"Pete C." wrote in message
ster.com...

Van Chocstraw wrote:

RickH wrote:
I went to the Jiffy Lube this weekend and thought I'd splurge and put
in some Castrol Syntec as they were having a sale on it, (vehicle 2007
Toyota RAV4). When I asked for the Syntec the guy said that once you
go to a synthetic oil, you should stay on it and not go back to
regular oil. Well since the the regular cost of a Syntec oil change
is double, I said forget it and just put in regular oil.

First, is it true what the guy said about it being "bad" to go back to
regular oil after using synthetic? If so, why? I had a car in early
the 90's that loved Mobile 1, ran great on it, I dont remember
dedicating that car to Mobile 1 though for all time, I'm sure I used
all different oils.

Thanks
Rick

Synthetics just give you a longer time between oil changes. If you go
back to regular you change more often. Jetta Diesels specify synthetic
for longevity and fewer oil changes. VW also pays for the first 3 or 4
oil changes.

Synthetics are particularly helpful for engines with turbos as the
synthetics have higher temperature tolerance and resistance to "cooking"
in the turbo bearings after you shut the engine off.

some cars require synthetic. for example, corvettes starting in the late 80s
required moble 1 or equivalent.