When you are on some lonely road in Montana, Yukon, Alaska or Newfoundland with a heavy 5th wheel trailer behind you the last thing wanted is a preventable breakdown. This is why Mark has had our truck every year for the past 10 years for its annual very thorough preventative maintenance service. Except for a couple tire failures, on the trailer, we have not been left stranded because of truck failure. The calls to give options on repairs/replacements are a nice touch.