to be totally honest with you unless I'm plowing in a very wet field in the early spring in upstate New York I really don't lose that much traction if she starts to slip I just thrown in four-wheel-drive and away I go, I think the tire choice would be more problematic on a 2 Wheel drive tractor. there is no doubt R1 will give you best traction but, is it worth your lawn for the few times you'll need that kind of traction . I plowed and disk about 60 acres this spring and about 40 acres of land clearing rocking tree limbs and a whole bunch of other stuff during the winter maintaining my 1400 foot driveway and barnyard,snow blowing ,plowing with the loader lots of snow sometimes 3 feet in a storm mostly Nor'easters I've yet to have one incident of being stuck with my R4 tires not to mention they definitely handle heavy loader work less flexing in the side wall and a little more puncture resistant in the end either tire will do,it's too bad you couldn't try both tires to see which would be the most productive on your property .