What can happen to the C230 Kompressor engine if you don't use premium gas?

Answer 1

Not just loss of performance, which may well make cause more use and problems than any gas cost savings...but in todays world of so many computer controlled things...lord knows exactly what else.

Yes, using a grade of fuel that is higher than specified probably doesn't improve anything....but, this car is designed and engineered for the premium grade...and obviously if they could have made it work well enough with a lower grade...they would have. (Having to sell it with a premium grade requirement wasn't a good feature or something MB would want to do - it was widely noted and hurt sales!) As an owner of a C230 k, maybe I can answer your question. In a kompressor engine the supercharger forces more air mass in the cylinders to increase the output power. The increase in pressure also increase intake air temperature. The intercooler will reduce the intake air temperature up to a limit (depending on ambient temperature). The whole process is equivalent to increase the engine compression ratio and the engine will need higher octane (premium) fuel. If you use low octane fuel the engine can detonate. Since long term detonation can damage or destroy engine internal parts (pistons, rods, bearings, crankshaft and so on) modern computer controlled engines incorporate electronic detonation control. The ecu will control (reduce) detonation by retarding ignition timing and/or increasing fuel/air ratio until detonation stops. In other words, when the engine detonates it will have less power, will consume more fuel (good bye economy) and will have increased internal stress. You can avoid all this by using the recommended fuel. Your engine will perform better and last longer. MB recommends to limit both operating time and loading in your engine if you can't get premium fuel.