I bought my 2003 Duramax Allison GMC Crew cab 4WD 2 years ago $17,000. It had 165,000 miles on it. I am at 179,500 now and going strong. Some diesel owners told me that many miles was just broke in. I did not hesitate. My 2003 had fuel injector issues, but the dealer I purchased it through reported that ALL injectors were dealer replaced already. So I should be good for 100,000 miles IF I take care of her. I just had the transmission fluid changed, and the transmission shop told me ALL looked good. Now this truck was very clean, and looked like previous owner took re a lly good care of it. I was recently thinking upgrade to a 1 ton, and I have heard MANY say to be careful with the FORDs diesels 6.0L (unless they have hadthe "bulletproof" kit installed- EGRCooler deleteand new head studs) and the one that followed 6.4L (injectors) I am not a FORD diesel owner, but I just talked to a diesel mechanic who parked a 2015 Cyclone 3100 next to my 2014 cyclone 3100 this weekend. He said the Fords are what he is working on most these days. He was driving a 2009 Duramax Chevy 2500HD. He told me to stick with the Duramax Allison IF I could. I like advice like that from a diesel mechanic. He did say avoid the years where they dump extra fuel to help with emissions, DEF? I have nnot heard anyone complaining about the Dodge Cummings diesel. I decided I cant afford to upgrade right now, so my 2003 D/A is off the market, but I love my truck. Also, I was told if you are pulling heavy camper, the gasser is not as strong as the diesel. But diesel is $4/gallon. At least gas comes down once in awhile. Diesel maintenance is noted to be more expensive than gasser. I am hoping to start doing some of my basic mainteance. Good luck.