I'm trying to track down the source of the low-rpm vibrations in my 240D 3.0T and my dad (B.S. in Mech. Eng. and phD in Combustion from MIT, used to build and race cars) says they're from the engine lugging. Now, I don't understand why it would lug and higher speeds than the 616. He said it was cause of the turbo.

Now, since a smaller turbo should spool up faster, I imagine it would lug at lower speeds. Has anyone tried this? Or does anyone maybe have the shift points of a non-turbo 617 for comparison?

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1983 240D 3.0T 4-speed manual, now sold

1989 Subaru GL Wagon 5-speed Touring Edition