Tire / rim inflation pressures

[BG1]

I am preparing to replace the OEM tires on my Rockwood 2608SB with new ones one load range higher. (D to E). The inflation psi for the new tires will be higher, and I’m concerned about the pressures being too high for the rims.
Can anyone tell me where I would locate recommended pressures for aluminum rims supplied with travel trailers? Or am I worrying needlessly?

[Larry-NC]

Originally Posted by BG1

I am preparing to replace the OEM tires on my Rockwood 2608SB with new ones one load range higher. (D to E). The inflation psi for the new tires will be higher, and I’m concerned about the pressures being too high for the rims.
Can anyone tell me where I would locate recommended pressures for aluminum rims supplied with travel trailers? Or am I worrying needlessly?

No reason to go with a higher pressure unless you were overloading with the prior tires. Too much air makes the ride harsher, will knock everything loose in your trailer.

[Bob K4TAX]

Go with the recommended tire pressure for the original tires. Although the new tires may be rated for a higher load, there is no need to increase air pressure over the original tires.

A tire pressure monitor (TPMS) is handy to have but a good one will set you back $300 to $500. Those $100 +/- units aren't worth the box they are packed in.

I use an infrared handheld thermometer and do a walk around during breaks. I check tire temperatures and brake hub temperatures. Our trailer originally had load range C tires inflated to 55 lbs. I upgraded to load range D and still inflate to 55 lbs.

Bob

[jeff64]

Check website for Lionshead rims. They are a major supplier

[Brother Les]

You will change tires to a higher rating (D to E)... Every tire Dealer that I have talked to says to go with what is 'on the tire psi'. The sticker that is on the side of your unit is for the OEM tires that came with the unit. After changing to a different tire rating, the sticker information is no longer valid. Under aired tires will run a lot hotter and have the potential of sidewall flexing and break down and tread separation. If you tell a Dealer that you went with the psi on the unit and not on the tire, the Dealer will tell you that the warranty is voided....


your rims will be fine with the higher psi



It is your unit....



Give https://www.etrailer.com/ a call and see what they suggest on psi.

[TitanMike]

Originally Posted by Brother Les

You will change tires to a higher rating (D to E)... Every tire Dealer that I have talked to says to go with what is 'on the tire psi'. The sticker that is on the side of your unit is for the OEM tires that came with the unit. After changing to a different tire rating, the sticker information is no longer valid. Under aired tires will run a lot hotter and have the potential of sidewall flexing and break down and tread separation. If you tell a Dealer that you went with the psi on the unit and not on the tire, the Dealer will tell you that the warranty is voided....


your rims will be fine with the higher psi



It is your unit....



Give https://www.etrailer.com/ a call and see what they suggest on psi.

The air pressure on the OEM sticker is determined by the tire SIZE and WEIGHT it's carrying. If size is still the same and weight is the same, changing load range does NOT require a tire pressure increase ( unless OEM tires were overloaded to begin with).

Tires that SHOULD be inflated to the pressure molded on the sidewall are usually carrying close to their max load to start with.

[NavyLCDR]

Every reputable tire dealer that I have talked to has stated to inflate the tires to the inflation pressure on the chart provided by the tire manufacturer for the GVWR of the trailer. And invariably, that is equal to the pressure listed on the sticker on the side of the trailer.

When you inflate the tire to that listed on the inflation chart using the GVWR of the trailer (divided by number of tires + 10%), you are not underinflating the tire. You are inflating it to the proper pressure.

Overinflated tires are more susceptible to damage from hitting objects in the road or curbs and they make the trailer more susceptible to damage as well, there is less contact across the tread area with the road which increases the chances of skidding during hard braking or skidding sideways on wet pavement, and it increases the wear of the tread in the center of the tire compared to the tread on the edges of the tire.

Some people don't like to admit that both vehicle manufacturers and tire manufacturers actually do know what the proper inflation pressures are for tires for a given weight. The only time the pressure on the sidewall of the tire is the proper inflation pressure is when the GVWR of the vehicle matches the weight limit on the sidewall of the tire.

And now the dissenting opinions will follow.

[NavyLCDR]

Castle Rock, 225/75R15, LR D, 65 PSI, 2540 lbs:



I move up to Goodyear Endurance, 225/75R15 LR E tire. What does Goodyear recommend for my unchanged weight of 2540 lbs? Interesting that it is 65 PSI also.



So why should I run the Goodyear Endurance tire, which is already going to have a stiffer sidewall than the Castle Rock, at 80 PSI? Just so I can beat my trailer up more with every bump in the road?

