Until recently, my 1988 260E rarely hovered above 80 degrees on the temp
gauge.

But in recent months, I've noticed it pick up to 85, 95 when the car has
been sitting in traffic. It cools right down once I'm cruising again.

I recently had the car serviced at a new place and I'm wondering if they are
using a different type of coolant. The regular mechanic (now gone) was a bit
of a fanatic on complying with what Mercedes recommended so perhaps a
standard non-Mercedes coolant is being used.

Would that make any difference. What else could be causing the additional
heat?

By the way I'm in Sydney, Australia. It's summer and yes it's hot. But that
shouldn't a factor to push the temp up to this level.

Thanks