From MDT:
Towing Capacity - Riding Mower
As a general rule of thumb, using a single-axle trailer and a properly maintained and adjusted tractor, you should be able to pull approximately half the weight of the tractor fairly safely and with control over level ground and over slopes less than 5 degrees.
>The 1000 Series & LT1500 Series can handle a typical lawn cart with a 750 lb. capacity and a lawn roller of 650 lbs.
>The iSeries can handle a lawn cart with a 1500 lb. capacity and a lawn roller of 950 lbs.
>The GT1500 Series can handle a lawn cart with a 1500 lb. capacity and a lawn roller of 950 lbs.
>The 2500 and 3000 Series can handle a lawn cart with a 1500 lb. capacity and a lawn roller of 950 lbs.
Bruce