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dc8cappie · 09-24-2010, 07:54 PM

In April I purchased a used 2005 Itasca Meridian 39K. As part of the deal I had new Goodyear G670RV's installed because the old tires were 5 going on 6 years old. I assume they replaced with like size tires to what were on the RV.

The factory tires were 255/80R22.5 G rated, which would require 110psi front and 105psi rear at max axile weight.

Now this might be called over kill.

The tires installed on the coach are 275/70R22.5 G rated. Required tire pressure for these tires with front and rear axile max weight of 10,410# and rear axile of 17,500# is 85psi. This pressure is for the first listed weights of the G670RV's of 5170# front and rear dual 4770#.

My question is, is this a good think or bad. What are the advantages and disadvangages of these tires.

Just as an added item, they are on aluminum alloy wheels 4, steel 2 inner.

I'm looking for peoples thought on the larger tires, Good, Bad or Indifferent?

Chime in!

paz · 09-24-2010, 09:04 PM

IMO, your new tires are a good thing, especially since they came with aluminum wheels. According to the Michelin charts, the diameters of the two tire sizes are pretty close, so there shouldn't be any significant speedo error.

With the bigger tires, you can carry the same amount of weight at lower pressure, so you should have a better ride.

One possible, but unlikely, downside is clearance problems in the wheel wells. This would probably be evident in the front with the steer wheels turned all the way one way or the other.

Another possible, but unlikely, problem is insufficient clearance between the rear duals. If there is insufficient clearance, the duals can "kiss" as they flex going down the road. Kissing can cause heat buildup and a blowout. According to Michelin, 275/60R22.5 tires need a minimum of spacing of 11.9". Measure from the outside edge of the tread on the outside tire to the outside edge of the tread on the inside tire to determine actual spacing.

CD · 09-24-2010, 09:54 PM

IMHO it would be a good thing except for the possible interference as mentioned above. I have had the opinnion for years that most Rvs have too light of tires. A few are so bad that if you load more than a sandwich and a change of clothes you will be over loaded.

Gary RVRoamer · 09-25-2010, 09:42 AM

I'd much rather have excess capacity and marginal or too little. Inflate those 255/80's per the Goodyear load tables for your coach weight and enjoy it.

Ray,IN · 09-25-2010, 01:01 PM

I'd like to add something about dual tires. DOT specifications say there must 1.5" minimum between tires.This goes along with what paz said.

1ciderdog · 09-25-2010, 04:59 PM

At the rally in Redmond, OR a couple of months ago I priced both Michelin & Goodyear for "rally discount" for my 2004 Journey 39K (which I presume would be quite similar to your Meridian 39K). I had priced both a few months prior to the rally and the prices were very close. But at the rally Goodyear had a "rally" sales price and that combined with a Camping World discount was significant. Goodyear recommended the 670 tire 265/75R 22.5 to replace the 255/80R 22.5's original Michelins. I asked Goodyear representative about tire clearance on the duals, tire circumference, revolutions per mile and other questions. One noticeable difference was Goodyear has a seven year warranty covering the sidewall cracks. I've put about 1000 miles on the Goodyear's and do not notice any handling difference from the Michelins.
Interestingly on yours they recommended the 275/70R22.5. One of these days I'll have enough energy to compare the 275/70 with the 265/75 unless one of the readers explains the difference.