Ethional What's it going to do to our Cars - PeachParts Mercedes-Benz Forum

nh500sl · #1 04-21-2008, 11:01 AM

I see no logic to running ethional, unfortunitly, it is now required in oregon. I'm conceared about how my 1983 Mercedes 500SL is going to handle this, as well as my older volvo 240s and my 1983 BMW 633 CSI. Is there an addiditve that I should run to combate this less effective fuel or? My mechanic said he has done 3 head gaskets this year and he a Volvos only shop and said something is going on. So, I'm concearned. Thanks.

Mistress · #2 04-21-2008, 11:20 AM

I'm not wondering if there isn't something we can add to the fuel that will counter this? You might want to put this on the tech side and see what comes up.

PaulC · #3 04-21-2008, 11:22 AM

Doesn't ethanol actually have a higher octane rating than gasoline? If your mechanic is implying head gasket issues due to pre-ignition, I'm not sure that he's on the right track. Are premium-grade fuels (over 89 octane) blended with ethanol?

Knightrider966 · #4 04-21-2008, 11:59 AM

Are you talking about E85 or a smaller blend? We have been using Ethanol blends since the 1970's with no problems and cleaner emissions. It would help to know the blend you are referring to.

Dee8go · #5 04-21-2008, 12:05 PM

I generally buy Exxon Premium gas, which I believe contains ethanol. Actually, I never really gave it much thought. Why would that hurt your engine and how would it do so?

PaulC · #6 04-21-2008, 12:19 PM

Perhaps the mechanic is surmising that the ethanol is causing a chemical reaction with the head gasket material.

Graplr · #7 04-21-2008, 12:22 PM

All Minnesota gasoline is E10 (ethanol 10%, gasoline 90%) and I don't recall when it goes into effect (it may have already) but it will (or is) E20.

I haven't heard of any issues because of it.

KarTek · #8 04-21-2008, 01:09 PM

I believe it degrades the plastic bits in the fuel system but I think that was mostly carburated vehicles and gnerally on cars made in the '70's.

Narcoleptic · #9 04-21-2008, 01:48 PM

Nissan had problems with mid to late '80s 3.0L V-6s when ethanol was first introduced. They had to replace the fuel injector seals on those engines.

Graplr · #10 04-21-2008, 01:50 PM

Quote:

Originally Posted by PaulC

Doesn't ethanol actually have a higher octane rating than gasoline?

Yes, it does have a high octane rating. I believe (don't quote me though, just of the top of my head) it is around 95 octane.

Emmerich · #11 04-21-2008, 02:10 PM

It doesn't matter what the octane rating of ethanol is, it is diluted so what you buy is 87, 89, or 92 or whatever it says on the pump.

Ethanol is an oxygenator, it is being mandated as a replacement for MTBE. It will run about 10% leaner. Cars with modern computers will compensate. Older cars can't. My 6.9 (CIS) runs like crap on it.

300EVIL · #12 04-21-2008, 02:10 PM

Quote:

Originally Posted by Graplr

Yes, it does have a high octane rating. I believe (don't quote me though, just of the top of my head) it is around 95 octane.

E85 has an octane rating of 100 to 105. Just richen the mixture a bit, advance your timing a little and you should be able to make the same power you did with gasoline. I'm looking forward to E85 in my area.

irish_flu · #13 04-21-2008, 05:19 PM

Quote:

Originally Posted by 300EVIL

E85 has an octane rating of 100 to 105. Just richen the mixture a bit, advance your timing a little and you should be able to make the same power you did with gasoline. I'm looking forward to E85 in my area.

Thanks, that's good to know. The owner's manual for my Saab (which is always quick to imply that you're a wuss and should "just do it"; there are also many pictures which involve moose) actually says it's cool with Ethanol.

I'm happy to know I can quickly make my other rides like it too.

aklim · #14 04-21-2008, 05:32 PM

Quote:

Originally Posted by 300EVIL

E85 has an octane rating of 100 to 105. Just richen the mixture a bit, advance your timing a little and you should be able to make the same power you did with gasoline. I'm looking forward to E85 in my area.

How? Even if you could easily advance timing, all you could do is make it go throughout the curve instead of at the correct points. Besides, what good is octane when you BTU is less? I do know in the Flex fuel cars, you would have to have bigger fuel pumps and injectors because you need more fuel to make up for the lack of BTU.

300EVIL · #15 04-21-2008, 07:42 PM

Quote:

Originally Posted by aklim

How? Even if you could easily advance timing, all you could do is make it go throughout the curve instead of at the correct points. Besides, what good is octane when you BTU is less? I do know in the Flex fuel cars, you would have to have bigger fuel pumps and injectors because you need more fuel to make up for the lack of BTU.

It's just a statement, I never said it would be easy. It would be best to have the timing controlled by a programmable controller to get the optimum ignition timing for running ethanol. Your right about the BTU, even at a stoichiometric mixture for both fuels, gasoline is going to be the winner. However, due to the higher octane of ethanol, you would be able to compensate for losses by advancing the ignition timing and/or increasing compression. Ethanol also burns cooler than gasoline so that's another plus for E85. I believe forced induction engines will greatly benefit from the availability of E85 due to it's unique property's over gasoline.