gvw, I filled all four tires on my 4100 and am very pleased. My clearing project is in an area loaded with several species of thorn trees. When using my old 2N Ford even near them, I'd get thorns in the front tires, so when I bought my JD last fall, about the first thing I did was talk to the folks at
<A target="_blank" HREF=http://www.arnconet.com/Superflex.htm>http://www.arnconet.com/Superflex.htm</A>. They gave me a dealer's name about 60 miles from here and I had it done. It's not cheap, but neither are having those pesky thorns removed. I think I added about 400 lbs to the rear and it did help the stability and traction with R4s.
<font color=green>Duane</font color=green>