Proper spark plug gap
 

Hello,
I have a 1973 280sel 4.5 and I am putting in new Bosch W7DC plugs. Is the proper gap .032"? (That's the recommendation at the Bosch website.) My owners manual says .024". Thanks -Mike

These threads make mention of the W7DC plug:

http://www.peachparts.com/shopforum/search.php?action=showresults&searchid=757187&sortby=lastpost&sortorder=descending

The owners manual may be hard to argue with though. I don't understand the difference between it and the Bosch site? Perhaps Bosch was providing a "catch-all" gap that covered many autos using W7DC?

Newer electronic models often times idle better with a wider gap. If yours is a points & condenser setup, you might not want to venture too far off the factory recommendation.

My 2 cents.

Michael

European cars, historically ( 1960's 70's & 80's, before electronic ignition ) have always had very small plug gaps.
If you look at plug gaps for BMW, Mercedes, Porsche, Audi, VW, etc., this has always been the case.
For your 1973 model, I would be inclined to either go with the manual specified 0.024" or, you could try a compromise of both, & go in the middle with 0.028".
You will know if your car can't handle the wider gap, as you would experience a " tip-in" misfire on new plugs, in fairly short order. ;)