I have a 1988 300SEL. No, it is not very fast, but with 177hp, it is not that slow either.

My reason for buying the 300 was the simplicity of the six cylinder. I have also not driven the 420 or 560. On the highway the car is really smooth and the high rpm does not add any additional noise in the car. It is very quiet at 60 to 70 mph - very close to my E350!

Condition and updated maintenance is for me more important than the engine size. My SEL was a Southern CA car, and I am the second owner but had NO service records. The car is not perfect, but I have NO rust anywhere and inside everything is still original and in good condition with only 100k miles on the clock.

The head gasket is still the original, and although I have small oil leaks, they are small and I don't have to add oil between changes (~5k miles between changes). Most of the repairs was due to the car not being driven enough. From all the stuff I found in the car, the car did about 2k miles in the last 10 years before I bought the car - the tires were also over 10 years old. Now that it is driven every few days, it is a real pleasure to drive.

Good luck!

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2012 Mercedes E350
1988 Mercedes 300SEL
1996 Nissan Pickup
2003 BMW K1200GT