Lynzoid

Except GM cars (including Saab)... GM still unable to make reliable coils (including coil-on-plugs). I had 2 gm cars which had coil failure every year almost. And my friend have a saab, that had it's CoP cartridge fail in first 12 months....

warminwisc

When you check carfax on Audi A8 and A6 you see replace coils mentioned at even 50-60 k. I have 145k on my plugs no loss of anything, devils advocate why should I change em now if the system is so efficient?