[skellyo]

You're overgeared IMO. You're geared for 58mph. When you account for a small amount of ballooning, you're setup for low 60's. Running that gearing with those tires in any grass at all is going to recipe for heat. I'd drop down to something a bit lower on your pinion, like 13T or so. Or go up on your spur and drop your pinion. If you want to be in the 45mph range, you'll need something like 13:90.

Differential Ratio: 1
Transmission Ratio: 2.727272727272727
Other Ratio: 1
Spur Tooth Count: 83
Pinion Tooth Count: 17
Total Voltage: 11.1
Motor KV: 4800
Tire Diameter (inches): 4.9
Tire Ballooning (inches): 0
Motor Current Draw: 0
Motor coil Ω: 0
Spur/Pinion Ratio: 4.88 : 1
Total Ratio: 13.31551 : 1
Tire Circumference (inches): 15.39 inches (391 mm)
Total Motor Speed: 53280 RPM
Vehicle Speed: 58.33 mph (93.7 km/h)
Effective KV Value: 4800
KT constant: 0.28 oz-in/A