Towing w/the Rebel and Duratracs

[mywifelovesme]

I took my TT to the shop the other day for some warranty work. And thinking that since I have E load tires, I should inflate them to almost max for towing. It was the worst experience of my life towing the TT (I have towed it over 1K miles before with a Silverado on P metric tires at 38PSI and the truck never moved around). White-Knuckled the whole time and I one point I spun the tires taking off from a stop light with the trailer hooked up. Granted it was raining but still...
So I started researching tire pressures while towing and read tons of threads on inflation. What I found for the most part. A majority of posters said inflate the tires to the max PSI (or really close to) for towing. That is great and all until I started researching more. The Rebel has Duratrac E load tires. Each tire at max inflation can hold a weight of 3300(and something)lbs. That would mean per axle the tires can hold 6600 lbs. The problem is the GAWR on front is 3900 and on the rear 4100 lbs on the Rebel. So as you can see you don't need 6600 lbs for either axle. Also the door jam sticker says cold psi should be 55psi for the front and 45 for the rear (and yes it is specific to the tire size on my truck). So I found an interesting post about inflation, tire contact patch and weight, sorry I don't remember where. Here is what is said...

Let's say we have a 5,000lb vehicle where the owner's manual recommends 35 PSI for normal operation. Based on that alone, 5,000 (pounds) / 35 (pounds/ square inch) = a contact patch of ~143 square inches. In other words:
Weight/ PSI = ContactPatch
If we load up 1,000 pounds of tongue weight, we want a tire PSI that gives us the same contact patch we had with no load. To find this, we simply re-arrange our formula with the new weight and original contact patch:
PSI = (new)Weight/ ContactPatch
This gives us 6,000 lb/ 143 = 42 PSI to match the original contact patch.
Note that every vehicle has a different weight distribution, etc. but for a very rough estimate on how to match what the manufacturer recommends as you increase load, that should help.

I am just using the rear for my example... What I did when I put 70 PSI in the rear was reduce the contact patch of my tires from the original set by Ram. Here were my calculations for the rear PSI:
Let's say my truck weighs 5776 ( for the sake of math I took the GVWR 7100-payload 1324 (I plan on actually weighing it on CAT scales this weekend). Based on Ram's recommendation for the tire PSI (45), I took 5776 divided by 45. That gave me a contact patch of 128.35 sq inches. I added 600 lbs of tongue weight...5776 + 600=6376. Divide 6376 by 128.35 to get 49.676 (PSI)...rounded up to 50 since my tire gauge doesn't read decimals).

When I inflated my tires to 70 PSI here is how the numbers look... 5776 divided by 70 = 82.5 sq inches (new contact patch) which is significantly lower than 128.35. That explains why the truck was all over the road (yes I have a WDH and it is set up properly). It was riding on doughnut tires essentially. Needless to say my inflation was reduced to 50 that night. I pick up the TT tomorrow from the shop and will update the towing feel. I thought this might help others who tow. If I am wrong somewhere in my logic and numbers someone kindly correct me but I won't ever increase my tire PSI back to 70 to tow a 6k trailer. It really was a horrifying experience for me.

 

[hutchman]

Tire manufacturers have tables/charts that give you max tire loading for a given pressure. As long as you are at or above this recommended pressure for your load, you will not damage your tires. I believe your thoughts on contact patch affecting handling, is spot on.

 

[mywifelovesme]

Thank you. I towed it 90 miles today with the 50PSI in the rear. Night and day difference even in the high winds.

 

[RaysFanBoy]

Good to know. Thanks for the detailed explanation.

