Explain this 1973/450sl
 

I had my car tuned-up last year and she ran pretty good but is still a gas hog
6-8 mpg in city. i decided to look at the plugs and I found the following plugs
on the car, w8dco, wr9dpx,w8dc,w9dc and w7dc. I replaced all of the plugs with Champion plugs yuk-yuk the car sounded yuk-yuk. I then replaced the plugs with some used Bosch supers Ihad laying around. The car is not sounding happy nor am I.
Can someone explain how the spark plug mixture could work. I also noticed my ignition cables shielded end to the plug is marked 1 ohm. I thouht platinum plugs were a no-no thanks

"6-8 mpg" at $3.50 a gallon means you pay $0.50 for every mile. How much do you spend monthly on gas ?

My car makes 20mpg and I am spending around 200 bucks already.

explain this 1973 450sl
 

The car is not a daily driver . She is strictly for leisurly drives. I am loking to get her running right. Time to go to new indie.

Have your indy do a smoke test look for vacuum leaks,do a resistance check on all wires,see how high they are.Call Phill and get the proper plugs.Have your indy check the EHA and potentiometer,do the fuel testing of upper and lower chambers,check the on off ratio at x11.all can be found on a search.JNT

explain this 1973/450sl
 

I thanks for the suggestion for a smoke test. I don't believe my car has an EHA, but I'll ask,by the way what is it? Is there a tool I can check the condiuctivity of the wires with? I quess this will teach me to leave what isn't broke alone! Thanks!