VW Dealers strongly recommend not to use the Bosch Platinum Plus 4 plugs on my 99 Jetta GLS and preferred the NGK plugs which i believe are more compatible to the Toyotas or Hondas. They never gave me a straight answer why the preference.
Can’t say what their reasons are, maybe has something to do with waste spark in your motor or the use of resistance plugs. I can tell you that my Mercedes flat won’t run with plats, and that NGK copper plugs make it purr.
simply that Bosch plugs are inferior, and they know it. And the addition of a bunch of electrodes simply INTERFERS with the flame front as gas ignites. YOu cannot beat and NGK plug…I had a BMW dealer tell me that just because it was German made (the plug) didn’t mean it was any good.
The Plus 4 plugs are more profitable for the dealer. That’s why they recommend them.
Use any of the plugs recommended in the owner’s manual. Don’t use other substitutes. That should take care of it. Dealers are generally far more concerned with their profit than your car.
Those are gimmick plugs. Equivalent to the Split-Fire plugs. They are NOT better…in fact they are NOT as good. NGK make EXCELLENT plugs. Use what ever plug is recommended in your owners manual. For a VW…Probably Bosch (Regular plugs).
I’ve had bad luck with normal Bosch plugs, and know of some others that have as well. Because of that, I stay away from Bosch plugs.