Originally Posted by elp_jc
Turbo lag is more of a problem the smaller the engine and higher the revs. With a relatively low revving 4.4L (and above) V8, it's hardly an issue. On a 2L I4 is a different story.
I disagree. Lag is lag. Sure lag can be minimized with smaller turbos on a larger engine, variable vane geometry (or other more exotic techniques) or worsened with larger turbos on a smaller engine, however, you can always feel the delay in throttle response and that is the lag. It hurts performance and feel and may need driving adjustments to fully work around it when driving at a 9/10 or 10/10 pace. Also, as pointed out above the turbo lag on the M5 has been reported as quite noticeable.