Castle Creations motor and ESC combo recommendations for the Losi Mini-T 2.0:

Micro X2 w/0808-5300kv - 18T pinion / 60T on 2s = ~18MPH
Micro X2 w/0808-4100kv - 18T pinion / 60T on 3s = ~21MPH
Micro X2 w/0808-8200kv - Stock Gearing (15/60) on 2s = ~23MPH

Note: Requires aftermarket receiver and transmitter to replace stock 2-n-1 ESC/receiver combo.

All speed estimates are with stock tire diameter, high quality batteries and appropriately sized battery connectors.
Always monitor ESC, motor and battery temperatures on new setups or when changing gearing or batteries.