Watch The Hardcore Mini JCW GP Hit The Dyno

In the past, BMW Group's power estimates have been very conservative. In some cases, dyno testing has revealed BMW Group's models to be muchmore powerful than advertised. TheBMW M5Competition, for example, produces 617 hp and 553 lb-ft of torque according to BMW's official figures, but dyno testing revealed the performance sedan generates nearly 700 hp at the crank.

Before being strapped to the dyno, Evolve's Mini JCW GP had clocked up around 700 miles on the clock and was given a thorough workout at a track day.

After three runs, Evolve found that the Mini JCP GP's peak power output was 305 hp and 340 lb-ft of torque. That's slightly higher than the official specifications, but the result is very close to Mini's official claims. Impressively, the Mini JCP GP also produced more power on the dyno than the BMW M135i, which has the same engine and gearbox.

Despite having the same setup, the BMW M135i delivered just under 300 hp on the dyno. This isn't necessarily conclusive, however, as the BMW M135i may not have been running on the same fuel as the Mini JCW GP, but Evolve is keen to test the M135i again with the same fuel as the Mini to see how it compares.