Spark gap change and fuel results... - PeachParts Mercedes-Benz Forum

LandYaghtLover · #1 10-17-2010, 08:46 PM

So I have been averaging 14.2 MPG in the city. Gap was apparently set to 0.045". Last weekend I removed the plugs, just to inspect, and was surprised by that gap. So I went to stock at 0.032". Economy average is not up to 18.6. Pretty happy with that

sptt · #2 10-17-2010, 11:20 PM

Somone had told me to gap my plugs at .045 on these older engines...I swear I got more gas mileage before (300 miles to a tank highway on a 300E) but poorer idle and starting performance. I put new plugs in and gapped them all to .032 and now I get great idle, about the same on high speed acceleration, but lucky to get 280 miles to a tank on same trips...any thoughts on this out there?

ps2cho · #3 10-18-2010, 01:11 AM

Stick to factory settings. Anything other than that will be compensating for something else!

sptt · #4 10-18-2010, 11:01 PM

Yes. I did and car has been running fine

I just got 300 miles out of my tank so I'm happy. About 20mpg highway.

Ferdman · #5 10-19-2010, 06:22 AM

sptt, a knowledgeable MB tech may recommend using a spark plug with a different heat range in a high mileage engine. Even so, the gap would be the same.