biker349

i have a 2004 cl600 twin turbo and have been using shell 93 octane ethanol gas, the shell station is also selling 90 octane pure gas. they say both have the same additives, except for the ethanol. is there any advantage, or benefit in using one over the other. the pure gas is about 10 cents a gallon more expensive. what are you opinions? this is my daily driver and i don't race.
thanks

BlownV8

I would not advise using the 90 on your turbocharged CL. It does not have the needed octane rating/ knock resistance to protect your engine.

Rainers

Read your owners Manual. If it say 90 then 90 will do.

Dr Matt

I run 90 in my modded CL65 about 350 days per year (other days are on MS109). I am at WOT at some point almost every day, in temperatures ranging from 80's to -20's Fahrenheit. Only days my car is not in boost is when all my driving is on ice and there is no pavement on a drive. Running 90 in a CL is fine, you just have less performance. The computer will compensate just fine. If your CL was not set up for ethanol, I'd be more worried about the corrosive effects of Alcohol than the lower octane fuel.

BlownV8

It says 91 is the minimum.

biker349

thanks for the responses. aren't all 2000+ cl's and mercedes set up to run on ethanol? pretty much except for rare cases like this one shell station that's all you can find.

BlownV8

There are only a hand full of C class cars that are flex fuel compatible. No, they are not good with full ethanol.

biker349

thanks, i'm talking about the standard 10% ethanol at the pump.

BlownV8

Yes, they will all work with 10% ethanol just fine.

Audi Junkie

Ethanol is your friend.

Geraldius

Indeed!