I've put a lot of miles on both double and triple axle trailers. Yes, it cost more for tires as you have two more. There is another pair of bearing to pack also. I haven't noticed a big difference on tire wear as mentioned above even though it is correct that you get a sliding motion as you do with even the double axle too. I rotate my tires. If you want to have fun, go to your local tire store and ask for a 5 wheel rotation, no body seems to know how to do that anymore. Personally, I prefer the triple axle. I have a 36 foot Cardinal with triple axle. Never lost a tire on it but have on gooseneck trailers of both type and get less negative reaction from the triple axle trailer. Good Luck.