On paper, the horsepower figure of the XR8 GTS means it should have a good chance against the E63. It does have a glaring weakness with its 6-speed manual versus the quick and consistent Mercedes MCT automatic. It does have a slight advantage in curb weight coming it at roughly 200 pounds less than the E63.
So what happens? The E63 AMG makes easy work of it. Both cars are rear wheel drive as this is not the 4Matic E63 AMG and it is also the standard version and not the more powerful S version. Regardless, the result is the AMG covering the kilometer in 21.88 seconds and the Vauxhall 22.45 seconds.
EVO plays the difference off as if it is minimal but it isn't. It also is not simply a matter of gearboxes as the M157 turbo punch would not be mitigated by giving the VXR8 the same transmission. Since these are Brits and they do not know how to drag race they did not include trap speeds at the kilometer marker. If they did, we would likely see the E63 AMG pulling much, much harder at that point. Regardless, the Vauxhall is 20,000 British Pounds cheaper than the E63. It also definitely looks like it is.