Yesterday, the 'Check Engine' message came up in the dash computer of my 2005 Mercedes C230 Kompressor during hard acceleration. I immediatly thought a line might be pinched in the EGR system, but then the engine sputtered and hesitated. I pulled over, turned off the engine for a couple minutes, then restarted. The engine seemed to run smoothly, but I babyed it straight to the dealer and left it with them to check it out. The service manager called to say he would have to keep it over night because he had to order injectors. Injectors! The car only has 8200 miles on it!

Now here's what he says that I'm unsure about. He questioned the quality of the fuel I'd been using. I told him that I had only ever used 1 type of gasoline in the car: BP 93 octane (BP now sells Amoco Fuels, which I have heard is some of the cleanest gas you can buy). He then said that I should be using a lower octane fuel. Like 87 octane or 'regular' unleaded. This is in direct contradiction with the owners' manual. He said that the fuel in the US is so much purer than the fuel in Europe that we don't always need the highest octane, especially in the warmer areas of the country. He said that the high-octane gas is burning too quickly and a residue is building up on my injectors (especially the #4 injector).

OK, I thought higher octane made the gas burn slower to prevent knocking in the colder weather, not faster. And what about his recommendation vis-a-vis my warranty. Manual says 91 Octane and above, he says 87 is OK. He said something about a service bulletin on this topic, which I will ask for a copy of, but what do you guys think? Does thic sound right to you?

__________________
--Craig.

"When you see a fork in the road, take it!"
(Yogi Berra)