[BG1]

Thanks to you all for the replies and suggestions. The Castle Rocks that I retired, (manufactured in early 2017 for my 2018 Rockwood 2608SB), we’re very evenly worn, and had no lumps or bumps that indicated impending doom…I’m blessed ��!
The tire dealer did inflate the new tires to 80 psi, but I believe my next stop will be the CAT scales to assess the actual camping weight of the unit and adjust inflation accordingly.
I read the posts in this app all the time, and I’m very appreciative of your collective knowledge.
Thanks for the tips on the rim website, and the chart from Goodyear!
Oh, and Lieutenant Commander, thank you for your service sir! ��
BG1

[NavyLCDR]

If you inflate the tires to what matches the GVWR you'll be fine. And I'll bet you find that the inflation pressure on the inflation charts based on GVWR will be the same as shown on the sticker on the trailer. Underinflation is generally a worse condition than overinflation.

Weighing is always good, but as long as your actual weight is less than GVWR, tire inflation should be based on GVWR.

[PhilFromMaine]

Originally Posted by NavyLCDR

Every reputable tire dealer that I have talked to has stated to inflate the tires to the inflation pressure on the chart provided by the tire manufacturer for the GVWR of the trailer. And invariably, that is equal to the pressure listed on the sticker on the side of the trailer.

When you inflate the tire to that listed on the inflation chart using the GVWR of the trailer (divided by number of tires + 10%), you are not underinflating the tire. You are inflating it to the proper pressure.

Overinflated tires are more susceptible to damage from hitting objects in the road or curbs and they make the trailer more susceptible to damage as well, there is less contact across the tread area with the road which increases the chances of skidding during hard braking or skidding sideways on wet pavement, and it increases the wear of the tread in the center of the tire compared to the tread on the edges of the tire.

Some people don't like to admit that both vehicle manufacturers and tire manufacturers actually do know what the proper inflation pressures are for tires for a given weight. The only time the pressure on the sidewall of the tire is the proper inflation pressure is when the GVWR of the vehicle matches the weight limit on the sidewall of the tire.

And now the dissenting opinions will follow.

2X

[Brother Les]

All reasons put forth would indicate that you remain at the current load range D for your tires.....


just kidding.


Your rims will handle the higher load range E at a higher psi pressure. (Which was your question).



I believe that everyone goes beyond the recommended 'load range' of weight that is added to/on and in their units (water/food/stuff ect). Hence a higher tire range of E may be wanted, hence a higher psi for that added weight of 'stuff'.




Blessings

[5picker]

Originally Posted by Brother Les

You will change tires to a higher rating (D to E)... Every tire Dealer that I have talked to says to go with what is 'on the tire psi'. The sticker that is on the side of your unit is for the OEM tires that came with the unit. After changing to a different tire rating, the sticker information is no longer valid. Under aired tires will run a lot hotter and have the potential of sidewall flexing and break down and tread separation. If you tell a Dealer that you went with the psi on the unit and not on the tire, the Dealer will tell you that the warranty is voided....


your rims will be fine with the higher psi



It is your unit....



Give https://www.etrailer.com/ a call and see what they suggest on psi.

I will disagree...

Recommended tire pressures by every major manufacturer that I have read are for the load it is carrying, not the load range of the tire. The MAX sidewall pressure recommendation is just that, the maximum inflation for the maximum load the tire can carry.

To the OP... many wheels have MAX inflation ratings stamped on them. (usually on the inner rim) But unless you change tire sizes (not load ratings) or significantly are changing your R/V's weight, run them at the same recommended pressure for the weight of your R/V. That recommended pressure is on the decal/sticker of your R/V.

[Brother Les]

Originally Posted by 5picker

I will disagree...

Recommended tire pressures by every major manufacturer that I have read are for the load it is carrying, not the load range of the tire. The MAX sidewall pressure recommendation is just that, the maximum inflation for the maximum load the tire can carry.

To the OP... many wheels have MAX inflation ratings stamped on them. (usually on the inner rim) But unless you change tire sizes (not load ratings) or significantly are changing your R/V's weight, run them at the same recommended pressure for the weight of your R/V. That recommended pressure is on the decal/sticker of your R/V.

Load it is carrying.....

Why go to a higher 'load range' of tire, if the 'load' does not change?
Keep 'the load' the same as on the sticker and the tire the same and the psi the same. All is good.

[MR.M]

Another tire pressure load range debate .


If you go from an LRD to LRE you mare talking 15 psi difference rims won't care . the load limit of the rims my be an issue


If you stick with the 65 psi of the LRD's you gain no added cushion for weight and my guess it the LRD's were at minimum load capacity to begin with .
Going with the LRE's and increase psi will add much needed cushion to the max load weight of your trailer i would run min 75psi or even the full 80 psi for max capacity .
7 yrs with my TH that came with LRD grossly under rated for the TH. Went to LRE the fist month of owner ship always ran 80 psi and never had any issues

Everyone has an opinion on this some are stuck on what the book says some give opinion based on real life and not just a graph on paper

[NavyLCDR]

People who want to increase the weight capacity of their trailers by moving up in load range on their tires only are driving down the wrong road. There are many other components involved in setting the GVWR for the trailer, and the tires are probably the smallest and last part part of that equation.

