The 300D is just a turbodiesel engine in the same chassis as a 300E, so length and width are the same.

The '87 300D has a 6-cylinder 3.0-liter turbodiesel engine.

I don't know for sure but suspect the AC is the same on the two models. My '87 300D had an expensive conversion to R134 just before I bought it. I think the car had developed into a money pit for the previous owner, and he dumped it. The dealer told him he needed a new head - actually it needed one new glow plug for $10. I lucked out......

Oil change is relatively easy. The capacity is about two gallons. The oil filter is a cannister type that is a little messy, but easy to get to. Transmissions are just about the same on the two models as far as the way the fluid and filters are changed.

The '90-'93 300D has a 5-cylinder 2.5-liter turbocharged engine.

Ken300D