Great....so when I take mine to a Dyno operator using a well know US brand Dyno, how do I persuade them to use the US method and not the UK one?
More to the point, if this IS true, then a US car on a british dyno with a lower power reading will still run the 9.5 second times it ran in the US.... but they don't? They're always shocked by how slow they are over here. And they usually end up going bang!
I do totally agree that the more factoring you do with the results, the more innacurate they're going to get (just look at the differences between the same dyno on different runs) but I think there is more to it than just this.
Like the big-power jap cars that are imported with Dyno graphs showing 1000hp or more, but on their first run here just won't break the 800bhp barrier.