I am thinking of buying an H3 and have a few questions on the 4WD system. 1st question is what is the difference between the 4HI and 4HI lock. 2nd when i am driving in normal conditions is it in 2HI or is it all wheel drive all the time? and my final question is what is the realistic gas mileage of a stock H3 city and highway.

Thanks Brian

 

The H3 has a full time 4WD system. when driving in 4Hi you are getting a 60/40 split rear to front.
when in 4Hi lock you are locking up the center diff and now the power is 50/50 split.

There is no 2wheel drive at all.
Gas milage seems to vary a bit from truck to truck and based on how you drive, but you expect to get 14-16mpg city and maybe as good as 20 highway.

 

Is it the type of 4wd system that all 4 wheels spin at the same time? I have a jeep liberty my wife drives and when that gets stuck in the snow I get 1 front wheel and 1 rear wheel spinning.

 

It has traction control. When wheel spin is detected, the spinning wheel is braked sending power to the other wheel. There are a lot of good posts on this. You can find them by using the search feature.

 

I believe also that mpg might be based on where you live. Meaning elevation, air quality, and how much lead is in your foot. I went to New York City (about 600 miles from me) and I got 23.7 mpg, but I also added acetone in my gas tank, when I drove back I got 18.5,,,, horrible just horrible... in the city I average around 16-17

 

Another answer is that it depends. By nature the 4WD will work similarly to the Liberty with the traction control system as RKSmith163 said. If you have an Adventure model, it will have a differential lock on either the back diff or both diff's for newer models - I believe 2009 was the first with both diff locks.