Yokohama Tires

[Seville]

 I need new front tires for my MC9. I got quoted $590 each for a Yokohama 315/80R22.5 tire.
$950 each for a Michelin.

I decided on a pair of Yokohamas.

What do you all think of Yokohamas? My main concern is safety. I know Michelin's are top of the line, but 2 grand is a bit steep.

Looking for a little feedback please.

Thanks.

[muldoonman]

Don't know about yoko's but just got in from driving 80 miles and back to Love's Truck Stop in Sequin Tx. from the ranchcito, To replace 2 front 12r-22.5 XZE's and the damn mesicans only had 11r tires. Called yesterday morning to confirm. Said they had there hands on them. They don't speakeda good english, NO! I had my concealed 45 auto on me and I thought just a minute. Rant over.

[Brian Diehl]

I run Yokohamas all the way around my bus.  The first set I bought in 2003 and they are still going strong.  The new front steers I put on 2 years ago are also Yokohamas and they are running great as well.  I have about 60k miles on the original set (now on the drives and tag) and you can tell I've put miles on them, but they will age out before they wear out.  I like them and think they are a great tire.

[gus]

I've had Toyos, Firestones and Hankook - can't tell a bit of difference in any of them.

I won't buy Michelins because they are so grossly overpriced with absolutely no proof they are any better than any other tire.

There may be some bad brands out there but I haven't found them yet.

The main problem trying to find the best is most brands change their tires around so much that this years tire is not the same as the same model name last year which was rated tops.

I see this all the time in auto tires rated by Consumer Reports.

[Sean]

I need new front tires for my MC9. I got quoted $590 each for a Yokohama 315/80R22.5 tire.
$950 each for a Michelin.

Wow, how much weight are you carrying on the front that you need 315s?  For most MC9 conversions, 12R22.5 will deliver better performance for a lot less money.  FWIW.

-Sean
http://OurOdyssey.BlogSpot.com

[Scott & Heather]

Sean, please help out a newbie, what does the 315 number stand for? Tire width?


Sent from iPhone via Tapatalk

[RJ]

Sean, please help out a newbie, what does the 315 number stand for? Tire width?

Scott -

I'm not Sean, but I think I can confuse you thoroughly:

The HD truck tire market is finally switching over to metric sizing, something the auto market did what, 15 years ago?  Thus the 315/80R22.5 nomenclature.

So, same as autos, the first number indicates the width, after the slash indicates the aspect ratio (width to height), R means radial, and obviously, the last number is the wheel rim diameter (which is stuck in inches here - Metric elsewhere).

To actually compare metric to previous sizing (11R, 12R, etc.), it's best to look at a tire manufacturer's sizing charts.  Here you can glean load range, actual tire diameter, width, revs per mile and other data.  Looking at Bridgestone's site, it seems the most accurate comparisons are width and revs/mile for this particular tire example:

https://www.bfentirenet.com/product_catalogs/trucktires/app?task=TruckTiresPC&subtask=ttFrame&ctry=USA&language=en_us&target=catalog

Just as important, once you choose your tires, is looking up the inflation tables for what you bought.  The psi molded into the sidewall is usually the MAXIMUM psi, not necessarily the correct pressure for your application.  This is why it's advantageous to know how much your coach weighs overall in "fightin' trim," as well as the average weight being carried by each axle.  Many, many, many busnuts would have a much nicer ride to their coach if they'd set their tire pressure's based on the tire manufacturer's inflation charts, not just pumping them up to the maximum.  Using the same tire company as above, here's the inflation tables in .pdf format:

http://www.trucktires.com/bridgestone/us_eng/load/load_pdf/loadTables.pdf

Clear as mud?

FWIW & HTH. . .

 

[Sean]

Sean, please help out a newbie, what does the 315 number stand for? Tire width?

I think RJ did a great job explaining what part of the measurement "315" is, and everyone not already familiar with tire sizing should go to the sites he linked to familiarize themselves.

That said, let me just clarify that while "315/80R22.5" is a newer-style nomenclature, and "12R22.5" is an older-style nomenclature, these are two different sizes, not a newer/older name for the same size.

If the 12R22.5 tire was "renamed' into the newer style nomenclature, it would be roughly a 305/83R22.5, however, you won't find a tire with that labeling.

