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  • Tire Options?

    Posted by Chas on March 28, 2014 at 11:24 am

    Been looking at getting some new tires due to possible damage with an under-inflated inner drive tire.

    Seems Michelins are on national back-order and Michelin is saying they wont be avialable for up to 6 weeks! These are for the XZA2 Energy 315/80R22.5. These are 22 ply with load rating of 9300 lbs (or so).

    Looking at other options and Toyo, Continetal and Firestone all have tires in that size for a coach application. Problem is they all seem to be 20 ply with load ratings of 9090 lbs.

    So the question is has anyone any recommendations on any of the other brands in 20 ply? I am more worried about the load rating/lower ply then anything. Price is all comparable, so no issues there (Goodyear has a tire option, but it’s about $200 each more expensive then the others).

    Toyo tire is the M144A

    Firestone is the FS400

    Conti is the Coach HA3

    I would be getting two (new tires would go on steer and existing steer would go on the drive axle). Problem is I would then be tied to getting other tires later down the road of the same kind. So dont want to get something now that isnt a good option, only to have to throw them away when Michelin has more of the XZA2 in stock (or be forced to get more of the lesser ply tires).

    Paul replied 12 years, 5 months ago 8 Members · 10 Replies
  • 10 Replies
  • AL

    Member
    March 28, 2014 at 11:52 am

    Michelins are highly regarded, but others have used a lot of different brands with success.

    In your position I would not hesitate to select any of the tires you mentioned. If I am right your front axle likely weighs around 14,000# so any of the tires will not only not be pushed to the limit, but will have ample capacity. Then when the tag axle tires are replaced they can go right to the tag.

    I have had good service from my Michelin tires but I also had Chinese tires on the drive axle of my previous coach and they preformed very well and provided a nice quiet ride.

  • Archived

    Member
    March 28, 2014 at 5:28 pm

    Not sure rotating two fronts to one side of drive is a great idea. Inner and outer drives on one side must be the same diameter or one will scrub the other as you drive; same as differing tire pressures. Obviously, if both front tires are worn perfectly equally, this is not a factor. In your situation, I think I would probably install the 2 new tires on the same side of drive axle.

  • Archived

    Member
    March 28, 2014 at 6:12 pm

    Is it Michelin or a dealer telling you they are not available? Maybe another dealer has some stock, just not the one you are talking to??

  • Lee

    Member
    March 28, 2014 at 6:30 pm

    I was not believing the tire shortage story so I called my tire guy who is one of the biggest truck and rv tire companys in the desert. He said it is for real. Every year this happens but it is usually not a concern. With the new discount programs they ran short and the impact is being felt everywhere. They do it every year to keep date codes fresh. They will have all you want soon, I imagine the big guys will get them first.

    Later

    bv

  • Ken

    Member
    March 28, 2014 at 8:45 pm

    Joel,

    I don’t follow that logic. Why would you not put new tires on the steer and move the steer to the drive? Tires rubbing because they were on the steer then mounted side by side on the drive? I don’t get it.

  • Greg

    Member
    March 28, 2014 at 9:08 pm

    I just got 8 XZA2’s last week in Shreveport LA. Got them on the Advantage program.

    I have used Toyo’s before and they were ok but I think their speed rating is 65 mph, ck that out.

    When I got the tires last week had to get rid of 2 of the Continental Coach tires. They seem to be pretty good tires although I only had a few 1000 miles on them. A tour bus lease company at home only uses the Continentals on all their coaches. Pretty good looking tire, rides we’ll and stays bright and shines, lot of silicone in the compound I guess.

    Have also had Goodyear 670’s before also.

    Long story short, I like the Michilen’s. Rated at 75.

  • Archived

    Member
    March 28, 2014 at 11:03 pm

    I move my steers to the tags when I get new tire and buy 4 new tires for the drives. The reason is I don’t want unequal tires of different sides of the differenial. Am I wrong?

  • Archived

    Member
    March 29, 2014 at 2:37 pm

    The tires on the drive don’t touch each other (maybe I wasn’t clear enough) but if there is any significant difference in diameter between tires on one side, they will attempt to rotate at two different speeds, the smaller one faster and the larger one slower. That difference can cause the one tire to try to ‘speed up’ the slow tire causing stress at the tread and shifting the load to the larger tire. This is also why the dual’s equal pressure is important. Some have kits which interconnect the duals to balance air pressure. I’m not sure if this is a significant enough issue on EVENLY (if possible) worn fronts, but I do know that you would never want to put a used and new tire on as a single dual.

    The second issue is having two new duals on one side with two used duals on the other. I would be very concerned about this if we had limited slip differentials, but I doubt it’s an issue with our ‘open’ diffs’.

    Of course, I have none of these issues since I run super singles on my drive. My life is simplified unless, of course, I ever (when?) have a drive tire fail!! I’ve probably just jinxed myself.

  • Sid

    Member
    March 29, 2014 at 5:31 pm

    Slight variations in tire diameter are tolerable. What is unknown is at what point does the difference in diameter begin to create problems. Ideally all 4 tires on the drive need to be the same. If I had 3 tires the same, and one larger (such as to replace a bad tire) I would over inflate the larger tire by 10 to 15 PSI assuming it would carry a slightly greater weight than the smaller one next to it. It wouldn’t take long for the diameters to get equal or near equal.

    The tires on the same side are not going to rotate with respect to one another even if different sizes. They cannot. They are both bolted to the hub.

    If I had 2 larger and 2 smaller diameter tires I would pair up the tires of the same size and mount them on the same side. That means the smaller tires are going to revolve more per mile than the side with the larger tires. But again no big deal if they are nearly the same size as the other side. I have no idea how much difference is acceptable. The differential is not impacted by different revolutions from side side. It is designed to operate that way. Drive on small curvy roads and you will recognize the differential is dealing with tires on each side going at different RPMs.

    I will look to see if there are any limits on size variations.

  • Paul

    Member
    March 29, 2014 at 5:43 pm

    Yes, you may run same size tires but with different load ranges as duals on the same axle provided you inflate all tires to no more than the maximum inflation limit of the lowest load range tire. Keep in mind, the tires must match within 1/4” diameter (3/4” circumference); so if you are running tires of different manufacturers, tread depths or patterns, it would be wise to confirm that they match within these limits.

    The same would apply to the steer, as long as the lower load range tire is capable of carrying the axle load. However, it is generally preferred that the steer tires match in all ways possible, and mismatch of this type would normally only be seen in an emergency situation and would be corrected upon return of the vehicle to the maintenance facility.

    The above is from the Bridgestone truck tire site.

    “Tires must match within 1/4″ diameter” meaning that Bridgestone has defined the limit from their perspective.

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