 

[Rebel 12]

I took my TT to the shop the other day for some warranty work. And thinking that since I have E load tires, I should inflate them to almost max for towing. It was the worst experience of my life towing the TT (I have towed it over 1K miles before with a Silverado on P metric tires at 38PSI and the truck never moved around). White-Knuckled the whole time and I one point I spun the tires taking off from a stop light with the trailer hooked up. Granted it was raining but still...
So I started researching tire pressures while towing and read tons of threads on inflation. What I found for the most part. A majority of posters said inflate the tires to the max PSI (or really close to) for towing. That is great and all until I started researching more. The Rebel has Duratrac E load tires. Each tire at max inflation can hold a weight of 3300(and something)lbs. That would mean per axle the tires can hold 6600 lbs. The problem is the GAWR on front is 3900 and on the rear 4100 lbs on the Rebel. So as you can see you don't need 6600 lbs for either axle. Also the door jam sticker says cold psi should be 55psi for the front and 45 for the rear (and yes it is specific to the tire size on my truck). So I found an interesting post about inflation, tire contact patch and weight, sorry I don't remember where. Here is what is said...

Let's say we have a 5,000lb vehicle where the owner's manual recommends 35 PSI for normal operation. Based on that alone, 5,000 (pounds) / 35 (pounds/ square inch) = a contact patch of ~143 square inches. In other words:
Weight/ PSI = ContactPatch
If we load up 1,000 pounds of tongue weight, we want a tire PSI that gives us the same contact patch we had with no load. To find this, we simply re-arrange our formula with the new weight and original contact patch:
PSI = (new)Weight/ ContactPatch
This gives us 6,000 lb/ 143 = 42 PSI to match the original contact patch.
Note that every vehicle has a different weight distribution, etc. but for a very rough estimate on how to match what the manufacturer recommends as you increase load, that should help.

I am just using the rear for my example... What I did when I put 70 PSI in the rear was reduce the contact patch of my tires from the original set by Ram. Here were my calculations for the rear PSI:
Let's say my truck weighs 5776 ( for the sake of math I took the GVWR 7100-payload 1324 (I plan on actually weighing it on CAT scales this weekend). Based on Ram's recommendation for the tire PSI (45), I took 5776 divided by 45. That gave me a contact patch of 128.35 sq inches. I added 600 lbs of tongue weight...5776 + 600=6376. Divide 6376 by 128.35 to get 49.676 (PSI)...rounded up to 50 since my tire gauge doesn't read decimals).

When I inflated my tires to 70 PSI here is how the numbers look... 5776 divided by 70 = 82.5 sq inches (new contact patch) which is significantly lower than 128.35. That explains why the truck was all over the road (yes I have a WDH and it is set up properly). It was riding on doughnut tires essentially. Needless to say my inflation was reduced to 50 that night. I pick up the TT tomorrow from the shop and will update the towing feel. I thought this might help others who tow. If I am wrong somewhere in my logic and numbers someone kindly correct me but I won't ever increase my tire PSI back to 70 to tow a 6k trailer. It really was a horrifying experience for me.

Thanks for the info. I had the same problem. I keep readjusting my WDH because swaying around on the road. I was thinking it was because the tires are a softer off road tire then I'm used too.

 

[rudyyoko]

Thank you. I towed it 90 miles today with the 50PSI in the rear. Night and day difference even in the high winds.

What did you have the front tires set at when the rears were set at 50 psi

 

[mywifelovesme]

What did you have the front tires set at when the rears were set at 50 psi

I left the front at 55 since my WDH keep the weight mostly the same on the front axle.

 

[adboyd06]

55 PSI for the front seems excessive on a half ton with E rated tires. Do you agree? Have you done the chalk test to test contact patch?

 

[CornTrucks]

I’m not sure it’s ever necessary to change tire pressure for towing with a pickup. The only exception might be if you are doubling the towing limit or something like that. And even then, I don’t change my tire pressures and don’t have any issues.

I only vary tire pressures with tractors or combines, and that is just to reduce soil compaction.

 

[adboyd06]

I think you're right CornTrucks. After doing a bit of research most LT tires at 40 PSI will support the the GAWR of 4,100 pounds.

 

[mywifelovesme]

55 PSI for the front seems excessive on a half ton with E rated tires. Do you agree? Have you done the chalk test to test contact patch?

I just went off what is on the door sticker. 55 front/45 rear during normal driving. 55/50 for towing. It seems to work for me with my travel trailer.

