Octane boost

[eightsandaces]

I occasionally like to run octane boost, it seems to make the car smoother. I have used 104+ and the stuff made from jet fuel, both work well. A recent trip to the dollar store and I found what looks to be toluene booster, is this stuff safe to use?

[Lobo1186]

yes it is safe... at least as far as I have ever read. however i do believe since it lacks detergents that it can cause more soot buildup in the motor. but for once and a while basis it shouldnt be harmful.

HERE IS AN OCTANE MIX CALCULATOR

if you use xylene or toluene (i forget the octane rating of those) just use the calculator. personally I would rather use race fuel found at any race track. much simpler and I think cheaper.

[Cloudsurfer]

Originally Posted by eightsandaces

I occasionally like to run octane boost, it seems to make the car smoother. I have used 104+ and the stuff made from jet fuel, both work well. A recent trip to the dollar store and I found what looks to be toluene booster, is this stuff safe to use?

Hate to burst your bubble on this, but Jet-A is basically kerosene, and has absolutely no place anywhere near a piston engine. Furthermore, if you actually look at independent tests, the most you will ever gain by either adding toluene (up to about 20% by volume) or pretty much any of the variety of store bought octane boosters (used at their maximum concentration), is about 2 octane points. However, since these methods work by raising octane at the expense of combustion quality (they create a slower burning fuel), you'll actually make less power, especially on a high revving engine, and in some cases, the fuel burns so slowly that it will still be burning as it exits the exhaust valve, which is a great way to destroy O2 sensors and cats.

There's a huge difference between high quality (racing fuels, leaded AvGas (for piston aircraft), high octane gasoline, and "modified" street fuels. Start pricing out cans of "Jet Fuel Octane Booster" or toluene (per gallon, at a high enough concentration to make a difference) and you'll quickly find it's cheaper to just run 100 unleaded race fuel if you have a car that needs it (which if you have a remotely stock Boxster, you don't).

What I'm anxiously waiting for, is the aviation world to switch over to a 100 octane unleaded fuel (and AvGas is rated on the MON scale, which is conservative compared to the R+M/2 scale used in the auto world in the US, so the 100UL AvGas will actually be around 104 octane R+M/2.

[eightsandaces]

Cloud,

That's why I asked, I only used it occasionally, as far as "bursting bubbles" if the 104+ didn't make a perceptible difference do you think I'd still buy it? Whether it's bad for the engine is an entirely different subject. I'll start looking for 100 or competition car gas. I've only seen it in a few places, best one can do near me is Sunoco 93.

[JTP]

Originally Posted by eightsandaces

Cloud,

I'll start looking for 100 or competition car gas. I've only seen it in a few places, best one can do near me is Sunoco 93.

Delta Sonic sells race gas (I think 103 octane) in upstate NY. Here's where they're available:

New York:
Ridge & Langner Rd., West Seneca
2285 Walden Ave., Cheektowaga
2590 Delaware Ave., Buffalo
Niagara Falls Blvd.& 80th St., Niagara Falls
4983 Transit Rd., Williamsville
990 West Ridge Rd., Greece
2970 West Henrietta Rd., Henrietta

Illinois:
159th & Oak Park Dr., Tinley Park
1415 Ogden Ave., Downers Grove

[Cloudsurfer]

Originally Posted by JTP

Delta Sonic sells race gas (I think 103 octane) in upstate NY. Here's where they're available:

New York:
Ridge & Langner Rd., West Seneca
2285 Walden Ave., Cheektowaga
2590 Delaware Ave., Buffalo
Niagara Falls Blvd.& 80th St., Niagara Falls
4983 Transit Rd., Williamsville
990 West Ridge Rd., Greece
2970 West Henrietta Rd., Henrietta

Illinois:
159th & Oak Park Dr., Tinley Park
1415 Ogden Ave., Downers Grove

Most Delta Sonic's that I've been to have straight 100 Octane unleaded. Great stuff.

[Lobo1186]

if you cannot get race fuel you can go just to home depot and buy xylene or tuolene. if you google it you will get a plethora of info and you can use the above supplied calculator to mix your own!

[986FortyEight]

There has been some serious threads on the subject in the past on this board and others, and it seems that unless you reprogram your DME to use maps built with high octane gas into consideration, there is no particular performance related advantage to running higher octane gas in your stock boxster.
But if it makes you happy...

[Lil bastard]

Noticeable difference = Placebo Effect!

These additives raise the octane rating only a few tenths of a point.

To get any real gains, you need 10-20% by volume which equals 1-2 gallons of the stuff on a Boxster, and then, you'd only see a mild effect on performance.

On the other hand, these things are powerful solvents and will reek havoc with your engine oil's additive pkg. necessitating more frequent, expensive, oil changes.

Long term they will negatively effect the fuel system components - fuel lines, connectors, plastic sending units, etc.

Save your money... they're not really worth it.

Cheers!

[Cloudsurfer]

Originally Posted by Lil bastard

Noticeable difference = Placebo Effect!

These additives raise the octane rating only a few tenths of a point.

To get any real gains, you need 10-20% by volume which equals 1-2 gallons of the stuff on a Boxster, and then, you'd only see a mild effect on performance.

On the other hand, these things are powerful solvents and will reek havoc with your engine oil's additive pkg. necessitating more frequent, expensive, oil changes.

Long term they will negatively effect the fuel system components - fuel lines, connectors, plastic sending units, etc.

Save your money... they're not really worth it.

Cheers!

Glad to know we're on the same page with this

To continue the "is it safe" discussion, consider that at 20% concentration (enough to actually make a difference, toluene or xylene, as solvents, offer zero lubrication, and significantly degrade the lubricity of the remaining gasoline. This has obviously negative effects on things like fuel pumps, but is also particularly bad for the upper cylinder area, which relies partly on the fuel to lubricate the rings, and the rest on oil. They will also eat away at the fuel system. Adding a strong solvent to the mix washes the oil film from the cylinder walls, and you will experience increased cylinder bore and ring wear. Whatever small amount that makes it past the rings will degrade the oil, and cause increased bearing wear, also necessitating more frequent oil changes to try to combat this effect (added cost).

Both of these chemicals are also incredibly toxic to handle, and dispose of their containers.

Some will point out that, yes, Formula 1 cars used to run almost straight toluene, and that's true. Their motors also only had to last one race, and it was human health concerns that caused F1 to ban the fuel.

Lobo, I'm not sure where you're getting your information, but substituting solvent for fuel on a street car that doesn't get its engine rebuilt every few races is not a good idea, nor is handling this stuff on a regular basis.

To put this into practicality, last time I saw toluene at Home Depot, it was about $10/ gallon. Substituting 20% toluene (at $10/gal) with 80% premium unleaded (call it $3/gal) yields an overall fuel cost of $4.40/ gal. You can buy 100 octane race fuel for that price, and that is a high quality, safe fuel (both for your health and the health of your motor).