LEGO Technic 42099 4X4 X-treme Off-Roader stage 2 upgrade - even more power with only 4 extra gears! - RacingBrick
LEGO Technic 42099 X-Treme Off-Roader Power Functions mod with SBrick - RacingBrick
4X4 X-treme Off-Roader 42099 | Powered UP | Buy online at the Official LEGO® Shop US
MAXIMUM TORQUE: 42099 LEGO Technic extreme offroader => Crawler | I did maximum transmission torque just chaging 12 and 20 gears in the set. Then I've added RC tires and locked differentials.