I just bought a 2015 3500 regular cab single wheel with 267K miles on it and immediately took it on three trips with a total of 12,625 miles and had no issues. Before I bought it the dealer put new tires, new brakes, new water pump and radiator, so I was pretty sure it would be OK and it was. Just took it in for an oil and fuel filter change, and forgot how much they charge at the stealerships! The only thing I found out that didn't work was the A/C, $450 later it is blowing cold, but that was one expense I wasn't counting on until I got to Florida last week and it was 85 degrees and the A/C did not work! Tool old for that. My 2015 5.7 gas 4x4 just turned 327K with no engine issues, can't say the same for the trans, but I am the transaster man...