then factor in age/mileage/condition/servicing/auto/manual/fuel used/blah blah blah weight etc and see.

the Xr8 was quicker than the xr6 across the board of models. The ticky 8 has better pull than the ticky 6. if it were a rolling start then the gap is a lot closer as the 6 is worked into where it has almost as much torque. The 8 just has a much thicker torque spread. Claimed figues was both 7.6 secs to 100, but I reckon the guy who did the 8 was on a bad day.

example
97 model (where the 6 had almost as much peak kw as the 8- Im giving the 6 the best shot)

XR6- 164kw @ 5000/ 366nm @ 3150/ 1527kg ( 4.17kg/nm @ peak)
XR8- 170kw @ 4500/ 402nm @ 3100/ 1567kg ( 3.89kg/nm @ peak)

therefore the 8 HAS to be faster off the mark all other factors equal.

but it isnt!!!
I have seen it first hand many times at willowbank. A big factor is the weight of the 8 cyl.
more weight = more power required to move it.
why otherwise would my ef 6 gli be quicker than an xr8? 15.9 vs 16.2

its just becuase the EF i6's are a world class engine compared to the v8. there efficient, tourqy and refiend...

here here... the ford 6 is better then the v8

agreed. the only e series xr8 that was quicker than the xr6 was the 185kw version. makes sense when you look at the technology of both. roller rockers and ohc compared to a motor that was basicaly the same since 1967. ford had to do something in 1997 to stop the v8 having egg on its face. hmmm.... smacks of xr6t having more power and torque than the boss over any rev range.....