TPMS settings

[ewacowboy]

Recently purchased DRV 38RSSA with Goodyear G114 tires in 215-75-17.5 size. Tires have max load rating at 120 psi. My question is for my TPMS....how warm should these tires get before there is a problem? I can set alarms for under/over inflation as well as temperature, I'm just unsure of where to set the temp alarm. Any advise?

[thrushl]

Recently purchased DRV 38RSSA with Goodyear G114 tires in 215-75-17.5 size. Tires have max load rating at 120 psi. My question is for my TPMS....how warm should these tires get before there is a problem? I can set alarms for under/over inflation as well as temperature, I'm just unsure of where to set the temp alarm. Any advise?

[thrushl]

Set your toe pressures cold and don't worry about hot. The manufacture took care of that when they have you the max cold rating. That said, you most likely don't need 120 in each tire. Get weighed and adjust from the manufacture chart for correct pressure. Just don't run with more air pressure.

[ewacowboy]

I understand that....I guess I should have mentioned that I'm running 112 psi COLD based on my best-guess estimate of weight until I can get it weighed. These tires really do fluctuate (temp and psi) while running on the road - a LOT MORE than my Continentals did on our old coach.

[Ronbo]

I run 125 psi cold. They get up to 156 psi on the road but the temp doesn't get too high.

[GeorgiaHybrid]

Set your toe pressures cold and don't worry about hot. The manufacture took care of that when they have you the max cold rating. That said, you most likely don't need 120 in each tire. Get weighed and adjust from the manufacture chart for correct pressure. Just don't run with more air pressure.

 

Trust me, he needs to be right at 120-125psi in those tires with that rig. We are running right at 8K per axle with the same trailer.

 

As far as temps go, I try to adjust my "cold tire temp" to the season I am running. IE don't set them at 120psi in the UP of Michigan when it is -20F outside and never change it while driving to the keys in Florida where the "cold tire temp" could be 80F before hitting the road. I don't like seeing mine hit much above 150psi when on the road.

[billr]

TST recommends the high TEMP alarm level to be set at default setting of 158* F

[cruisin66]

As Billr said x2. I never see anywhere close to that temp in my tires. Most I ever see is about 105 F and that's on an extremely hot day at highway speed.

Paul

[ewacowboy]

Well then I've got a problem...my tow vehicle tires run about that temp as did my old Continental HTL2 Eco's, but these new Goodyear G114 run A LOT hotter than that. I had to increase the high limit on both psi and temperature. It's been sitting for a few months now so I can't recall exactly where I had to set it, but seems that they were running above 150 degrees while the 22.5s were running at about 85 degrees. All four Goodyears were running similar psi and temps in about 50 degree weather.

 

I always set my pressure first thing in the morning before the sun hits them so that's not an issue. As I stated, I'm running with 112 psi and the max load is 120 psi. Any ideas?

[billr]

If it's a TST check your setting fior temp is set fior F not C.

 

I run GY G114 17.5" tires and on cool days like 50-60 out I only ever see 70 or so. Hot days like 80 I see mayber 100

 

If you are getting temps upwards of 150 that's not normal at all.

 

As far as setting up high and low pressure warn it's recommended to set low at about 15 psi below and 20 psi above your datum tire press setting that is set at around 68-70 F outside temp.

[ewacowboy]

Thanks Billr. It's a EEZ RV Tire system. It's been working fine until we purchased this new coach. The tow vehicle numbers are fine, so I'm sure it's not the monitor. I was just reading the manual again and the factory default temperature settings are at 158 and I was getting alarms on the coach tires when we pulled it home....

 

We're getting ready to hit the road again so I think I'll increase the psi to 120 on the coach and see if that makes a difference. If yours are running those temps then I have something to compare to.

 

Not sure what else to try at this point.

[Ronbo]

If you are starting st 125 psi then 158 is only a 33 psi increase. Not that much. I have never blown a tire, only peeled the tread off.

[billr]

If you are starting st 125 psi then 158 is only a 33 psi increase. Not that much. I have never blown a tire, only peeled the tread off.

He said he gets Temps over 158 that's way abnormal. I have never seen temps over 128 on the hottest of days.

 

Press generally goes up about 12% average. So starting at 125 psi would average rise to around 140 psi. A bit higher on very hot days. Also is running higher speeds. Say over 65 like 70 plus

 

Since the Tow vehicle numbers seem normal it does make sense the trailer sensors should be working.

 

I suggest to get to the bottom of the temp concern you use an infrared temp gun at a stop and check all tires and log them. All four trailer tires should be reasonably close. These readings will not relate to the TPMS readings because it measures Air temp. So there may be a relation in general but don't expect the same numbers at all. They likely will be higher with the gun.

 

Check the tread, edges, wheel and hub. That way you can see what's happening.

 

After a few times you should see what's going on.

 

Also do the truck. I do this on most stops as well just a quick check looking for odd man out.

