The new 42099 LEGO Technic X-Treme Off-Roader does lack torque as it can barely make it over a couple of books on the living room floor, so here’s my attempt at upgrading the model by switching two sets of gears over, as described by Racingbrick - credit to him - plus a few practical tips of my own.

You can see the original speed build here:
   • LEGO Technic 42099 4x4 X-treme Off Ro...