Tested a bit. Seems the limit is 200 TUPS (400 BPS).
Took the jeep, raised the maxwheelspeed to 1000, then messed around with the mass.
300 mass caps me at 100 TUPS.
200 mass caps me at 150 TUPS.
150 mass caps me at 200 TUPS.
Lowering the mass further didn't make it any faster than 200 TUPS, just makes it more unstable. The wheels keep breaking.
If you go too low, the jeep starts bouncing around because of the spring force.
This is the bottomprint loop im using to test the speed, prints out in torque units.
function speedloop(%c){cancel(%c.sl);%c.sl = schedule(40,%c,"speedloop",%c);if(isObject(%p=%c.player)){if(isObject(%v=%p.getObjectMount())){%c.bottomprint(mFloor(vectorDist("0 0 0",%v.getVelocity())),1,0);}}}
speedloop(ClientGroup.getObject(0)); //(or you could do speedloop(findclientbyname("Blah")); or whatever)
btw did you know one of the fields for tires is misspelled?
longitudinalforce only has an effect if its spelled
logitudinalforce cause the devs misspelled it and never fixed it.