Opinions on running 4X4H at 70-80mph?

I have to drive a lot in the mountains on I-70 in Colorado in snowy/icy conditions. I usually run 4H if there is any snow on the road or if the roads are wet in sub freezing temps. They do a pretty good job maintaining the road conditions, so I can safely run 70-80mph at times on long straight aways. Will running those speeds in 4H cause any damage/problems to my taco? I’ve read a lot of people saying that you shouldn’t run faster than 50-60mph, but my Tacoma seems to run great at 70-80 in 4H. Thoughts?

2018 TRD Off-Road 4X4

 

You can't engage 4HI over 50 something mph per the manual, but I have driven all sorts of 4x4 vehicles in 4hi at freeway speeds.

Your gas mileage will suffer, but I wouldn't worry about doing it.

 

No problem at all running 4h at any speed. It was designed to go as fast as the truck will let it, just actuator max speed is 60

 

I don’t have any helpful info that actually answers your question, but I think if the roads are “safe” enough to run 70+ mph then you probably don’t need to be in 4x4.

Just my .02

 

Isn't it foolish to travel that fast in conditions that would require 4wd?

I'm speculating here, but the transfer case and front gear set may not be designed to handle load above 50mph. There's probably valid reasons Toyota advises against it, so I'd err on the side of caution.

 

I do it all the time here in Michigan. Can have dry roads for 2 miles then the highway is snow covered. In those situations I just leave it in 4 high.

I do slow down on the snowy sections, and I hope you do too.

 

Snow/ice + 70-80 mph = brilliant

 

It’s a very windy interstate in the mountains and 4WD is required on the sharp turns in these conditions. But On the straight aways you can safely cruise at 70-80 as long as it’s not a blizzard and visibility is good.

 

Yes, the roads are very similar here. Can be dry for a while, then you are in conditions where you definitely want 4WD.

 

Actually, your MPG won't suffer at all.

Cruising in 4hi at 60 MPH or lessless be much more efficient than 80+ in 2 hi.

 

I never drive 80, but 60-70 at times while slowing down for extra snowy sections or to pass slow traffic. Won’t hurt the 4wd at all.

 

There's a great YouTube video from Engineering Explained that goes over the concept of part-time 4wd and how to properly use it ... Long story short I'd definitely slow down and not exceed the speed Toyota says (which I think is 50mph) during the turns and windy roads

 

Maybe 3rd gens are different than my truck, but I only have part time 4wd. I try to avoid running in 4wd if the roads aren't a little bit slippery. If the roads are slippery enough for me to need 4wd then 70+ mph = being in the ditch or worse.

 

It's ok if you have 4wd

 

Based on some of the logic in this thread, I wouldnt be able to drive a subraru on the interstate.

There are no issues with running 4wd at any speed and contrary to popular belief Toyota does not put a max speed on 4wd, simply the maximum recommended speed for SHIFTING into 4wd.

 

Subarus are asymmetrical 4wd which is pretty much full time unless you have an STI trim to adjust those settings .. my understanding is he's asking about how he would use the part-time 4wd system which is geared a little differendif and can only "properly" or "shouldn't exceed" a certain speed limit.

 

Subarus are All-Wheel Drive and are a completely different system than our Part-Time 4WD vehicles. They don't have a transfer case to start and have an open middle diff usually.

 

beat me to it!

 

Subaru has an AWD system that is meant for continuous use and won't bind in turns. The Tacoma is not the same.

 

We know what the difference mechanically, the point is you can drive whatever speed you want regardless. Part-time vs full-time is completely irrelevant in this discussion.

False

We arent talking about turning...we are talking about speed