The Z4M is a very capable car but almost every publication will tell you it is a handful to get a best lap out of it. That is why they often call it German Viper. The Z4M is overall a better performance machine then 335i coupe any day. The problem is to extract that extra performance from it with ease. On the other hand the 335i is more easier to drive on track and not the outright better performance machine.
Also, I recall that Z4M in North American market were released with very poor tire choice by BMW. It was a very well known fact among Z4M owners. That poor tire choice could have also caused slower times by causing understeer/oversteer issues and eroding confidence of the driver. The Z4M the BMW itself tested had PS2 as a tire choice then those Continental or Pilot sports.
Also, both the track are similar but not identical. The Nurburgring still has overall higher avg. top speeds sections then the VIR. Anyways, Z4M is very capable car which is best in the hands of a very experienced driver who is not afraid to extract every ounce of performance from it. Also, in order to do it the Z4M has to be wearing proper rubber otherwise it will be a long day no matter who drives it.
The C&D test is not word of god but just one of many tests. Here are some more times that go to show that the Z4M and 335i coupe times are very close to one another and depending on who is the driver, weather conditions, track or tire choices all can effect an out come.
Track 335i Coupe Z4 M Coupe
Hockenheim Short 1:17.80 1:17.20 (small advantage Z4M)
Balocco 3:02.49 2:56.67 (small advantage Z4M)
Serres Racing Circuit 1:35.25 1:36.20 (small advantage 335i)
Originally Posted by Daemonblitz
If VIR is a type of track that is close to Nurburgring then something doesn't add up here, this is what i was talking about in my earlier post.
Nurburgring lap times for some BMWs:
8:05 BMW M3 E92
8:09 BMW M6 E63 (w/ sport tires)
8:12 BMW 1 series M Coupe
8:12 BMW Z4 M Coupe
8:13 BMW M5 E60
8:22 BMW M3 E46
8:26 BMW 335i E92 Coupe