Now think about this...I talked to one of the forged wheel companies to get a weight on 1-piece forged wheels in stock sizes. The fronts would be around 26 lbs and the rears 29 lbs...so each front is 15 lbs lighter than stock and each rear is 13.5 lbs lighter than stock. Adding it up, that's a whopping 57 lbs of rotating unsprung mass being dropped. Add in the tires (using Michelin Diamaris as an example), and that's an almost unbelievable 93 lbs of rotating mass that can be dropped. I've never heard of anything like that. In most cars, the only way to drop 93 lbs of rotating mass is to remove the wheels completely. But then the car wouldn't exactly be faster. :-)

I can't imagine what this thing can do with chip AND lightweight wheels/tires. Mid 11s? The only caveat is its probably best not to go with race lightening or anything along those lines for any aftermarket wheels as that may make the wheel too weak to handle the X5's weight. But those numbers I got for weight were for standard 1- piece forged.

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2017 Nissan GTR Red/black - Tune/midpipe
2013 BMW X5 50i M-sport Alpine white/black - Dinan stage 1
2016 Jaguar F-Type R Gray/red