The diesel engines Volkswagon used I felt where built under license from Mercedes. Just a suspicion.

The natural aspired ones where slow. Starting in 1985 they sold the same size engine with a turbo. For whatever reason they continued selling the Natural aspired ones as well into the 1990s. Installing higher gear ratios in the transmissions to give them a little more acceleration eventually. Personally I never liked that attempt.

The turbo versions did much better and they at least equaled the fuel millage of the Normal diesel engine. Volkswagon had an interesting formula. The total parts count for the vehicle was very low,

Easy and cheap to repair. Perhaps one of the more durable cars of that time. The best years we found where the 1985s and 86s .

Unfortunatly they would not self start reliably in really cold weather. You had to resort to the block heaters.