I have been seeing these numbers for exceptional fuel mileage on all sorts of cars and most of it surprises me. Now, I would never have believed that the 90 300D 2.5 I used to have would get 34 mpg, but it did. However, I am genuinely surprised to hear about 123's getting such good mileage.
I have had 3 of them and the best I could ever get on them was 25 mpg on the highway. I guess mine were bad examples because the last one had nearly 500,000 miles on it. But, I just thought I would always get about 24 on the highway and I would get about 18-21 in town. Now that I am getting 20-21 on the highway, I can really appreciate getting 25 and would love to get 34 again. Donald H. Snook 1990 300SEL 134K
