Fuel

[Scott 02]

I know running premium gas will not hurt your car, but what would happen if you ran just a little bit of racing fuel like Turbo Blue or CAM2 in your 3.8 V-6?? Just enough so you can smell it out the tail pipes. I do know if you run racing fuel straight in your stock motor it will hurt it bad. Only a stupid ass would do that. anyway, i was just thinking about 1/8 of a tank mixed with premium gas.

[Moppie]

Well race gas is generaly just leaded high octane petrol, running it in any engine won't harm it at all. Infact you may get a bit of extra power depending on the engine and fuel mix.

But what it can harm is the catylitic converters. The Lead in the fuel will rapidly clog the fine honey combe structure on the converter which of course is a bad thing.
If you dont have cats and its legal to run race gas and you can afford it then go for it.


But here in NZ its illegal to run race or aviation fuel in your car on the road because its leaded. (race gas is often made from old expired av gas, which as far as I know is still leaded, and will remain so for sometime as most planes require it)

[PWMAN]

Leaded gas also takes out 02 sensors

I've seen 97 octane unleaded pump gas.
You can't over-octane an engine, you can only under-octane causing knock/ping and detenation.

[Steel]

well, generally you want the lowest octane you can get away with. I know with my car that has really low compression, i'd lose power if i were to put 93 or 95 octane gaoline in. Plus lose money. 87 works fine, and i with they had like, 80 octane so i can throw that into my tank.

[Moppie]

Originally posted by Steel
well, generally you want the lowest octane you can get away with.

Please explain how that works? Because its sounds like a fairy tale to me.



As for leaded fuel doing bad things to O2 sensors?
I dont personaly believe it. I know of a lot of race cars with O2 sensors that run perfectly well on leaded Av gas and have no problems at all.
Infact I know of several factory standard cars which use O2 sensors as part of the engine mangament and require leaded fuel. The early SR20de powered SSS Sentra sold here in NZ is one example as the CA18 powered 180/200sx sold here and in Japan.
The few storys Iv heard about ruined O2 sensors have always had another better explanation for why the O2 sensor might have failed.

[castovicini]

The higher the octane number, the higher the cylinder pressurre and temperture can be with out exploding prematurely, pinging. Buying more octane than you need will only cost more money per mile unles:

If the octane booster is methanol or ethanol, those boosters remove water from the air and disolve it in the fuel system which will corrode it quickly. Pure methanol cars have stainless steel fuel systems.

If the Octane boost comes from ethyllead, that chemical will poison the catalsyt in in the exhaust system and the EPA can fine people $25,000 for puposely ruining the catalyst. Also, the catalyst will breakdown and eventuually cause bakepressure and loss of power.

The main reason you can't use aviation gas or other non-pumped fuels is.. The goverment hasn't collected taxes on it . A long time ago, the oil companies were required to color the gas once it was metered and the taxes were paid on it. Many of people ran free gasoline in the oil production areas of the US and the police could stop the car and check for the colorization to see it the state had collected it taxes.

The octane in gasoline used to been increased by addition of cyclohexanes, notabily benzene (104 Octane), but benezene is being reduced because of suspected links to cancer so the search goes on for the best fuels......