i have "played" with several car in my time, both with 3.1 engine, and 2.8 installed! i have found that 4wd drive cars, although mainly devestating away from the line, are not much quicker in the mid-reange or top end than a well sorted vr. speedo reading will always tell a story but comparatively speaking, if you work on standard performance figures across the board, the vr does seem to endow itself with more performance than is quoted, especially when tuned!