[WeekendWarriorz]

Originally Posted by XMetal

Having too much zinc isn't a great thing either...Your cats would have a shorten life if too much of it gets into the combustion chamber. That's why a lot of "Race" oils that have lots of zinc have a "off road use only" label, meaning that you should run it without cats.

Believe what you want to believe, but I'm a data-minded person - show me data to prove it. If Liqui Moly can provide only 2ppm of lead wear after my rod bearing change, why would I need to look elsewhere?

Regarding that 175k miles M3 - I would be a believer if he pull the bearings and show no copper. Just because the car is still running doesn't mean that it won't throw a rod at any moment.

I mean are we really going to worry about the life of your cats? They're going to come off anyways...

I'm just going with the data that I've seen and the real world experience of other people. Again, 700+ built engines ranging from stock, stroker, and supercharged s54/s65/s85/s63tu's over multiple years and miles of racing that he's built and not one failure from rod bearings is enough for me to make a change. It's all personal preference to what you're comfortable running. But facts aside, 10w60 will cause your rod bearings to fail sooner or later. My car is at 53k miles and I'll be running redline 5w50 for the rest of its life, so if it fails I'll post my results. I probably will change the rod bearings as well when I get a blower on it with treated bearings for a piece of mind so I can see what type of wear (if any or a lot) there is with running 5w50.