Regarding stop and go, slow speed use in the context of severe service:
Few usage patterns would be more likely to fall in this category than
inner city delivery service. Fleet operators, unlike quickie oil change
establishments, dealer service departments, independant shops, DIY auto
supply stores. etc. have no incentive other than to operate and maintain
their fleets in the most cost effective manner. They have demonstrated that
it is not necessary to change oil at 3000 mile intervals to get reasonable
longevity from modern engines using modern fuels and oils. By reasonable
I mean engine life of at least 150,000 to 200,000 miles.




--
Better to be stuck up in a tree than tied to one.

Larry Wasserman - Baltimore Maryland - lwasserm(a)sdf. lonestar.org