This is my first 4WD so cut me some slack for a newbie question. I have a 2021 ORP and I was just reading the manual and I notice two things. for H4, it says:

"H4 (high speed position, four-wheel drive)
Use this for driving only on tracks that permit the tires slide, like off-road,
icy or snow-covered roads. This position provides greater traction than
two-wheel drive."

Then, for maintenance, it says:

Four-wheel drive usage frequency
You should drive in four-wheel drive for at least 10 miles (16 km) each month.
This will assure that the front drive components are lubricated.

I want to run it in 4WD to maintain it but does that mean I have to take it off road or is it just fine to run it on road at lower speeds?

Also, what's the max I can run it in 4WD? I'm trying to find that but can't seem to locate it in the manual. My nephew has a 2017 SR5 with electronic locking diff and said he can run his in 4WD at highway speeds no problem but we both mentioned we feel like we read the off roads can only be run at something like 50 MPH or lower.

In 4WD the tires need to be able to slip when turning or else the drive line will bind up since the front & rear diffs will be locked together. When turning something must give and if it's not the tires then it will be drive line components breaking. That's why it's bad turn while in 4WD on dry pavement. Off road or slick roads (icy, snowy, etc) will allow the tires to slip while turning.

Dry pavement is ok if it's in a straight line but ideally it's best to do it off road or on slick pavement. I don't have any dirt roads nearby so I usually wait until it rains and the streets are slick (I am still careful to not make sharp turns). Which means the 4WD system doesn't get exercised as often as it should but I'm not worried about it.

I run mine in 4Hi on straight stretches of paved road to keep it lubed.(2012 SR5)
It is safe to run in 4HI at speeds up to 55 I believe my manual says, but I generally keep it no more than 45 or so max. The main thing on pavement is to keep it straight because the wheels won't be able to slip and it can bind up on a turn otherwise. When I find myself on a dirt road I generally switch to 4HI just for the lube affect even if 4x4 is not needed. Had 4x4's since 1974 and always done it this way and never had any issues. Was out on a back road hiway once when I hit black ice and it threw me into a spin toward the guard rail, popped it in 4Hi real fast and pulled it out, saved some damage to my truck. Enjoy your rig.

An option for pavement on straight stretches if there's no gravel/dirt nearby can be to do it in segments, rather than driving 10 miles all at once. So engage 4WD for maybe a half mile, then disengage to allow the drivetrain to relax, repeat, etc.

I run mine on a long straight country road or when it rains monthly. I also engage and disengage high and low 4wd several times before I drive to ensure the cylinoids stay active and lubricated.

my 2 cents

for 4Lo...find a nice stretch of parking lot or secondary service road (only 15-25mph), put it into 4Lo, and do the same as others are saying - drive in a straight line for as long as you can. the point to this is what also needs to be 'activated' ... the gear dog(s) that engage the Lo range. Sometimes you will hear them, sometimes you will not...when you put it into 4Lo you get this solid click that occurs as the lights come on on the dash. That part needs to be lubed each month. There are a few diff sources that say if this isnt done, in time, your 4wd system will either not activate at all, or could get stuck in 4Lo and seize up.

for 4Hi, i have a nice straight stretch of secondary road in my neighborhood that i drive a few times a month, down one hill, up the next...and that works.

for 4Lo, there is a long parking lot near my office that i can drive down and back (disengaging 4wd on the turn around) where i can slow-speed in Lo gearing.

https://www.youtube.com/watch?v=Lhx-...ghcpzi&index=3

@ the 10:47 mark...

Yea, that's what I did today since we just got a storm.

Find a straight road. There are no max speeds but there are max shift speeds which I believe is 52 for the manual case.