In the several threads in the archives that had tons of opinions on these and other plugs, most everyone discredited the +4 plugs for these cars. They may work well for other types of cars with different ignition systems but the overall feeling is your wasting your money. ---------------------------------------------------- I tried them in my '84 633 sometime back and yes, it idled well enough. But it took longer to start and the car lost power. I switched back to the silbers and saw a big improvement. Just my opinion. If they work for you, go with it!