My 300D Turbo Diesel doesn't seem to go faster than 70 mph. Though I know this is faster than most posted speed limits, this shouldn't be. The trans goes through all it's gears but it seems to rev very high. Naturally, the tach doesn't work. The turbo still works though, according to my mechanic and the pickup is OK for what it is, I don't know why the car has to work so hard to maintain highway speed.