If you are exceeding GVWR of the trailer, the answer is to leave stuff behind, not to just bump up air pressure on the tires.

Yes, I am stuck on what the book says because that book was written for a reason. And the average trailer owner is not qualified to safely make changes to the book. Again, believe it or not, tire and vehicle manufacturers do know what they are doing.

[NMWildcat]

Originally Posted by NavyLCDR

People who want to increase the weight capacity of their trailers by moving up in load range on their tires only are driving down the wrong road. There are many other components involved in setting the GVWR for the trailer, and the tires are probably the smallest and last part part of that equation.

If you are exceeding GVWR of the trailer, the answer is to leave stuff behind, not to just bump up air pressure on the tires.

Yes, I am stuck on what the book says because that book was written for a reason. And the average trailer owner is not qualified to safely make changes to the book. Again, believe it or not, tire and vehicle manufacturers do know what they are doing.

I don't see where anyone was talking about trying to increase the load capacity of their RV with tires or exceed the weight rating of their RV.
I will agree that manufacturers do know what they are doing, but it is definitely not for the good of the consumer. Most towables I see come with tires minimally meeting the load they are expected to carry. It doesn't help that they are also usually the cheapest tires available. This is one reason why we see so many tire failures.
My own experience is an example of one I have seen countless times among my RV friends. My fifth wheel is usually around 11.6k fully loaded. Yep, I have a scale available at the farm. I am anal about tire pressure. So I always check tire pressure before each travel day starts. I kept the ST235/80R16E tires at the sticker recommended 80psi which is also the max cold psi on the tire. At 18 months I had 3 of the OEM tires fail on one trip. Replaced with Maxxis of the same size and LR. Had better luck, but at 2 years had another failure on the road.
Replaced with the same size tires but a LR G. I run these at 88psi (max cold psi of 110) and have had no problems. On my second set now.
Going up a LR usually gives you a better tire with more plys. The tire performs much better with no noticable sway. I have ample cushion in load capacity.
As far as the higher psi and LR 'shaking my RV to pieces', I see no evidence of that. Perhaps a much lighter RV might see more road shock if you increase psi, but in a 12k RV, I doubt it seriously.
So no, I don't blindly trust RV manufacturers whose main focus is the bottom line. Going up a LR can be a very good and safe upgrade.

[Bob K4TAX]

Originally Posted by Brother Les

All reasons put forth would indicate that you remain at the current load range D for your tires.....

just kidding.

Your rims will handle the higher load range E at a higher psi pressure. (Which was your question).

I believe that everyone goes beyond the recommended 'load range' of weight that is added to/on and in their units (water/food/stuff ect). Hence a higher tire range of E may be wanted, hence a higher psi for that added weight of 'stuff'.


Blessings

Usually, the axle(s) rating will be the key factor in the maximum load the trailer can carry. Increasing the load range of the tires does not change the axle ratings.

As to rims, don't forget the maximum recommended pressure rating of the valve stem. I recall the rubber ones top out at 65 lbs max pressure, while the metal ones will go significantly higher. I've not recently researched the point.

Bob

[NavyLCDR]

Originally Posted by NMWildcat

I don't see where anyone was talking about trying to increase the load capacity of their RV with tires or exceed the weight rating of their RV.
I will agree that manufacturers do know what they are doing, but it is definitely not for the good of the consumer. Most towables I see come with tires minimally meeting the load they are expected to carry. It doesn't help that they are also usually the cheapest tires available. This is one reason why we see so many tire failures.

My trailer, for example, has a GVWR of 5,860 lbs. On the scales I am at 4,920 on the trailer axles and 800 lbs tongue weight. It came from the factory with Trailer King RST load range D tires, and sticker inflation recommended is 65 PSI.

If I moved up to Load Range E tires, would there be any legitimate reason to inflate them to 80 PSI, instead of the recommended 65 PSI?

[Brother Les]

Originally Posted by NavyLCDR

My trailer, for example, has a GVWR of 5,860 lbs. On the scales I am at 4,920 on the trailer axles and 800 lbs tongue weight. It came from the factory with Trailer King RST load range D tires, and sticker inflation recommended is 65 PSI.

If I moved up to Load Range E tires, would there be any legitimate reason to inflate them to 80 PSI, instead of the recommended 65 PSI?

The tire Load Range E tire is made for a heavier (cough) Load Range. The psi is recommended at (cold) 80 psi. Under inflating the tire will put more pressure on the sidewalls as it will slightly bulge more. Bulging sidewalls will allow more tread on the pavement surface and heat up the tire and tread. Over time you may gater this under psi/over heated tire.