http://www.eurocharged.com/products/...-f10-m5-detail
On the Eurocharged Dyno Dynamics dyno (more conservative than a dynojet) the F10 M5 goes from a baseline of 488.4 wheel horsepower to 542.8 wheel horsepower. This is a gain of 54.4 horsepower to the rear wheels on the more highly strung technical update S63 4.4 liter Twin Turbo V8 in the F10 M5. Very, very solid gains.
These gains are achieved on pump gas, 93 octane. In addition to the horsepower gain the rev limit is also raised and the top speed limited is deleted.
This tune retails for $1,999.00. The ECU must be sent in and Eurocharged will reflash should the dealer overwrite the tune with a software update.