Just purchased my White 2007 H3 last week and ready to make it my own...

Just ordered a black brush guard, getting the stock rims powder coated black, and putting BFG MT 315/75/16 on them. Still deciding on if I should go with 2" ReadyLift or just crank it myself...I figure I'll do one or the other. As I just got it, I'm leaning towards just playing it safe and getting the ReadyLift. Sound okay for everyone? I'll be sure to post before/after pics. Here's a crappy cell phone before pic...

 

if you go 315s. i would crank the t bars to 23.5 hub center to fender lip. alignment. get the trail duty shocks and bump stops. wheel it. good luck!

 

If I got 305's...do you still need to get the PCM tune?

 

Do you plan to go off road? The bigger tires will hurt your stock crawl ability.
I have an H2 with the stock 35's and I think 4 lo needs to be lower. Wondering how the h3 will be in 4lo with 35's. Just a thought. Real nice H3 you got there!

 

The short answer is that you should get the PCM recalibrated for whatever tire size you run.
Speedo & Odometer are calibrated for stock tire size 265. Any thing else will be different and no longer accurate for speed or distance.

 

Most H3's that are wheeled run 33s or 35s

 

I was only asking because the PCM process seems like a pain in A. But if it's necessary for any upgrade in tire size then it is what it is. Did people that used PCMforless.com just do the loaner? I'm a total beginner with this. Sounds like they just send you a loaner, I swap it with mine and send it to them. They send my back my chip and I send them back the loaner? Good to go for around $250?

I want 315's think they look great, I don't do a lot of off-roading so i'm looking for a decent tire off tirerack.com (I can get them wholesale)... Any suggestions? And I'd like to hear about PCM experiences...anybody that would like to volunteer to help me walk through the setup before I send it off would be greatly appreciated as this is practically a foreign language to me...

 

The other thing is...I bought from CarMax and I bought a 3 year warranty. Basically it covers anything other than normal wear and tear for a $50 deductible. Pretty sure any other size tires will void my warranty if any problems occur...Anybody dealt with Carmax before?

 

Yes... dealt with carmax. I would say they would blame your bigger tires for your windshield wipers not working and void any and all repairs. If I were you and wanted to run bigger tires get a set of extra rims(used craigs list is full of H3 rims and tires.) and save them for when the H3 breaks or needs to go in for service. Just my 2 cents but warranty companies love to void warranties. Especially when big tires are involved that are not stock!

 

That 2007 in the picture looks like it has 32s on it. What package is it. Does it have the locker and 4:1 transfer case? If it doesn't then I think the tires are 32s. Regardless, you may see 315s hit you at the pump and in the engine compartment.

The computer tune would be needed to re-calibrate the speedo (although, it being a 3.7 you might opt for some other upgrades). With 35s vs. the stock 285s on my 2007 adventure it was 5 mph difference at 55 mph. When I had the 3.7 I was going to get the tune. You need to get the loaner while they reprogram yours. Or, if you swap you will need to take the truck in to have the crank done. Later, if you take your rig to the dealer there could be issues. Some people have bought another computer and had it reprogrammed so they could swap back to stock for service.

Getting the Readylift is not necessarily "playing it safe." The H3 usually (I've never heard of anyone having an issue) has enough thread between the torsion bar pork chop and the crossmember to allow up to 24 inches between center of hub to fender lip (above 24 inches is not recommenended). As you raise the front end your moving the bump stops off the lower A arm and your H3 will want to dive when you apply the brakes hard. After I was running 35s for a while I upgraded shocks. It made such a difference that one of the first things I did when I got my Alpha was to upgrade the shocks. I put Fox piggyback shocks in the rear and Bilsteins up front.

When you mount the 315s they will probably rub on the sway bar at full steering lock. When you crank the torsion bars they will probably still rub a bit being as you have the stock backspaced wheels.

You say you do minimum off-roading. In that case I would stick with a semi-agressive to agressive all terain tire (think BFG KO, Goodyear Duratrack, etc.).

I ran 35s (BFG KM) on my 2007 until a few weeks ago when the transmission gave out. GM covered it under warranty at 44k miles. I traded in for the 2010 Alpha and I think I am going to go with 305s (BFG K0) this time and see how it goes.

Good luck. Truck looks good!

Here's a picture of my 2007 (excuse the bike rack... family camping)...

SAW torsion bars cranked to 24.25 inches. 1.5 add a leaf in the rear. Fox shocks. BFG KM 315s. AR Teflon Chamer 16 x 8.