I am getting new turf tires this friday for my 51 8N. I pulled out the tractor manuel to see how much fluid to run with my appliciation. Which is pulling a finish mower, cultavator (small garden),brush hog, blade (light work), disk and a carry all. The manuel was no help, it gave me the percentages and what they weighted and told me the less I installed the better fuel econmey would be result. I sure the fluid is the sodium and don't want to reinstall, so the less new anti freze I buy the better for my wallet. But I don't want to be spinning all over the place. The tires now have 90% fluid. Thanks Rick: