Details for CLICK & CLACK

Dear Car Talk:
I’m retired, and at
crisis and bought my
first Mercedes (new).
But being retired and
living downtown in
the city where I can
walk to most things,
I find myself doing
city driving almost
all the time. So is it
necessary to get on
the freeway once in
a while to keep the
car engine in good
shape? If so, how frequent and how far as
a minimum? I enjoy
your column!
-- Jim
Dear Jim:
No, there’s no need
to drive your car on
the highway, Jim.
People used to tell
you to take your car
out on the highway
and “blow out the carbon.” But there is no
more carbon. Modern
engines with fuel injection, computerized
engine controls and
run so cleanly now that
if you take your engine apart after 50,000
miles, the tops of your
pistons will be as clean
as they were when you
drove off the lot. So
doing only “in town”
driving is no problem.
And if you’re driving for at least 15 or 20
minutes on a semi-regular basis, you’re probably getting the exhaust
system hot enough to
evaporate most of wa-

Ray Magliozzi

can be reached by e-mail at the Car
Talk website at

ter vapor that condenses in there when the
exhaust system is cold.
If you take all fiveminute trips, you could
cause your exhaust system to corrode prematurely. An exhaust system on this car could
run you a few mortgage payments. On the
other hand, the exhaust system on a Mercedes is pretty robust.
So even with all those
short trips, corroding the exhaust might
take 10 years. And by
then, your ne’er-dowell son probably will
have talked you out of
this car, and you’ll be
driving a 2028 S-Class.
And we can let him
replace the exhaust.
Enjoy your car, and
don’t worry about
it, Jim.
Got a question about
cars? Write to Ray in care
of King Features, 628 Virginia Drive, Orlando, FL
32803, or email by visiting
the Car Talk website at
(c) 2018 by Ray Magliozzi
and Doug Berman
Distributed by King Features Syndicate, Inc.


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