Hello,

I have a 1988 300E W124 and I took it in for service the other day. My
mechanic lent me his 86 300E as a courtesy car. When I drove it, I realize
that my 88 300E is so much slower than my mechanic's 86. I bought the car
brand new back in 1988 and I guess my car is getting slower (slowly)
everyday, so I don't even notice that my car is so slow.

Specifically, the acceleration of my car from stop is so much slower than
his car. What could be wrong with my car? My car has 245,000 kms on it and
have never done a valve job yet. Could this be the problem? Or could one
or more of the cylinders doesn't have enough compression? I guess if this is the case, then the engine will vibrate like crazy, right? However, my engine is smooth as silk at all rpm's. What else could
be wrong?

Please advise. Thank you in advance.