315s on a 8.25” rim.

[amphi_sc]

13 minutes ago, georgecederholm said:

Al,

As I was using the FMCA program, the HSR2 SA was not included in their list (see below). I have never had an issue with Regional use profiles for tires since I don't really consider our usage pattern to be overwhelmingly "Long Haul". We use Interstates, of course, but not exclusively. Some of our driving days are several hundred miles but a lot are much shorter. When we "do the Pacific Coast", we often have less than 50 miles between stops at Elks Lodges, and lots of non-highway driving. Regional is fine for me, especially since I'm using these on my Drive axle.

My local tire shop (Redburn, Phoenix) also does a good business with all kinds of trucks, local and over-the-road. I've asked if they can beat FMCA on the Continentals and the response has been that the FMCA price is less than they would pay wholesale. Do I believe that? No. Would I have accepted an answer that they weren't in a position to beat that price? Yes. Was I OK with $507/tire? Yes.

I had Michelin cracking on the XZA1 and XZA2 Energy lines, but once I started taking better care (covers when in storage, 303 spray monthly) that stopped completely. I've written off my cracking results as self-inflicted and do not blame Michelin but I'm in the minority on that (No "Michelin sucks and won't this or that" comments, please; I've heard 'em all.) But, I didn't have any sidewall checking on the Toyos after 8 years or the BFGoodrich (purportedly made by Michelin at the time) after almost 10 years. So, Michelin may be more susceptible but also less so if protected. 

I do not recall any funny odor from the Toyos but they were in the Drive axle so position may matter. I do know that they wore like iron and looked almost new when they were done.

 

George, thanks for the reply.  As I'm looking at the 16 ply load range H speed rating M 295 (or 315) size, maybe that is why your FMCA quote didn't mention the HSR2 SA.  I'll post mine below.  My local shop quoted $420 a tire plus the usual mount, balance, and disposal fees.

[rpasetto]

In the 2020 Conti book,  For the HSR2SA in 315/80R22.5, although approved for 8.25" wheels it is de-rated to 7610# at 120psi max.  That's still more than the 295/80 size of the same tire model at 6945psi.  The same derating is on for the 315 size HSA3 and HDR2 Eco Plus on 8.25 wheels. 

Since Michelin now disallows 315's on 8.25 wheels, could it be the design of the Conti tires is different from the Michelins?

 

 

 

Edited November 22, 2020 by rpasetto
removed duplicate image

[amphi_sc]

As I'm looking at steers, the 295 would actually have more capacity at 7830 vs the derated 315 at 7610.  My front axle is very close to 15k to keep the drive axle within limits by the tag carrying more.  Interesting.

[rpasetto]

 

14 minutes ago, amphi_sc said:

As I'm looking at steers, the 295 would actually have more capacity at 7830 vs the derated 315 at 7610.  My front axle is very close to 15k to keep the drive axle within limits by the tag carrying more.  Interesting.

Yes, the 295/80 Conti is rated at 7830# at 120psi.  That's the same as the Mich XZA2 Energy 295/80.  But the Mich X Coach HLZ is rated higher, 8270# at 120 psi.  (source this time is from Mich 2019 book).

I guess I'll be checking into  Conti's when "tire-time" comes around.

 

 

Edited November 22, 2020 by rpasetto

[Ivylog]

I posted when starting this thread “Your mileage and opinions may vary.” My research, opinion, and eventually 60,000 miles supports a 315 on a 8.25” rim decreases the required pressure -12 psi compared to a 295 as long as your front axle weight is 15,200 or less...the max two 8.25” rims are rated to carry. The max a 315  can carry as a dual is 7600 lbs at 120 psi with NO derating because you are not exceeding the rim’s rating of 7600 lbs. 

If you look at a 9” rim, it’s not the 9% increase in width that stands out, it’s the 50% increase in the thickness of the dish that increases its rating to 10,000 lbs.

