Thank you, my machines are older but fully operational and in good shape, the heavier machine was tearing up a set of stock turf boss tires in 250hrs..that machine is 1850lbs, with my big rear on it 2200 plus..most of it on the rear tires,lots of torque, and 50hp, very hard on tires..the guys who ran these machines on the Dixie forums told me that the carisle field trax HD was the only tire that held up on them...so that's what I'm running. The smaller machine I changed from 22x11x9 to 25x13x9 when it was almost new, simple swap, readjust the deck pitch ..gained almost 2mph, and way better rear ground clearance especially with the bagger, also it goes almost anywhere in the soft grass, not quite as good as a ventrac but amazing for a zero turn ..those tires are good yet and they do ride a little better than the Carlisle. .with the thinner sidewall...