 

[YngwieL]

I took my TT to the shop the other day for some warranty work. And thinking that since I have E load tires, I should inflate them to almost max for towing. It was the worst experience of my life towing the TT (I have towed it over 1K miles before with a Silverado on P metric tires at 38PSI and the truck never moved around). White-Knuckled the whole time and I one point I spun the tires taking off from a stop light with the trailer hooked up. Granted it was raining but still...
So I started researching tire pressures while towing and read tons of threads on inflation. What I found for the most part. A majority of posters said inflate the tires to the max PSI (or really close to) for towing. That is great and all until I started researching more. The Rebel has Duratrac E load tires. Each tire at max inflation can hold a weight of 3300(and something)lbs. That would mean per axle the tires can hold 6600 lbs. The problem is the GAWR on front is 3900 and on the rear 4100 lbs on the Rebel. So as you can see you don't need 6600 lbs for either axle. Also the door jam sticker says cold psi should be 55psi for the front and 45 for the rear (and yes it is specific to the tire size on my truck). So I found an interesting post about inflation, tire contact patch and weight, sorry I don't remember where. Here is what is said...

Let's say we have a 5,000lb vehicle where the owner's manual recommends 35 PSI for normal operation. Based on that alone, 5,000 (pounds) / 35 (pounds/ square inch) = a contact patch of ~143 square inches. In other words:
Weight/ PSI = ContactPatch
If we load up 1,000 pounds of tongue weight, we want a tire PSI that gives us the same contact patch we had with no load. To find this, we simply re-arrange our formula with the new weight and original contact patch:
PSI = (new)Weight/ ContactPatch
This gives us 6,000 lb/ 143 = 42 PSI to match the original contact patch.
Note that every vehicle has a different weight distribution, etc. but for a very rough estimate on how to match what the manufacturer recommends as you increase load, that should help.

I am just using the rear for my example... What I did when I put 70 PSI in the rear was reduce the contact patch of my tires from the original set by Ram. Here were my calculations for the rear PSI:
Let's say my truck weighs 5776 ( for the sake of math I took the GVWR 7100-payload 1324 (I plan on actually weighing it on CAT scales this weekend). Based on Ram's recommendation for the tire PSI (45), I took 5776 divided by 45. That gave me a contact patch of 128.35 sq inches. I added 600 lbs of tongue weight...5776 + 600=6376. Divide 6376 by 128.35 to get 49.676 (PSI)...rounded up to 50 since my tire gauge doesn't read decimals).

When I inflated my tires to 70 PSI here is how the numbers look... 5776 divided by 70 = 82.5 sq inches (new contact patch) which is significantly lower than 128.35. That explains why the truck was all over the road (yes I have a WDH and it is set up properly). It was riding on doughnut tires essentially. Needless to say my inflation was reduced to 50 that night. I pick up the TT tomorrow from the shop and will update the towing feel. I thought this might help others who tow. If I am wrong somewhere in my logic and numbers someone kindly correct me but I won't ever increase my tire PSI back to 70 to tow a 6k trailer. It really was a horrifying experience for me.

good info here.. mine were all set at 55 lbs whe i purchased my 2019 ram rebel.. I'll be towing a 6400 lb dry weight camper, so I am thinking the 55 lbs in the rear should be about right.. also have to take into consideration with this hot weather, the tires will probably gain 10-15 lbs.. and the max tires pressure is 80 lbs.. so I sure as heck dont want to exceed that..

 

[WXman]

I have LT-E tires and I run mine at 37 PSI. Door jamb says 32. My experience with Duratracs is that they weren't good in rain anyhow, so bumping pressures WAY up would be a terrible idea. 60 PSI is over kill on a truck with a 7,100 lb. GVWR. It could be argued that 50 PSI is overkill. All that's going to do is create a pogo stick effect, ruin your handling, and make your tires wear the center faster.

I think 40 PSI is probably a good compromise between ride quality, wear, and performance.

As noted, the MAX tire pressure on a tire is for the maximum capacity. Since these 1500 trucks can't get even remotely close to the maximum capacity of the four LT-E tires, we certainly don't need to be anywhere near maximum air pressure.

