For the last month or so I have been seriously considering trading in my 84 380SE (98,000 miles) for a Diesel.

Primary reason for thinking of trading in (I can keep only 1 car)was the fuel economy. So I did some back of the envelope calculations based on 20,000 miles per year. Here are the numbers:

For 380SE (at 19 mpg)...1053 gal/yr......$ 1,590.03 per yr ($ 1.51 per gal in FL)
For 300SDL( at 26mpg)...769 gal/yr.......$ 1,161.54 per yr ($ 1.51 per gal for Diesel too)

Savings per yr...$ 428.49 or a mere $ 35.71 per month.

Plus, with a Diesel, I would need to do synthetic oil changes (@ $ 4.00 per quart) and add additives (lube moly purge, water sequesterer etc) more frequently than what I do in the gas engine. This further brings down the savings.

The 380SE would last me till 250,000 miles too. The diesel perhaps a little more.

Looking solely from the savings viewpoint, there does not seem much of a point in trading in. Am I missing something ?

Thanks,

Amit