"It was the best of times, it was the worst of times." It sounds to me like Dickens owned two diesel Mercedes...

I've got the best of things and the worst of things: a 300D and a 300TD to compare to each other. Consequently, I'm perplexed at the differences in performance between these two cars.

Lilly, the 300D (265,000mi) , has real 'get-up-and-go,' she pulls well with her a/c on and gets 21-23 in the city and 24+ on the highway. I know that her timing chain has approximately 5°-6° of elongation and that at some point in her past, the IP was moved (probably to correct some lost performance issue) but, I do not know how much 'adjustment' was made.

OTOH, the lovely and charming Marlene, has always been 'stately' in her departure from traffic lights and can barely get out of her own way with the a/c running. Her economy is similar but she will occasionally pull a highway stint at 26-27mpg. Her cam timing is spot on (with a 4° offset key) and her IP has been adjusted accordingly but not checked by either drip timing or any other method.

I've always attributed these differences in performance and economy to different final drive ratios. I'd heard at some point that the wagon had a higher final drive than the sedan (2.88 as opposed to 3.07 or 3.56) and my experience in comparing the speed to the tach on the two cars seemed to bear this out. However, when we got TO's '85 wagon on the road, I discovered that it performed almost exactly like SWMBO's sedan which got me thinking that maybe Marlene wasn't living up to her part of the deal.

Then, one day I finally remembered to look at the final drive ratio stamp on the differential. Guess what? Both Marlene and Lilly have the same ratio: 3.07:1.

There just isn't that much difference in the weight of these two cars to account for the significant difference in performance.

What else could it be? All the usual stuff has been done: filters, oil change, throttle linkage etc...

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Never a dull moment at Berry Hill Farm.