I now have 105,000 Km on mine and except for all the reflashes, G30 recall, replacement of the EGR Valve, Cat & DPF (under warranty) the truck remains a very reliable ride. With the AX reflash the milage has begun to climb up a bit however on the down side milage is worse in the city and the EGT temps during Regen are not as extreme as previous. According to my oil Analysis samples it is recommended to stay with the change interval as indicated on the overhead consul if you exceed the consul recommendation the wear indicators increase and the soot contamination rises sharply.
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2007 6.7 L, 2500 QC, Laramie, SB, 3.42, Mag-Hytec, 68RFE, Harvard 156L Bypass Oil Filter, Patriot Blue, 4X2, Michelin LTX Summer, Nokian Hakkapelitta Winter, Roll-n-Lock, HERD Bumper, Espar Cab Heater, Sirius, AY Reflash, SS636, 5050XL, PMT, Have Truck, Will Travel