Guest Posted: By Dave C.
Last Updated: 6th January, 2020
What is the difference between 4wd Auto and 4wd Lock?
4WD Auto is like all wheel drive. It has a clutch design in the transfer case that allows slippage so that it won’t bind up on dry pavement. It is for use on mixed terrain such as partially snow covered roads, etc.
4WD Lock is like a standard 4WD for slick surfaces only and has the front and rear locked together. When you engage 4WD LOCK, it engages/loc the front axle to the speed of the rear axle. That is all it is, that you engaged 4wheel drive.
What is the difference between 4wd High and 4wd Low?
Without an Auto setting, 4WD High is what you’d use in any situation that’s low-traction but relatively high-speed—a dirt road or snowy paved road. 4WD Low is strictly for slow off-roading or places where torque multiplication would really help you out (like deep sand).
Is it bad to drive in 4×4 on the highway?
Or is driving in 4WD mode on a highway safe? The short answer is: Yes, it’s perfectly safe to drive in 4WD on the highway. But you still shouldn’t do that – unless you have to.
The 4WD Setup
In a 4-wheel drive, you have an additional rear axle. The power from the engine goes to both sets of wheels – front and rear. It’s as simple as that.
As a result, with a 4WD drivetrain, you have control over the rear wheels, as well as the front. If the front wheels lose their grip on the road for any reason, the vehicle can still accelerate or decelerate by controlling the rear wheels.
Traditionally – i.e. in the previous century – 4WD was a big deal. Few vehicles were 100% 4WD. If you went offroad with 4WD truck, you had to bring it to a full stop, literally get out, grab a lever and connect the rear axle to kick the vehicle into 4WD mode. Then along came SUV’s and off-roading just for fun. People really preferred to stay inside their SUV or truck so new systems were developed with which you could engage your 4WD systems with the push of a button.
This history lesson seves a point: With an older vehicle, you still need to switch between 2WD and 4WD. With many newer trucks, 4WD is a fixed feature. Nothing to think about with those – your truck is 4WD and will be that always. With others, there’s only 2WD drivetrain available, so again, not much in the way of making a conscious choice on the part of the driver.