1992 525i

Platinum or not? Brands, number of tips, etc.

Thank you in advance,
Ron

I just installed a set of Bosch Plat+4 (4417) in my 98 M3/2. The original plugs I pulled out had 24K miles on them and still looked OK.

Maybe it was my imagination, but the idle seemed smoother and RPMs seems to happen faster.

Make sure to use a thin coating of anti-sieze compound on the plug threads (a small toothbrush works great) and then torque the plugs to the spec on the plug box (usually 19 ftlbs). This is very important in BMW aluminum heads. Stripping the threads means a very expensive trip to the dealer. Not tight enough means the cylinder pressure will push the plug out and strip the threads. Don't install these plugs without a torque wrench.

Ken