Hi all. Hopefully of interest to someone,, further to researching more on piston rings, and std rings,, having had the npr aftermarket ring set for some time, decided to pick up a new set of genuine bmw rings today just for comparison, in the 00 size,,,putting the rings side by side I don’t see much difference other than markings, same profiles etc ,,and I’d be happy to use the npr rings on a rebuild ,, Also I believe mahle don’t make the rings,just the pistons,, And apparently npr are the only aftermarket manufacturers to make the rings for the oem pistons
I could be completely wrong of course,, There is a very slight difference in front to back measurements of the npr , npr Only Supply the one size for public purchases,,. Bmw list Three sizes for different bore sizes. I’ve got measurements if anybody interested ,, The npr rings for the six sets cost me about £170. Genuine oem 00 size £115 one set,,
imo npr look a great buy especially for track car rebuild, or any std m3. Dare I say even the csl,, any feedback chaps welcome “”good or bad “”