1. At the time I changed spark plugs, I did not have all of the knowledge contained in the thread. I had heard some opinions that the aftermarket Bosch plugs were not the same as the BMW-branded Bosch plugs, as well as some anecdotal evidence that the aftermarket Bosch plugs sometimes caused problems in some cars. So, for the less than $100 that would be saved on a component that appears to have at least a 10-year life, that $10/year just wasn't worth risking it. So far, the BMW-branded Bosch plugs run fine in my car.
Originally Posted by Swanicyouth
I read the post and I guess I'm wrong. From whats written it looks like the BMW and Pep Boys plugs are the same. Just curious, armed with that knowledge, why did you go for the dealer part at the heightened cost?
2. Although I have no doubt that someone at Bosch told Ron that the $20 BMW-branded Bosch plug and the $6 aftermarket Bosch plug are exactly the same, I don't know who that person was and I have not seen any documentation from Bosch of this "exactly the same", so my opinion is that the two plugs MAY be exactly the same, or they may not be exactly the same (equivalent and identical are not the same thing). Given that uncertainty, I would probably make the same decision today to use the BMW-branded Bosch (or NGK) plugs from the dealer. Since I have already replaced my plugs, I probably won't have to worry about it again for another 10 years. When it is time to replace my spark plugs again, I'll check the current state of knowledge about BMW vs. aftermarket spark plugs.
"That's right, you're not from Texas, but Texas wants you anyway." -LL
2001 Z3 3.0i Roadster (Topaz Blue Metallic, 5-speed manual, Sport Package, CD radio, heated seats and mirrors, non-power top via special order)
"Beemer" is for my BMW motorcycles - '13 K1300S, '95 R1100RS, '88 K75S, '75 R90S (gone, but not forgotten).