Both the 315/80R22.5 and the 12R22.5 turn nearly the same number of RPM and have nearly the same rolling radius; in fact, there is more RPM and radius variability between makes and models within either of those sizes.  And either tire will fit 22.5" x 8.25" rims, which were standard on most MC9s (9" rims were optional), although 9" rims are preferred for the 315.  However, there the similarity ends.

Because the 315 is a wider tire intended for heavier loads, it generally has a higher Load Range or Ply Rating, and heavier tread, plies, and sidewalls.  For this reason, many 315/80R22.5 tires are speed-limited (that's a lot of weight out there ~22" from the hub), and ones rated to 75mph for motor coach use are extremely robust.

In addition to making the tire itself much more expensive to build (and heavier) than a 12R22.5 model, the extra load rating earns the tire more Federal Excise Tax, which is based on the load the tire can carry.  That all adds up fast, and a 315/80R22.5 tire can cost 30% more than a similar model in 12R22.5.

On top of all that, the extra footprint of the 315 makes low-speed steering harder, and on some coaches can cause the tire to rub the wheel well or other components on full-lock turns.  Properly inflated for the same load, the 315 will also lower fuel economy compared to the 12R.

The 315/80R22.5 offers two advantages over the 12R22.5, neither of which will be needed by the average conversion operator:

1.  The tire has a much higher load limit.  If your steer or tag axle is carrying more than 15,000 lbs, or your drive axle is carrying more than 24,000 lbs, you may need to go to the 315/80R22.5 just to handle the extra weight.

2.  At any given load within the range of the 12R22.5 tire, a 315/80R22.5 tire will require less air pressure to carry that load.  For example, a 14,000 lb steer axle with 12R22.5 tires would need those tires inflated to 110psi, whereas that same load on 315/80R22.5 tires would require only 95psi.  This will give a softer ride (although, frankly, we hardly noticed the difference when we had the 315s on), and if you spend a lot of time on soft surfaces like mud or sand it might help you to sink in less.

Anecdotally, I can tell you that we switched to 9" rims and the 315/80R22.5 tires briefly because of this last issue (better float/traction off road).  We switched back to 12R22.5 because they wear better, make the coach easier to handle at low speeds, improve fuel economy, and cost a LOT less money.  We have an on-board air compressor and an inflator hose.  If we need the off-road edge provided by lower air pressure, we'll just let air out of the tires until we are out of the soft stuff and then inflate them back to highway pressure.  Tire pressure can be safely reduced significantly at very low operating speeds.

Likewise I think it would be hard for most bus nuts to justify the extra expense of 315s on coaches of average conversion weight.  The exception would be the late-model factory Prevosts with dual slides and very heavy conversions, although most of those are now equipped with even bigger "super-single" wheels on the steer and tag axles, relegating the 315s to the drivers only.

One caveat here, though:  Some 315 tires are not approved for fitment on 8.25" rims.  So if your coach is so equipped, and you really want (or need) the 315s, make sure you select ones approved for these rims.

HTH,

-Sean
http://OurOdyssey.BlogSpot.com
 

[Seville]

Thanks a lot guys. I guess the Yokohamas it is!

Thank you Sean for the info on the 315's! That is what was on the coach, so i just figured I would play it safe and go with the same thing.

Last time I weighed the bus, I was at 30,000 and change, so not too heavy.
I'll see if I can get the 12R22.5's

[Uglydog56]

I have yokohama's on the steers.  They are quiet and track well.  My experiences with Michelins have invariably involve unstable squishy sidewalls or flat spotting.  I used to drink the koolaid, but no more.  Having said that, I only run Michelins on my motorcycle.  So I guess I sip on the koolaid a little when I parched. 

[muldoonman]

Michelin XZE's 12R 22.5's on front now,no miles just age. Going with Bridgestone R250f Monday. Heck of a difference in moola.

[Tikvah]

I have a nice pair of 315/80R22.5 on my front steer.

It's time to replace my drives.  Can I buy the 11R22.5s for my drive and leave the steers where they are?

What about the tag?  Does it need to be the same as the drives?

P.S.  This is great information, and great news.  I've been watching tire prices with much pain, knowing I have to buy soon and the price tag really hurts.  But, I already see some 11R22.5 for less

[viking42]

Word of warning, going from 12oo to 11oo you can expect a 1 mi per gal loss.

[Tikvah]

I thought I was hearing just the opposite... 11R would give slightly better mileage than the 12R

[lostagain]

Tikvah, 11R is smaller diameter than 12R, therefore more rev. per mile, higher engine rpm, etc.

JC