Don't suppose that has anything to do with the huge heavy engine up there do you?

 

OK - I can't quite figure out what you are talking about. A tire is a rubber ring of tread. Take a piece of string the circumference of a tire and make a circle out of it. Now squish it down so that it is move ovaled. Did the circumference somehow change?

 

Can someone explain to me in plain English why changing the tire pressure on the front tires while in 4WD makes a difference. If the gear ratios are the same and the tires the same brand and size what does the tire pressure have anything to do with anything? I know there are plenty of real life experiences with 4WD and some folks break trucks and some don't, but if the manufacturer tells me not to do something I try not to do it. There is a reason why they don't recommend 4WD on dry pavement.

On the other subject of the rear tire pressure making a difference with the "effective radius", it's really easy to prove one way or the other. Find a place where you can drive a few miles on a straight road. Set your tire pressure to 40 PSI and the odometer to 0 at point A, drive to point B and note the odometer (you can use a GPS also and use the MPH difference). Now lower the tire pressure to 20 and reset the odometer at point A and drive to point B. The results will tell you if airing down makes a difference. I'm tempted to try this myself this week and report on it later.

 

I drive the beach alot in 4x4. A couple of times I came off the beach and onto the pave road and forgot to put it back in 2wd, and I can tell you as soon as I made my first turn I could feel the tires binding. Driving on a dry road in 4x4 is not a good idea (my truck does not have 4x4 auto).

The reason the 2500 requires 60psi in the front and 45psi in the back is because of the heavier front end and has nothing to do with the 4x4.

 

"Can someone explain to me"
Its already been explained... and its in english.

"if the manufacturer tells me not to do something I try not to do it"
(ROFLMAO) And you`re still going to do your "A&B drive test" and post the results regardless of your first statement/paragraph..?

"use a GPS also and use the MPH difference"
This has nothing to do with "Full Lock 4x4 bind".

 

Guys, i`m done with this post, and i`m not willing to turn this into a pizzin contest. (which is what it always ends up being on MOST forums)
Go drive your 4x4 how you know best. What works for me obviously has been fine for over 40yrs, so i`ll stay with what i know works.

 

1) You can't explain it, so I will. When in a straight line, all 4 wheels travel the same distance and there is no binding in the transfer case, there would be no binding with a 4wd on a dry or slippery surface, so it's probably OK. When turning the front and rear wheels travel different distances so binding happens. So if you try to reduce the binding in turns by lowering the air pressure on the front tires, then you end up inducing binding when you drive in a straight line.

2) The experiment does not involve 4WD, it involves the difference in effective ratio that lowering air pressure would produce.

3) The GPS will tell you the same information as my point #2. In one case the results will be based on the vehicles odometer and on the other the difference between the speedometer and the GSP speed reading.

If what you claim is true, then why don't the manufacturers just make vehicles with different gear rations in the front from the rear.

 

Out of control for such a simple answer. Dry pavement, no. Wet (although I do not as todays tires grip well), ice, snow, off road. That would be ok.

 

Wow! talk about feed back! I only asked this because people at work where trying to tell me it was bad. I always said for the amount of driving I do it should not matter.

I always say (well some times say...) "Safety First" when it come to driving. I don't care if the truck gets destroyed doing it, if it's keeps my family safe then the truck is doing it!

Thanks for all the Feed back. I love the Passion in peoples Posts!

Also on what rdculus I was told by the dealer when I bought the truck (I live in NB Canada BTW) that if there is any sign off snow on the ground of if there might be turn on 4x4 and just drive careful.

I still asked the original question because salesmen can only be trusted so much... and I was one of them! LOL

 

peedog, you really do not have a clue, so just leave it alone.