Tag at 70 psi according to Toyo?

[John C]

I am changing all my 8 tires to Toyo M144.

Ordered the tires from tire store, they will install those tires for me. When I told them Monaco Tire Chart (see attached) they just blew it off , they told me that it is 2024 and the rules and tires are changed, they told me for the front I should have at lease 120 psi ,driver and tag at lease 105 psi. they also said the low tire pressure 80 is bad for the tire.

Their only business they do is tire for big semi truck and I hope they know what they are talking. Does what they told me make any sense?

I understand that I need to weight my coach first and depends on the weight of each axle, I use the chart for the tire pressure.

1) my Tag Axls, the max GAWR is 10k, on each tire is 5k, looking at the chart, for single tire for 5,200 lbs is 70 psi.

2) for driver axle, the Max GAWR is 20k lbs, each side is 10k lbs, with two tires on each side, it is 5k each tire , looking at Toyo chart, 5k weight the psi should be 85 psi

3) for front axle, the Max GAWR is 15k lbs, each side is 7.5k lbs, looking at Toyo chart, 5k weight the psi should be 120 psi 

This  is pretty much inline with Monaco Stick on my coach except the Tag alxe, the 70 psi (that is even with MAX GAWR) seems to be really low for me if I following Toyo's chart.

 

Also this is the MAX GAWR, I am not full-timer, giving the Dynasty have ccc of 8,000lbs(maybe more??), I doubt I would carry more than 3K weight with me (include passenger & driver)

so my GAWR(s) will be much lighter than the MAX rating. does that means my tire pressure should be even lower?

I am going to get the tire install first, of course I don't have anything loaded, what psi should I have on each tire at a starting point (can't weight right now ,need to get Non-commercial B driver license first to go to weight station)

 

 

Please advise.

Thank you!

 

 

 

[redstickbill]

John,

After the tires are installed I would go to a truck service plaza and weigh the coach at each axle, then set the tire pressure for each axle weight.

As soon as you can get each set of tires weighed separately, with the coach loaded as you would have for a trip, then set the tire pressure for heaviest each axle.

Bill B 07 Dynasty 

[Dr4Film]

My 2006 Dynasty wall sticker states the same identical information, 120/85/80 psi - Steer, Drive & Tag.

There is a label maker strip mounted in a cabinet above the drivers seat that has Steer at 115, Drive at 105 and Tag at 95. Some previous owner had made that up.

After talking with Frank McElroy, plus referring to the tire manufactures charts, I am running the Steer tires at 115, Drive tires at 100 and the Tag tires at 85 psi.

The Steer tires are Toyo's M-144 and the Drive and Tag tires are all Goodyear Fuel Max 11R tires.

I have not done any corner weights on the coach when it is ready for our travels to New Hampshire and back. One of these years I will do that.

[Paul J A]

 Before you have an opportunity to weigh the coach I would use the following inflation in the tires;

Steer-- 105PSI   Drive--  95PSI, and Tag--85PSI  And set the DOWN pressure on the tag axle at 46-48 PSI.  Odd no one has mentioned that. Very important for proper weight distribution . 

Then. when you can;

WEIGH YOUR COACH. Four , or Six corner weight is the best, but single axle weights will be OK too. Fuel and water full. Black and grey tanks empty with your stuff on board. CAT scales at many truck stops. Tell the clerk you want to weigh a coach. There is an intercom at the scale so you can communicate with the clerk. There will be 3 platforms for3 axles. Steer axle on the  first, Drive on the second, and if applicable, Tag on the third. Keep the ****ENGINE Running****, so you stay at Ride Height. Get the print out from the clerk. IF you have a tag axle, you may have to adjust your DOWN pressure to move weight as needed, and after adjusting your down pressure on the tag, REWEIGH the coach.  Now go to YOUR tire Mfg. inflation charts for the correct COLD inflation.

[96 EVO]

105psi will be too low on his steer axle tires!

Until I had a chance to run across a scale, I would stick with the suggested 120psi.

After weighing, you may be safe to drop to about 115.

[John C]

1 hour ago, Paul J A said:

 Before you have an opportunity to weigh the coach I would use the following inflation in the tires;

Steer-- 105PSI   Drive--  95PSI, and Tag--85PSI  And set the DOWN pressure on the tag axle at 46-48 PSI.  Odd no one has mentioned that. Very important for proper weight distribution . 

Then. when you can;

WEIGH YOUR COACH. Four , or Six corner weight is the best, but single axle weights will be OK too. Fuel and water full. Black and grey tanks empty with your stuff on board. CAT scales at many truck stops. Tell the clerk you want to weigh a coach. There is an intercom at the scale so you can communicate with the clerk. There will be 3 platforms for3 axles. Steer axle on the  first, Drive on the second, and if applicable, Tag on the third. Keep the ****ENGINE Running****, so you stay at Ride Height. Get the print out from the clerk. IF you have a tag axle, you may have to adjust your DOWN pressure to move weight as needed, and after adjusting your down pressure on the tag, REWEIGH the coach.  Now go to YOUR tire Mfg. inflation charts for the correct COLD inflation.

Could you please elaborate on " set the DOWN pressure on the tag axle at 46-48 PSI. " no sure I understand that.

Thx

[Dr4Film]

39 minutes ago, John C said:

Could you please elaborate on " set the DOWN pressure on the tag axle at 46-48 PSI. " no sure I understand that.

