wear on what? when you pull apart a stock engine, everything thats in oil usually looks new, its the stuff thats not in oil that wears out....

interesting, that's a big diff from 20w40

most engines run 5w20 for faster oil pressure on startup

gee bill call me daft but i will take all the anti wear i can get in my engine. and you are free to run reformulated EPA oil.



there are numerous areas that need anti wear. stationary gears for instance. if you happen to be running a turbo you should be highly concerned as to the CHRA thrust surfaces, i found that the 270 degree thrust bearings didn't cut it on my turbos. i now run the 360 thrust face, that's how critical wear is on a turbo'd rotary. antiwear will be a big help to the turbo CHRA thrust bearings. if you are perchance running a ball bearing turbo you know that ball bearings, unlike journal bearings contact the retaining surface directly and as such will greatly benefit from antiwear. of course there are other key areas like the apex seal to groove, the important metal/metal corner seal to side seal. i could go on, think oilpump thrust surfaces and gears.



the rotary needs all the antiwear it can get. after spending a bit more time on this i have concluded i will continue to run my 5-30 Mobil One and add 4 ounces of GM camshaft and lifter prelube part number 12345501 at your local GM dealer about $6.



reformulate reformulated oil.



howard coleman

OK. You are daft, but hey if you want to take a premium oil not recommended by mazda and increase the cost of lube changes withsomething not recommended by mazda and with no data on how it gums up the apex seals go for it. I don't run a turbo so have made no detailed tribological studies. But the article you quoted didn't mention a large increase in failures of turbos in service, so it might be fair to assume there is not a problem.



At the end of the day the RX8 engine had to undergo full US approvals with the oils available. It passed, albeit with some issues on catalytic converter life and fuelling to try and extend this, but pass it did.



The questions then are still:

1. which parts of the engine wear like a cam/rocker

2. If there is a problem how did mazda fix it for the RX8

the wear/lubrication regimes in a rotary arent really that bad. Camshafts tend to be worse than most other components, especially in high performance engingines because of the very high hertzian contact stress which is governed by the cam lobe and follower radii. If you want the best protection run a racing 2stroke oil, (which will not nessesarily be rated). If you plain bearing turbo ever needs EP addatives the bearings will already be stuffed. Also not mentioned is that the EP addatives are corrosive which can acutally cause bearings to fail earlyer than if a non EP oil was used