GIF via Team O’Neil Rally School YouTube

Team O’Neil Rally School shared a video recently about the differences between braking with two-wheel drive and four-wheel drive, but people complained the test methods were unfair. So, the school tested it again, and drove home their surprising point: A 4WD system can actually brake better than a 2WD one.

In the first 2WD-4WD test, Team O’Neil used a Ford F250 and concluded that driving in 4WD mode helped reduce the stopping distance. It was a weird result considering that 4WD and 2WD systems are what help a vehicle move instead of stop, and it left questions: Did the systems make the difference, or were the trials driven differently? Commenters, for example, complained that the truck could have been going different speeds, and that the test methods were flawed.

In order to remove any doubt from the retry, Team O’Neil put two Jeeps on the same tires and found a similar patch of snow and ice to test them on. One Jeep was in 2WD mode while the other was in 4WD, and we can clearly see that the cars are going the same speed this time around.

The school then switched the Jeeps’ modes and ran the test again, in order to ensure the same effect on two different vehicles. Here’s how the Jeeps did:

Team O’Neil noted in the description that this result is only for part-time 4WD vehicles with standard transfer cases, not full-time 4WD or AWD systems. The difference there is that with part-time systems, the vehicle operates by default as 2WD and its 4WD system works differently than a full-time one.

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The part-time vehicle can be switched to 4WD, but the system locks the front and rear driveshafts and doesn’t allow for them to operate at different speeds like a full-time system does. Switching to 4WD on a part-time system should really only be done on loose surfaces and in off-roading, not on dry roads.

Despite 4WD doing a better job of stopping the car in Team O’Neil’s test, the difference wasn’t that glaring with other factors kept the same. But it was odd in the first place that one system had an advantage over the other, and that’s now been backed up with a second test.

The only difference this time, of course, is that viewers have fewer reasons to challenge the results.