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racing fuel

3K views 7 replies 7 participants last post by  everycredit 
#1 ·
i will be entering my 2001 C240 in an autocross event this weekend, and i know a local gas station sells race fuel. i was wondering if anyone knows anything about using high octane fuels in cars like my own. i also worry that the fuel might be leaded, i will be sure to check before i buy, but i was wondering if anyone knows anything about leaded fuels.

thanks.

C. Deutschler

p.s. if anyone lives in the atlanta area and cares to join a fellow benz enthusiest, be sure to contact me
 
#2 ·
Unless you modified the engine and increased compression (cams, pistons, head with larger valves, fuel management, etc), adding more octane does not translate into more power. I dynoed my C230 with a pulley kit for about 50% more boost, had Renntech exhaust, itg airfilter and I dynoed 100 octane 76 unleaded with zero increase in power over 91 octane. I even ran the entire tank through to make sure the ECU adjusted to the higher octane fuel before doing the dyno. Also, if it were going to make a difference, it would do so in CA where it's hotter and arid and more likely to ping, afterall, does it get to 110F with < 10% humidity in Atlanta, I don't think so.... If you want more power, sell the car and get a nice clean used 2002 C32.
 
#3 ·
Leaded Fuels

Leaded gasolines are a big no-no with modern vehicles. They build up in the catalytic converter and will pretty much guarantee a voided emissions systems warranty.

But I assume that if you are hot rodding an MB you probably don't care about your warranty. I would suggest trading in the car and buying a ricer.
 
#4 ·
If you want True Race Gas go to Sherman Williams (yes not a typo). Toulene is the best stuff. Its 114 octane UNLEADED race fuel. All you need is 1-2 gallons per tank to boost your octane from 93 to 96+ or from 91 to 94+. I alwasy yes it and YES it makes a huge difference as far as engine responce, engine does not pull timing b/c it is and anti-knock additive so engine never needs to pull timing b/c engine willl not ping/knock with toulene in the tank. hope that helps
 
#5 ·
True Toluene is used as an octane booster, but proper useage requires Toluene to be heated for proper atomization - something that is definately not recommended as DIY.

Also, be VERY careful with Toluene handling/inhaling etc. it is a known to cause tremors, cancer and a whole whack of other non-nice symptoms.
 
#6 ·
It is pointless to run higher octane fuel on your car.

I made 390whp 405wtq on my Supra using 93 octane fuel on 18PSI. By using 104 octane I was able to raise the PSI to 21 thus making 434whp and 451wtq. I did not make more power by just simply adding the race fuel....the higher octane simply allowed me to raise the PSI and not cause my engine to detonate.

I would also stay far away from leaded fuel on your car!! You will destroy all types of O2 sensors and cats. My Supra is straightpiped so I have no worries running leaded even though I always run unleaded 104.
 
#7 ·
Umm... Higher octane does not equal more power. EtOH (booze) is 120 octane. Octane measures anti-knock properties, not power. In fact, higher the octane, the less combustable it is. I can put my cigarette out in EtOH, but not in gasoline. Don't use leaded gasoline in an unleaded car--the catalytic converter will melt and can cause fires (the chemical reaction releases more energy).
 
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