I hope this friend is in the military and you are keeping his vehicle for him until he gets back. That would be so darn nice of you. But, even if this is not a military person's truck: The best thing you can do for the truck is to drive it once a week. Treat it with care. Check the air in the tires, the oil level, all the stuff you should be doing to your vehicle. So you put a few miles on it, that's what it's for, and the best way to maintain it. Drive it, listen to it, look at it, give it back to him in better shape than when he left it---IF you are really his friend. :yes: