Originally Posted by manny

We have a winner!
M-B Dude is a close second.
It is all primarily about waste oil reduction.
Something like 2 million gallons of waste oil produced in North America every day, with most of it coming from vehicle oilchanges.
Also, as M-B Dude pointed out, it involves " peer-pressure " amongst the vehicle manufacturers.
Same as going to 100 k miles sparkplug change intervals.
( Good luck trying to get a plug out of an aluminum head in 100 k miles ).
Know anybody that has a vehicle where it takes 2.5 hours to change plugs, at $ 90.00 per hour?
The manufacturers argument " Well, what are you *****ing about, it only needs to be done every 100 k miles "?