Short answer: it depends on the vehicle, conditions, and what your owner’s manual says, but most people keep 4‑high (4H) under about 50–60 mph and often much lower on bad roads.
What “4 high” means
- 4‑high is four‑wheel drive in a higher gear range meant for driving at moderate road speeds on loose or slippery surfaces (snow, ice, gravel, mud).
- It is not designed for dry, high‑traction pavement at highway speeds; that can stress the drivetrain and make the truck handle worse.
Typical speed range
- Many manufacturers and off‑road guides suggest staying roughly in the 30–50 mph range in 4H, slowing down further if traction is poor.
- Some trucks can mechanically handle higher speeds in 4H, but if you’re going fast enough for normal highway traffic, you usually don’t need 4‑wheel drive and should be in 2‑wheel drive instead.
What you should do
- Check your specific vehicle’s owner’s manual; it will give the official maximum engagement speed and any recommended limits for 4H.
- Use 4H only on loose or slippery surfaces, drive as slow as conditions require, and never exceed the posted speed limit. If the road is mostly dry and you’re running near normal highway speeds, switch back to 2WD.
