toluene on their own personally. 3 gals of pure toluene added to 17 gals of 87 octane gasoline should get you really close to a 93 octane blend.

[KingLT1]

Originally Posted by 14Black1LESS

Unless you are running 11:1 compression or more than you can safely use regular gas. GM released a statement back in 2003 or 2004 about this. I just wouldn't run it hard and like others have said you will lose a few hp but that's about it. There is no need for an octane booster either.

The LT1 is 11.5:1 compression. The LEA 2.4 in my GMC Terrain is also 11:1 and 87 is fine.

Originally Posted by RCF

Octane does not blend linearly, but it's not exponential either. Linear is sufficient for back of the envelope calcs.

Their blending chart shows 5% max raises octane 14 points, but... they don't say anything about what starting or ending octane is. To blend 107 octane from 93 octane at 5% volume addition would require an octane rating of 373 on a linear basis - that doesn't exist. Something doesn't add up...

yes it does right on the back of the can.

[Emig5m]

Just drive like a grandma until you can empty the low octane. Some dumb-dumb playing on his iphone pumped 87 in my Ford Lightning and the knock sensors on this vehicle are disabled in the computer from the factory because the supercharger sound interferes with them and I felt no ill effects driving out a tank of 87. I just made sure to baby it and definitely stay out of the boost, heh.

I think all modern vehicles will just auto adjust the timing if it detects knocking/low octane? But even if not, my Lightning with disabled knock sensors had no problem running 87 as long as I was gentle on the throttle until the tank was empty and I refueled with 93....

[KingLT1]

Yes all modern PCM's since 1996(launch of OBD-II) have high and low octane timing tables to compensate for bad gas.

[avalonandl]

Well it finally happened. I always use premium. I went thursday to fill up at Costco-save $ .30 a gallon on premium- and it was windy and cold. Swore I pushed the Premium button but I think the hose must have brushed against the regular button. Half way thru filling I look over and say f*%k to myself.... OK- just stop at 12 gallons. I am just driving it easy. Idle was a little rough on friday but no real effects I can tell otherwise.

[SSDan]

Originally Posted by avalonandl

Well it finally happened. I always use premium. I went thursday to fill up at Costco-save $ .30 a gallon on premium- and it was windy and cold. Swore I pushed the Premium button but I think the hose must have brushed against the regular button. Half way thru filling I look over and say f*%k to myself.... OK- just stop at 12 gallons. I am just driving it easy. Idle was a little rough on friday but no real effects I can tell otherwise.

I did the same thing at Costco a couple months ago.
Caught the mistake when half full. Switched back and finished the tank with 93. Filled again at a half tank then again at half tank and drove it easy during this period. Then went back to normal driving which usually includes a couple of rips through the gears somewhere in a drive. No harm - no foul as the car ran fine.

[avalonandl]

Originally Posted by SSDan

I did the same thing at Costco a couple months ago.
Caught the mistake when half full. Switched back and finished the tank with 93. Filled again at a half tank then again at half tank and drove it easy during this period. Then went back to normal driving which usually includes a couple of rips through the gears somewhere in a drive. No harm - no foul as the car ran fine.

It was to GD cold for me to stop.... wind was blowing hard..... Its not like I Drag race

[TJay74]

The colder weather makes it alot easier to run 87/89 with no issued. To be honest, the least amount of octane you can run that does not allow detonation will be the octane that makes the most amount of power in a vehicle.

[avalonandl]

These cars run fine 0n 87. I topped off with 93 yesterday, 6 gallons....

[TJay74]

Originally Posted by avalonandl

These cars run fine 0n 87. I topped off with 93 yesterday, 6 gallons....

While they run "fine" it is noted in the owners manual to not do it unless absolutely needed as it can cause engine damage that GM will not cover under warranty.

The low octane timing table can only reduce timing due to KR/detonation so much, if the detonation continue even with the timing pulled it will cause damage to the engine. These newer all aluminium engines are harder to hear detonation in as well, so it is possible to be detonating and not hearing it and causing engine damage.

Weather can and does play a huge variable in this as well, the hotter it is outside the more likely you are to have detonation become a variable because of your octane choice.