So I was curious the other day how fast you should go in 4L, so I decided to google it and that’s when I read that there’s a maximum recommended speed for 4H as well. I also read that it’s bad to use 4H on dry pavement (besides the fact that you’ll get less gas mileage). Is that true? What about in towing scenarios? Also since I read conflicting information, how fast would you go in 4L and if applicable, 4H? I don’t own a 4WD vehicle btw I was just curious.
I don’t own a 4WD vehicle btw I was just curious.
I didn't see this at first. It's going to depend on the specific vehicle.
4L is for severe conditions so you're not going to moving more than a few miles per hour at most. It's for getting out of a severe conditions, or sport such as rock crawling. You won't be moving fast, just a few mph at most and the engine will be roaring. My '99 Jeep Cherokee has 4L and I've on occasion used it to get going in deep snow.
How fast in 4H? If you have a center differential so you can use 4H on dry pavement you can go as fast as the vehicle is capable of going. I used to own a 4WD AMC Eagle and you could drive as fast as you liked in 4WD until the car couldn't go any faster. (The Eagle didn't have low range.)
If you don't have a center differential, like my old Cherokee, then you can only use 4H under slippery conditions, and your speed will be limited by those conditions.
My Ranger needs to be stopped, taken out of drive and into neutral before 4L will engage. 4L provides a lot more mechanical advantage to the engine (very high torque multiplication, sacrificing speed, you can't drive more than a few miles an hour), I've never used 4L and my grandparents live on a steep, unpaved incline on a farm.
My Ranger is capable of using 4H all the way to highway speed if the roads are slippery. I would never take it at that kind of speed if the roads are slippery, because I like breathing.
Traditional pickups could do damage to their differentials on dry pavement if you attempt to turn. Driving straight on a paved surface is fine if you don't make any turns. I have a 4-mile drive down a needle straight road that I occasionally use to exercise the 4x4.
Even if you don't drive in 4WD, if you have permanently locked hubs, you're going to get worse gas mileage. My Ranger had permanently locked hubs when I bought it. I would average around 14 mpg. When I bought changeable hubs, I unlocked them and I got 18 MPG.
It might help if you provided a few vehicle details. What does it say in your owner's manual?
