Test drove an 11 dmax 2500 C.C. about a mouth ago and had higher expectation for performance. This is my 3rd duramax now 2004.5 LLY, 2007 LBZ, and now it just bought 2011 LML. LBZ has an edge programer on it, and kind of though the new one would be about the same as the older one with a mild setting. Doesnt even seem to be close to the power of the LBZ. Havent towed with the new one yet, mabey i'll be able to feel the extra torque with some weight behind it. But no wheel spin kind of power like the older one has.