Thx

In your engine compartment you will have an adjustable pressure gauge for the "down pressure" on your tag axle. You simply pull up the top of the black knob and turn to adjust the psi. This is while the engine is running and you are at ride height. Then push the black knob back down to lock the adjustment in position.

This should be all explained in your owners manual.

Edited May 18 by Dr4Film

[Paul J A]

2 hours ago, John C said:

Could you please elaborate on " set the DOWN pressure on the tag axle at 46-48 PSI. " no sure I understand that.

Thx

What DR4Film said.  The drive axle becomes the pivot point in shifting weight to and from the steer axle, as well as the drive axle. The weight on the tag axle is also affected but minimally. Once you weigh the coach and use all the weight from weighing to determine the correct COLD PSI for all of the tires positions,  this will all make more sense to you. you. After you weigh the coach, and adjust the down pressure, 2-3 Lbs. at a time, drive around the truck stop lot, then do a re weigh. The attendance's know this drill for coach weighs.

Edited May 18 by Paul J A
clarify

[Venturer]

FWIW: The recommended weight distribution for the drive and tag axles is to have 2/3 on the drive and 1/3 on the tag. In theory, that puts an equal weight on all tires. Personally, I prefer to have more than 2/3 of the rear weight on the drive axle for traction reasons. That also takes some weight off the steer axle giving me a higher safety factor up front. I carry about 38-40 psi in the tag suspension. This puts the drive @ 20,000 (23,000# rating) tag @ 7200 and steer @ 14,000 (15,100# rating) I carry 115 psi in the steer, 100 in the drive and 80 in the tag. My 43' Tiffin had similar weights and I ran similar pressures in it for 84,000 miles on two sets of tires. The second set was Toyo as are the current tires on my Executive.  

Edited May 22 by Venturer

[Ivylog]

Congrats on your 07 Dynasty (would have helped posting) and yes 70 psi will support 10K of weight on the tag and I would start at 40 on the tag’s airbags… had a 04 Dynasty for 14 years. I would start at 110-95-70 until you load and then weigh. Most charts don’t go below 70 psi as supposedly that’s the minimum to keep the tire on the rim,

[John C]

Just drove to the tire and replace all tires.

Here is what I did:

steering : 115 psi

drive: 95 psi

tag: 85 psi

On 5/18/2024 at 1:55 PM, Dr4Film said:

In your engine compartment you will have an adjustable pressure gauge for the "down pressure" on your tag axle. You simply pull up the top of the black knob and turn to adjust the psi. This is while the engine is running and you are at ride height. Then push the black knob back down to lock the adjustment in position.

This should be all explained in your owners manual.

I just read the manual on performing the stabilization procedure:

...

"Raise the tag axle using the tag axle switch on the shift panel"

Is that the "tag lift" on the valid keypad?

How do you know what is the right downward force to set? how do you know the the downward pressure should be 38 psi instead of 20 psi?

Please advise.

Thanks!

[Ivylog]

Until you weigh you won’t know BUT I doubt anyone uses less than 35 psi. Our rigs tend to gain weight over time and it’s a good idea to weigh every couple of years.

[John C]

6 hours ago, Ivylog said:

Until you weigh you won’t know BUT I doubt anyone uses less than 35 psi. Our rigs tend to gain weight over time and it’s a good idea to weigh every couple of years.

Understood.

What is the formula to calculate the right downward force?

[Ivan K]

There's no formula, final setting is a trial and error at the scales, no one knows your payload weight distribution. Mine is at 47 psi but I know to get on the scales again as stuff was added and moved. Your manual would have the stabization procedure.

Edited May 23 by Ivan K
Sp

[96 EVO]

45 minutes ago, John C said:

Understood.

What is the formula to calculate the right downward force?

Ideally you want the same percentage of weight per axle gross weight rating, but, in reality, it's usually not possible!

Usually, you would be over 100% GAWR on the steer axle before you reach 75% GAWR on the tag axle.

[grizzly]

you should have chart in your manual for front, drive and tag settings according to your weight on each tire ideally. I just weighed my axels and did it that way. my weight is pretty even from side to side. Then adjust tag axel with more or less down pressure to get less  or more weight on drive axle making sure to stay inside of the limits

[Paul J A]

1 hour ago, John C said:

Understood.

What is the formula to calculate the right downward force?

WEIGH YOUR COACH. Four , or Six corner weight is the best, but single axle weights will be OK too. Fuel and water full. Black and grey tanks empty with your stuff on board. CAT scales at many truck stops. Tell the clerk you want to weigh a coach. There is an intercom at the scale so you can communicate with the clerk. There will be 3 platforms for3 axles. Steer axle on the  first, Drive on the second, and if applicable, Tag on the third. Keep the ENGINE Running, so you stay at Ride Height.Get the print out from the clerk. IF you have a tag axle, you may have to adjust your DOWN pressure to move weight as needed, and after adjusting your down pressure on the tag, REWEIGH the coach.  Now go to YOUR tire Mfg. inflation charts for the correct COLD inflation.

 

 

 

[John C]

OK, so it looks like trial and error then.

Thank you!

 

[96 EVO]

8 hours ago, John C said:

OK, so it looks like trial and error then.

Thank you!

 

Pretty much!

40psi on the regulator is a good starting point, then when you get it on a scale, you can make small adjustments from there.

You will likely end up somewhere between 38-50psi.

Edited May 24 by 96 EVO