Foretravel Owners' Forum

Are your tires Load G or H? Your tires are at 6600 lbs in the front (Single) and 5250 lb in the back (Dual).  That size tire doesn't show a load H, and therefore you're overloaded at 110 psi (max pressure for tire) and the rear should be 100 psi (which seems high...)..

https://coopertrucktires.com/CooperRoadmaster/media/Documents/Load-inflation-table.pdf here's a different chart with similar values that includes Load H tires for that size.

I have Toyo 177 LR H I run 120 in the front, 100 on the rear. Might be a bit high, but I'll take a little high.
Why would you be looking at a Cooper chart when you have Toyo tires?

I run Front @  110lbs (Cold)  --- Rears @  95 to 100lbs (Cold)    so far so good....  as they warm up the pressure goes up....  ^.^d   

There are two different versions of the M177 in load range H.  The tires made in Japan have higher load and pressure rating than the ones not made in Japan.  You can determine which you have by examining the tire's origin stamp.  That's why the Toyo load chart shows different values for what looks to be the same tire.

I confirmed this in discussion with Toyo.

You don't need a dealer to tell you what the load rating is for your tire whether in Asia, Europe or the U.S. Just go to the twin numbers on the side of the tire, you can see exactly what the tire capacity is for your tire with the single tire and double/dual tire rating. This is only good at the tire's maximum placarded pressure NOT the manufacturer's recommended pressure. So, no matter what the dealer tells you the tire is rated for, just look at the online tire specs. It will have the load index rating, at the maximum pressure and also the speed rating. Remember L is 75 mph and M is 81 mph.

In the attached photo of our tires, you can see the load index is 146/143 with M (81mph) for the speed rating and 120 psi for the pressure at the 146/143 maximum weight. Going to the attached load rating chart, you can see that the single tire maximum weight is 6614 lbs and if mounted on the rear as a dual, it's 6008 lbs with both ratings at 120 psi. If you reduce the pressure, you no longer have the load index rating as shown on the tire. You also lose the speed rating.

Don't ask me why there is a 2 or 3 lb difference between the actual tire and the chart.

As we are don't full time (not many tools, goods, etc), are 36 feet and because of our mountain location, almost empty tanks, we are pretty light and way under the 12,028 front axle tire load so we reduce all the tires to 105 psi. Weigh your coach and compare to the chart.

Note that some H rated tires may have a 149/146 load rating so check before buying.

Once again, if you have a 6610 lb rated tire, that's only good at the 120 psi as shown in the attachment. Less pressure and the load drops and the tire temperature increases. These are COLD pressures so will increase as you drive and should NEVER be lowered during the day.

Pierce

I beg to differ Pierce. Some of the confusion stems from two differing sets of numbers from TOYO's own charts as shown in realmacoys picture. There is nothing in those two lines of numbers nor in the footnotes telling you that it's different due to the tire being made in Japan or elsewhere. The only footnote for that tire is that it is equivalent to the smaller Michelin 275/80R22.5.
If one isn't running a full load of 7160 @ 125psi per the side wall branding. Then which part of those two lines on TOYO's load chart is one supposed to use?  One "might" figure it out based on one having H and max 120psi and the other H and max 125psi. But again, It isn't explicitly clear in the chart. And that's a glaring error for such an important item.

I beg to differ Pierce. Some of the confusion stems from two differing sets of numbers from TOYO's own charts as shown in realmacoys picture. There is nothing in those two lines of numbers nor in the footnotes telling you that it's different due to the tire being made in Japan or elsewhere. The only footnote for that tire is that it is equivalent to the smaller Michelin 275/80R22.5.
If one isn't running a full load of 7160 @ 125psi per the side wall branding. Then which part of those two lines on TOYO's load chart is one supposed to use?  One "might" figure it out based on one having H and max 120psi and the other H and max 125psi. But again, It isn't explicitly clear in the chart. And that's a glaring error for such an important item.

Jerry,

I didn't say the tires were different depending on where they are made.

I don't see it as a glaring error.

Pierce

Does this mean that the higher rated tire should not be ran at less than 95 psi regardless of the load?

According to Toyo, yes.  95 psi minimum.  They declined to provide any further info.

We need to be a little careful here, as there are comparisons between different tires and vastly different weight coaches.

And the odd thing is that Toyo's load/inflation chart only differentiates inflation data by tire size "FULL STOP" not the tire models within the same size range. 

So per the Toyo chart. My H rated M137's have the identical inflation schedule as Elliott's H rated M177's.

One might assume that the load rating for a steer tire and an all position tire may be at least slightly different, as would a drive tire.
 

My beef all along has been that in the Toyo chart. Toyo combined two different H rated carcasses. one rated to 120psi and one 125psi then also added in the G rated carcass for good measure.

Yes, and they also added the "F" rating in the same line on the 120 psi tire.