earossi |
09-08-2012 03:54 AM |
The reason there is a coupon discount on Mobil 1 may have to do with the fact that a lot of folks with performance cars are moving away from using Mobil 1. Since Mobil changed the formulation of its Mobil 1 synthetics about 5 years ago, there have been a rash of lubrication related failures in cars that use follower design cam shafts......such as the older Porsches (like our 993's). I found out about this the hard way when I experienced the first ever lubrication related failure of an engine part in all of the cars I have ever owned, including 8 Porsches.
When tearing down my motor to do a valve job, I was stunned to find that I had a galling related failure on one of my camshaft lobes. On researching it and talking to folks in the Porsche business, I found out that road use oils dropped the levels of ZDDP by about half when the EPA changed the regs requiring that catalytic converters last about twice as long as the old regs required (I don't remember the mileage requirements). At any rate, ZDDP apparently kills the ability of catalyst over time; so, the oil manufacturers reduced the level of ZDDP to accommodate the need for the cats to last longer. Unfortunately, ZDDP is the additive that enhances the ability of oil to cling to rotating parts. So, I have found that there is now a high incidence of lube related failures occurring.
Check the specs on Mobil 1 and you will see that the level of ZDDP is now down in the 700 ppm range. Prior to the new EPA regs, Mobil 1 carried ZDDP at levels in the 1300 to 1500 ppm range. Sorry for the bad tidings.
There are work arounds, but I didn't want to turn this thread into another oil discussion thread. Just do your research.
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