sorry, but octane doesn't mean anything unless you are driving to the max of the engine capacity. any octane will be just fine unless you are redlining the engine....it would matter then but who amoungst us redlines the engine? I don't, 87 vs 91? come on, that's trivial and the computer would compensate for that anyway....that's all tripe.....It's to make peope who drive BMWs and Mercedes and so forth think they have this really high performance engine that must have to have this fuel to make it perform up to these standards...pure hogwash....believe me, pure marketing. Not only that, but German octane is different than US ratings.....

Tell you what, my brother flies airplanes (Cesnas and little guys like that there)...I took him to Palwaukee Airport in Illinois to fly back to Minneapolis and he fueled the plane up with 103 octane aviation fuel and I snuck a half of tank of this non-taxed fuel into my BMW. All it did was make the engine run hotter, no performance increase at all, in a non-catalytic 1976 BMW 2002. That was my first clue as to the game.....it's all bull....has nothing to do with anything but ego, there are these things called knock sensors that will compensate for fuel value and they are calibrated for the lower octane fuel as a matter of course. MB and BMW and so forth expect you, as the average owner to not put premium in and have hence programmed the ECU for that. That's why if you 'chip' an ECU you MUST put premo in or that'll really screw things up. The car is dumbed down for the average driver/owner....it's true

You really don't have a clue...believe what you want.
Helps to wear a tin foil hat.

__________________
http://i19.photobucket.com/albums/b1...c/GOWIDE-1.jpg
1971 280SL ROADSTER
1988 300CE TWIN TURBO WIDEBODY
1994 E320 CABRIOLET
1999 C43 AMG
2005 G55K AMG
2008 CLK63 AMG BLACK SERIES

There's no reason here to apologize in advance for prevarication. It is your inalienable right.

Thanks for hijacking my thread, Cliffmac.

I was TRYING to get a discussion on ethanol versus mileage and instead we have drifted off into yet another case of you bashing of high-octane fuel.

Not only are most of your assertions incorrect, but they're irresponsible. Luckily there are plenty of people here to point out your folly lest somebody actually take a notion to follow your advice.

Plus, those "things called knock sensors" as you so eloquently put it only appear on newer cars. My '90 300SE doesn't have one, and I doubt the '79 BMW does either. In any case, the result of a detected knock is the computer retarding ignition timing in order to curb the detonation. In order for it to work, you have to make your car detonate first! In other words, all it does is try to stop damage all ready in progress. If that concept makes you happy running low octane fuel, then cheers!

I dare you to DOCUMENT the fuel you've been running and present it when you try to sell the car.

Normally I don't like to go off on other contributers here, but you've stolen my thread and filled it with off-topic disinformation.

If you really like to flame bait, start a thread of your own. Last time I looked it was free.

"MB and BMW and so forth expect you, as the average owner to not put premium in ....."

Right. That's why it says PREMIUM FUEL ONLY on the instrument cluster. You're a genius.


-tp

Now their you go i love it when a smarter than you goes and puts a fuel that uses an anti freeze in his car because he thinks he knows better than anyone else BTW the cats on t beener are pricy and when next month they clog and you have no power > the reason you have heard the car runs hotter < car is on the floor and only going 50 MPH - airplane fuel is for thin air at - 30* but you knew that i guess -- jz