 

If you have not weighted the trailer tires by individual wheel you really should run the psi max press as shown on sidewall until you know what your heaviest tire is and then decide to reduce the pressure according to a chart. This press will be set on all trailer tires based on heaviest.

 

I am not familiar with your TPMS so I can't comment on its performance. You could call the mfg with the facts once you get them.

 

Good luck hope this helps a bit.

[Jack Mayer]

Same as Bill. My G114's run very cool - about like his. And I am 6 tires on a 28K+ lb trailer. I drive at 65 or less.

[Alie&Jim's Carrilite]

The only time I have ever seen tire temps go that high was from a bearing failure. So if all 4 of your tires are reacting the same with your sensors and monitor, then the fault may be with the sensors.

Can you swap some of the truck and RV sensors? See if the issue stays with the tire or moves?

Were the tires balanced with "Beads"? (Dyna Beads is a popular brand of ceramic balancing beads). They can clog a tire stem and confuse the sensor.

Last would be Does your DRV have the MoRyde IS suspension or?

Have you had the alignment checked?

If the tire is out of alignment, the scrubbing action will create heat, damage tires, and eventually cause a blowout.

[Ronbo]

I think he may have meant pressure. Hopefully he will clearify.

[ewacowboy]

All good info and thanks to all. At this point I have set the psi to 120 on all four tires and will monitor closely. My plan is to set all four coach sensors to 120 with a high limit at 144 and a low limit at 108. I will leave the temperature setting at factory default (158) and see what happens. We are scheduled to get on the road in a week so will update at that time. If I have the same high readings again I will attempt to swap a couple of sensors and see if that makes a difference.

[Ray,IN]

Well then I've got a problem...my tow vehicle tires run about that temp as did my old Continental HTL2 Eco's, but these new Goodyear G114 run A LOT hotter than that. I had to increase the high limit on both psi and temperature. It's been sitting for a few months now so I can't recall exactly where I had to set it, but seems that they were running above 150 degrees while the 22.5s were running at about 85 degrees. All four Goodyears were running similar psi and temps in about 50 degree weather.

 

I always set my pressure first thing in the morning before the sun hits them so that's not an issue. As I stated, I'm running with 112 psi and the max load is 120 psi. Any ideas?

That is one sign of excessive sidewall flexation, which is caused by under-inflation. All tandem axles place tremendous stress on tire sidewalls, thus the recommendation to run trailer tires at sidewall-listed pressure.

FWIW, NO tire mfgr. recommends running less air pressure than what is stated on the federal tire placard in/on the vehicle. In fact, Michelin and Goodyear state this on their respective websites.

This from Goodyear RV tire website:

"IMPORTANT: It's a common practice for RV owners to lower tire pressure in their search for a smoother ride. This is not only dangerous, it's relatively ineffective, as the difference in ride quality is not significant".

[accumack]

Get your weight checked I think you are probably overweight. Our motorhome was delivered over weight on the front due to a manufacturing change. The front airbags were replaced and tires changed to a larger size. Prior to the changes temps and pressures increased to near maximums. After the correct tires for the load my tires never get anywhere close. By the way I will never believe the factory weights and will have my RV weighed. Just my $.02

[ewacowboy]

Actually put on my glasses and the sidewall states max load is 125psi.....oops. Guess I'll air them up to 125 and see how it goes.

[GeorgiaHybrid]

^{We currently have a DRV 38RSSA Elite that has been weighed multiple times. If you have a gen set in the front and the normal assortment of clothes, pots, food, etc on board, you are going to be right at 8K on the axles and between 4K and 5K on the pin. Ours has a GVWR of 21K and even though we are not fulltimng, we are right at that weight.}

[ewacowboy]

Well we got on the road and found that 125psi cold the coach tires would run UP TO 152psi (usually around 146) and temps around 92 degrees max.  Those were my maximums.  Outside air temps were around 80 degrees and speed set at 65 mph.....so if that sounds typical I guess we're okay.  My guess is I was under inflated to start with.

[Chad Heiser]

TST recommends setting alarm points for inflation increase at 120% of cold PSI and decrease at 90% of cold PSI, so you are right at the max end of that ballpark.

[Tireman9]

Did a blog post just on this topic of TPMS settings.

[BLK-9]

On 3/21/2017 at 7:40 AM, ewacowboy said:

Well we got on the road and found that 125psi cold the coach tires would run UP TO 152psi (usually around 146) and temps around 92 degrees max.  Those were my maximums.  Outside air temps were around 80 degrees and speed set at 65 mph.....so if that sounds typical I guess we're okay.  My guess is I was under inflated to start with.

Good to know my G114 are running similiar high PSI as yours. I set my cold PSI at 125 on all four tires. During our recent trip to IN and TN, my high PSI was ~145. We are headed to LV, NV during May timeframe, i am guessing i can see high PSI up to 150+ like yours. Thanks for sharing your information