my rovers tend to topple a lot

[lammatt]

no matter how close i put the center of mass near the ground and how wide my wheels span...

is it just me? or am i doing my driving wrong?

( i dont go faster than 10m/s)

[Galacticruler]

Don't include SAS, try moving in docking mode.

[Flowz0r]

It's the magic torque you get from your probe body/command pod. The easiest way around this is switching to docking mode as Galacticruler said, but you can also rebind your rover controls to something other than WASD.

[Tw1]

SAS is only going to help, they don't add rotation power...yet.

I use IJKL for rover controls, as they are the same for modded wheels, and RCS translation.

[Whackjob]

Make sure you have at least a 45 degree angle between the rover's center of gravity and its wheels. Put on a control module. Throw on an ASAS module, point the rover in the direction you want to go, activate ASAS, and throttle up without worry. I've gotten up to 25m/s on the Mun.

[capi3101]

Lock the steering on your back wheels, pack a SAS module with it and make sure it's on when you're driving around, and drive with the docking controls (can't stress that one enough).

[Nasakev]

As capi said, locking the steering on your back wheels through the right click menu really helps. It will make your turns wider and thus more stable. If possible, try to slow down before turning. Remember, a rover going 20 m/s is moving at 40 miles per hour. You wouldn't take tight turns in a car at that speed, right?

[Tex_NL]

I am surprised nobody mentioned precision controls yet.

Toggle precision controls with [Caps Lock] (Roll/Pitch/Yaw markers change from orange to blue). Now your steering won't go to 'full lock' the moment you hit a key but it will steer more gently. This in combination with pretty much everything already mentioned should keep your wheels on the ground. Personally I prefer remapping rover keys over docking mode as it allows me to use torque independently from steering to compensate an imminent roll over (especially useful on low gravity worlds).