AANNDD... when your tires get old, you can just toss 'em out and get new ones. And the old ones don't get half your stuff!!

BTW, you can park a car for a couple of weeks with no expense, but you can't park a horse.
A horse's monthly maintainence and a truck loan payment cost about the same. The truck's paid off in 5 or 6 years, but that lousy horse will live 20 or 30 years (God help you if you propose to sell the old nag; your old tires- uh, wife- will act like you're trying to send her dear sainted mother to the renderer).