attention to the monitor, and it called for an oil change after 17,000 miles.
There is no oil dipstick. What are your thoughts on a 17,000-mile drain
interval? Thanks.

Leon—Phoenix,   Arizona

Leon,

A High-performance 5W20 synthetic motor oil as specified by BMW is

used in this engine. The oil life monitor measures engine operating
environment with a computer algorithm to accurately calculate serviceable
engine oil life. So, in answer to your question, since you’re using synthetic
oil specified by BMW and following the oil life monitor dictates, I have no
problem with this drain interval

Tom

Dear    Tom,

Q I own a 2000 Lexus ES 300 Platinum Series. I purchased the auto three

and a half years ago, and it had only 4,400 miles on it. An elderly man who
owned the car was the original owner. I now have nearly 39,000 miles on the
car and it appears to be running fine (the Lexus dealership has never
indicated any problem). However, I wonder if there might have been sludge
buildup when the car sat idle during its previous ownership and, if so, could
this cause trouble later on? Would it be evident by now?

Sandra—Hollywood,   California

Sandra,

A Sludge buildup is not a result of a car “sitting.” Sludge will build up

when oil is left in the crankcase for extended periods of time and the vehicle
is operated without changing the oil according to manufacturer’s specs.
Excessive heat from friction (which is caused by oil that has lost its
lubricating property) causes oxidation; the combination of oxidation and
excessive heat causes sludge, an oily cake-like substance that soaks up oil
and causes lack of lubrication. Keep the oil changed according to
manufacturer’s specs and you should not have a problem.