I own a 1991 300 SL. Fuel use is about 20 mpg 75% city, 25% freeway. On a long freeway trip I can get almost 26 mpg. I don't think the 500 SL does all that much worse. I like to work on the car myself and there is ample working room under the hood. The 300 SL has a 5 speed automatic as opposed to a 4 speed on the 500SL. Using all 5 gears, the 300SL is still about 2 seconds slower 0-60 than a 500 SL. But once you get the revs up, the 300SL is very responsive and pulls hard. The 300SL spins up to 6500 rpm's quickly and effortlessly. It's a lot of fun to drive. When looking at any older 129, open the doors, get down on the ground and look up at the underside of the door panel where the rubber weather seal is located. This is the only known place where this chassis rusts pre-maturely.

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