I've been looking for a truck and came across a 2007 GMC with the duramax. It's got the new body style. Truck has 80 000 km or 50 000 miles and real good condition. Is there anything to be concerned about with this engine? It has the LMM duramax. From my research, it appears that this is the engine that first got the DPF and other emission control gadgets put on. This, in turn, seems to have negatively affected engine performance and fuel economy. Can anyone confirm this from their experiences or knowledge of the 07 Sierra. Thanks.