Can u guys tell me what's the correct spark plug brand and number to use on my 1988 300CE(103 Engine)? I'm in a very hot climate that during summer time temps can reach anywhere between 42C-45C!!

The original spark plugs were Bosch H9DC. I would recommend going with Bosch H9DCO, which are essentially the same, except heavy duty center electrode. The DCO version became the standard plug in August 1988. They can be used interchangeably.

Gilly

Thanks for the reply. I'll go ahead and try those on.

Installed a set of Champion platinum plugs 100,000 miles ago. They work just like the OEM plugs that came with the car I bought new. Keep in mind that MB 's do not require a lot, if any, maintenace. They just seem to go forever with little attention. Good luck. and remember KISS.