I have a 5 wheel trailer with ST235/80R16 tires for the G load range. A pair of these ammo weighs only 3 pounds. but they are really strong. With a few on each side of the trailer, I'm sure it won't roll. So 4 rounds and a total of 6 kilos - I'll take it! Yes, maybe a little more expensive than the old ones, but it was Β£18! love these new ones.