 

[shadoweng]

I took my TT to the shop the other day for some warranty work. And thinking that since I have E load tires, I should inflate them to almost max for towing. It was the worst experience of my life towing the TT (I have towed it over 1K miles before with a Silverado on P metric tires at 38PSI and the truck never moved around). White-Knuckled the whole time and I one point I spun the tires taking off from a stop light with the trailer hooked up. Granted it was raining but still...
So I started researching tire pressures while towing and read tons of threads on inflation. What I found for the most part. A majority of posters said inflate the tires to the max PSI (or really close to) for towing. That is great and all until I started researching more. The Rebel has Duratrac E load tires. Each tire at max inflation can hold a weight of 3300(and something)lbs. That would mean per axle the tires can hold 6600 lbs. The problem is the GAWR on front is 3900 and on the rear 4100 lbs on the Rebel. So as you can see you don't need 6600 lbs for either axle. Also the door jam sticker says cold psi should be 55psi for the front and 45 for the rear (and yes it is specific to the tire size on my truck). So I found an interesting post about inflation, tire contact patch and weight, sorry I don't remember where. Here is what is said...

Let's say we have a 5,000lb vehicle where the owner's manual recommends 35 PSI for normal operation. Based on that alone, 5,000 (pounds) / 35 (pounds/ square inch) = a contact patch of ~143 square inches. In other words:
Weight/ PSI = ContactPatch
If we load up 1,000 pounds of tongue weight, we want a tire PSI that gives us the same contact patch we had with no load. To find this, we simply re-arrange our formula with the new weight and original contact patch:
PSI = (new)Weight/ ContactPatch
This gives us 6,000 lb/ 143 = 42 PSI to match the original contact patch.
Note that every vehicle has a different weight distribution, etc. but for a very rough estimate on how to match what the manufacturer recommends as you increase load, that should help.

I am just using the rear for my example... What I did when I put 70 PSI in the rear was reduce the contact patch of my tires from the original set by Ram. Here were my calculations for the rear PSI:
Let's say my truck weighs 5776 ( for the sake of math I took the GVWR 7100-payload 1324 (I plan on actually weighing it on CAT scales this weekend). Based on Ram's recommendation for the tire PSI (45), I took 5776 divided by 45. That gave me a contact patch of 128.35 sq inches. I added 600 lbs of tongue weight...5776 + 600=6376. Divide 6376 by 128.35 to get 49.676 (PSI)...rounded up to 50 since my tire gauge doesn't read decimals).

When I inflated my tires to 70 PSI here is how the numbers look... 5776 divided by 70 = 82.5 sq inches (new contact patch) which is significantly lower than 128.35. That explains why the truck was all over the road (yes I have a WDH and it is set up properly). It was riding on doughnut tires essentially. Needless to say my inflation was reduced to 50 that night. I pick up the TT tomorrow from the shop and will update the towing feel. I thought this might help others who tow. If I am wrong somewhere in my logic and numbers someone kindly correct me but I won't ever increase my tire PSI back to 70 to tow a 6k trailer. It really was a horrifying experience for me.

I bought my travel trailer and drove it home 6 hours with 60 psi in front and rear tires. The camper dealership set up my WDH. Had just purchased the Rebel about a week prior and that was the air from the dealership. The 6 hour drive was no where near comfortable. I then went camping 3 hours from home and was very windy on that drive and was extremely uncomfortable. still 60psi in rear. After that trip I decided I needed to figure out some things. Since then I weighed the truck empty 5660 pounds. I weighed the truck and trailer was total of 13080 pounds which means camper was 7420 pounds. I installed a Hellwig rear sway bar and put in Airlift 1000 bags in the rear. I inflated my rear tires to 70 and went down the interstate. Slight sway at 55 then lots of sway at 60. Got off interstate and made adjustments to air pressure. Went down to 60 psi and was way better. 60 had no sway and 73 had slight sway. At this point i was at my exit. I plan on bringing the pressure on down to 50 like you were suggesting and maybe things will be right. I still have to some more weights with trailer hooked up to make sure my WDH is set up exactly right but I think the Lower pressure is right on.