Originally Posted by Pasquale

I got the upgrade within week of getting 2012 m sport model. Well worth money. Ave about 16 mpg, about same as stock 50i. Get over 20mpg with 8sp trans on the hw. The stage 2 upgrade will come out in about a month and will cost me the increment over stage 1, about $500. What will provide more power at lower rpm range below 2000.
Will get over 500 hp and 580 torque. I'm definitely getting that when available. Dinan has great warranty, I had install at local BMW. Do it and you won't have buyers remorse.