Edited November 23, 2020 by Ivylog

[Bob Nodine]

12 hours ago, amphi_sc said:

As I'm looking at steers, the 295 would actually have more capacity at 7830 vs the derated 315 at 7610.  My front axle is very close to 15k to keep the drive axle within limits by the tag carrying more.  Interesting.

Recent comments from two members here and a friend in Portland, Oregon have convinced me to change from the current Michelin 275/80R22.5 to the Toyo 295/80R22.5 M144 bus tire. The Toyo is 41.5 x 11.9 compared to the 275/80 at 40.1 x 11.0 so I don't think there will be a fit problem. The Toyo has a higher load rating at 7830 for single wheel use which is better than the Load Range H Michelin I am currently using. The three individuals I mentioned are very pleased with the Toyo and say the ride is better than the Michelin. Ride on the front axle is a big concern of mine and we liked the Michelins because we could run them at 90 PSI with a front axle weight of 11,990 lbs. I was apprehensive about moving away from the Michelin because I thought other tires would require a higher air pressure for the same load. I was wrong. We can run the Toyo at 90 PSI just like the Michelin. Ivylog made an interesting comment that I had not thought about before pertaining to the PSI requirement as it relates to the tire footprint. The Michelin's have softer sidewalls resulting in more square inches of road surface contact for the same inflation as competing tires. Guess that can make the PSI requirements versus load capacity misleading.

[rpasetto]

28 minutes ago, Bob Nodine said:

Recent comments from two members here and a friend in Portland, Oregon have convinced me to change from the current Michelin 275/80R22.5 to the Toyo 295/80R22.5 M144 bus tire. The Toyo is 41.5 x 11.9 compared to the 275/80 at 40.1 x 11.0 so I don't think there will be a fit problem. The Toyo has a higher load rating at 7830 for single wheel use which is better than the Load Range H Michelin I am currently using. The three individuals I mentioned are very pleased with the Toyo and say the ride is better than the Michelin. Ride on the front axle is a big concern of mine and we liked the Michelins because we could run them at 90 PSI with a front axle weight of 11,990 lbs. I was apprehensive about moving away from the Michelin because I thought other tires would require a higher air pressure for the same load. I was wrong. We can run the Toyo at 90 PSI just like the Michelin. Ivylog made an interesting comment that I had not thought about before pertaining to the PSI requirement as it relates to the tire footprint. The Michelin's have softer sidewalls resulting in more square inches of road surface contact for the same inflation as competing tires. Guess that can make the PSI requirements versus load capacity misleading.

 

I had M144's on the drive axle of my Dynasty; they were great.  The "agricultural aroma" went away in a few months.  From the Toyo 2019 book,  the M144's rating max is 7830# at 125psi; However I think your wheels may have a 120psi max.  Load infl. table from their book is below; you would need to run them as higher than 90psi to carry that 11,990#.

 

[Bob Nodine]

2 minutes ago, rpasetto said:

 

I had M144's on the drive axle of my Dynasty; they were great.  The "agricultural aroma" went away in a few months.  From the Toyo 2019 book,  the M144's rating max is 7830# at 125psi; However I think your wheels may have a 120psi max.  Load infl. table from their book is below; you would need to run them as higher than 90psi to carry that 11,990#.

 

Rick,

Table says 6020 lbs at 90 PSI for total of 12,040 lbs capacity on the front axle. Why would that not be sufficient for my Diplomat at 11,990 lbs?

 

[rpasetto]

1 minute ago, Bob Nodine said:

Rick,

Table says 6020 lbs at 90 PSI for total of 12,040 lbs capacity on the front axle. Why would that not be sufficient for my Diplomat at 11,990 lbs?

 

I read the table wrong.  6020# it is.

[Bob Nodine]

Just now, rpasetto said:

I read the table wrong.  6020# it is.

Whee, thought I was get to old for this stuff.🙂