315/80/22.5 front tires

[bobshanks]

hello all! new to the forum and have a tire question. i have a 05 4320 tag dutchstar and am considering putting a set of 315/80/22.5 tires on the front to help with the load carrying cap. has anyone done this? and if so what are the ramifacations. thanking you in advance! ps. what a great forum. bob

[bonzocfi]

Bob...I put Michelin 305/70R22.5 XRV (load range L) on my coach. This allows me to take advantage of the extra 1000 lbs available on the Spartan MM chassis. They came from Newmar with the 275/70R22.5 and from what I can tell there were a lot of Dutch Star "rough riders" out there. Since 2006, Newmar put the 305/70R22.5 on all its Dutch Stars. I would call Spartan (Chris McCord) and see what he says about your choice of tire. That might be a real tight fit. This past summer I had Spartan put Koni shocks up front and the combination of the shocks coupled with the bigger tires makes for a much better ride. It is no longer "bone jarring" going over bridge transitions and the like. She rides like a new coach.

[pawpawboyce]

is it ok to run wider tires on the front than the rear? presently i'm running 255/80 22.5. bob you mentioned 305R70-22.5 on your front and i guess the same is on the rear? i like the sound of the easier ride, but obviously i don't want to mess up. what would be the ideal pressure on the front and on the rear. observing conversation, it is a rule of thumb to run pressure in the front tires 10+- more than the rear.

boyce and lisa
06 itasca meridian 39k
06 jeep unltd tow
ox tow bar

["007"]

Welcome bobshanks to the Newmar forum & irv2.
You will have more answers coming I'm sure.
Enjoy the forum and do post often.

["007"]

boyce, you should get you coach weight and balance the load you carry, at a truck scale than use the mfg's tire pressure tables for correct tire pressure.
You may find a softer ride while traveling.

[GaryKD]

Hi pawpawboyce,
Welcome to iRV2. No, it is not a rule to run the front tires 10 lbs more than the rear. One needs to have the coach weighed. Preferably get the weights on all four corners. Then, go to the tire manufacturer's web site to obtain the proper PSI that should be in each tire. The Michelin PSI charts can be found at Michelin Americas Truck Tires Reference Materials Page Download the Truck Tire Data Book.

[Route 66]

Front and rear tires do not have to be the same size, but switching to larger front tires may not result in more load capacity if the present tires are sufficient for the GAWR.

Most of us run higher pressures in the front as there are only 2 tires to support the load and rear has 4 tires to carry the load.

As noted in the previous posts, getting your coach weighed is the only way to know how much pressure to run.

[Ronnie Bledsoe 2006 Dutchstar 43']

I have Michellin 305/70R/22.5 on all axles and run fronts at 100 psi, duals at 95 psi and tag at 85 psi (all according to Michellin chart). I switched to Koni shocks about 2 years ago and the ride and jarring going over hiway transitions is really much better. (305/70R/22.5 are almost $700 each)

[bobshanks]

Quote:

Originally Posted by Ronnie Bledsoe 2006 Dutchstar 43' I have Michellin 305/70R/22.5 on all axles and run fronts at 100 psi, duals at 95 psi and tag at 85 psi (all according to Michellin chart). I switched to Koni shocks about 2 years ago and the ride and jarring going over hiway transitions is really much better. (305/70R/22.5 are almost $700 each)

ronnie, thanks for the info and response! when you were making your decision on the 305's had you looked into the 315/80's pros or cons.
thanks! bob

[Ronnie Bledsoe 2006 Dutchstar 43']

305's were stock on my coach. Have not considered changing them out. Koni's were installed in an effort to smooth out the ride when hitting the road transitions and the rough roads here in Ca. I'm satisfied with the Koni's