Tire Pressure Question

[Texdan]

The CAT scale would give you weights for both the steer (front) and drive (rear) axles. You would divide each of those weights by two to get the weight on each wheel. The only "harm" from running over-inflated is, as I said, abnormal wear in the center of the tire. If there is a truck tire shop near you, they could probably look at your truck and tires and give you some good advice. It will be good to have CAT scale weights for your rig - both hitched and unhitched - to know what you actually have. BTW - your 29RS fully loaded will likely put somewhere around 2,640 lbs. on the pin (23% of GVWR).

Rob

Not sure why you say I'm running them overinflated when the tire max is 80#? My GVWR is 10995 so 23% would be 2530. Dry weight is about 9100, we won't be hauling any water in our tank so I'm 'guessing' we'll be at 10k max. Then again I know how stuff can add up and won't really know until hitting a CAT scale. Wondering where the 23% figure comes from? Also, can you tell me how to weigh at a CAT scale, I've seen some posts but can't find them right now. Thanks.

Update: So it looks like 1st weigh would be front/rear/trailer on the 3 scales. To get the 'unhitched' weights do you then just raise the trailer off of the pin while sitting on the scale making sure the trailer stabilizers are on the back 3rd scale?

[Texdan]

Well, picked up my Reflection 29RS yesterday for my first ever fiver tow. I put front tires (80# max Michelin E) at 70 front and 80 back. Truck sticker on stock 17" E is 65 front 80 back. Anywho, I am a little disappointed in that I seem to get a little chucking while driving with my 2013 Chevy 2500HD Duramax. I have a graphite plate on the pin box and greased the hitch jaws and put white lithium grease on the hitch base rubber thingies where the hitch head sits. Any ideas or is that normal? My thoughts:

1. Harder ride due to tire pressure?
2. Would truck air bags eliminate this?
3. ?????

Other than that we are already loving the fiver even in the driveway!

[jkwilson]

Well, picked up my Reflection 29RS yesterday for my first ever fiver tow. I put front tires (80# max Michelin E) at 70 front and 80 back. Truck sticker on stock 17" E is 65 front 80 back. Anywho, I am a little disappointed in that I seem to get a little 'jerking' while driving with my 2013 Chevy 2500HD Duramax. I have a graphite plate on the pin box and greased the hitch jaws and put white lithium grease on the hitch base rubber thingies where the hitch head sits. Any ideas or is that normal? My thoughts:

1. Harder ride due to tire pressure?
2. Would truck air bags eliminate this?
3. ?????

Other than that we are already loving the fiver even in the driveway!

Chucking is kind of mysterious, but my recommendation is not to waste any effort resolving it until you have the rig loaded for camping and are sure the hitch and pin box are set where you want. Weight distribution can make it better or worse.

Obviously, check that your hitch is secure and working properly.

There are pin boxes that can reduce the effect, but like I said, get the rig ready to use before going down that road.

[Texdan]

Chucking is kind of mysterious, but my recommendation is not to waste any effort resolving it until you have the rig loaded for camping and are sure the hitch and pin box are set where you want. Weight distribution can make it better or worse.

Obviously, check that your hitch is secure and working properly.

There are pin boxes that can reduce the effect, but like I said, get the rig ready to use before going down that road.

Thanks, she's almost fully loaded so I will be finding out in a few days. So sounds like chucking can be a normal thing?

[Malco1]

Well, picked up my Reflection 29RS yesterday for my first ever fiver tow. I put front tires (80# max Michelin E) at 70 front and 80 back. Truck sticker on stock 17" E is 65 front 80 back. Anywho, I am a little disappointed in that I seem to get a little chucking while driving with my 2013 Chevy 2500HD Duramax. I have a graphite plate on the pin box and greased the hitch jaws and put white lithium grease on the hitch base rubber thingies where the hitch head sits. Any ideas or is that normal? My thoughts:

2. Would truck air bags eliminate this?

Other than that we are already loving the fiver even in the driveway!

I put Timbren's on my F250 they made a tremendous difference. They are much cheaper than airbags, and only come into play when needed.

[JessJoe4168]

I have weighed my truck with and without my 29RS. I have used the Firestone tire rating chart to tell me I should run 65 psi empty on the Ram rear axle. But, the Ram TPMS does not like 65 and alerted me all the time. I just went back to 80 and the Ram system was satisfied.
Also, I have a Reese Goose Box hitch and run 42 psi in the air bag and the 29RS tires at 65 psi. I monitor tire temp and pressure and temp with a BellaCorp TPMS. I check tire, axle hub and drum temps when I stop for a break. i am looking for major deviations in temps as a sign for impending issues.

[GeoffnCheri]

Picking up my new Reflection 29RS fiver with GVWR of 11k and 9100 dry tomorrow. I have a 2013 Chevy 2500HD Duramax with Michelin 18" tires, max pressure rating 80lbs. I normally kept them at 70# when pulling my 7k bumper pull. Should I take the tires up to the max 80# since I'll have an additional 2500-4000#?

I run 18" tires on my F-250. 65 psi front and rear gives me the best ride. YMMV

[Spike32]

Picking up my new Reflection 29RS fiver with GVWR of 11k and 9100 dry tomorrow. I have a 2013 Chevy 2500HD Duramax with Michelin 18" tires, max pressure rating 80lbs. I normally kept them at 70# when pulling my 7k bumper pull. Should I take the tires up to the max 80# since I'll have an additional 2500-4000#?

I have a 2002 Sierra 2500HD pulling a 9,000 lb 2970RL. I always run the rear tires at 80 lbs when towing (per the door sticker), with fronts at 70. Any time you are carrying a load of 80% or more of the GVWR you should use the recommended max inflation.

[Cdburgerjr]

I’m adding to this thread to ask for more clarity, if I may. I will be grateful for more education. I’ve been googling a bit on tire load tables and I think what I’ve found makes sense. Although, the general advice of “just do what the sticker says” becomes unsatisfying when I realize (and see how) the sticker number is set according to the GAWR number, which would be overinflated if I’m less than the max weights.

According to my reasoning below, I think I would set my tires at 40 PSI front, 50 PSI rear, for a tire that says 80 PSI on the sidewall at maximum weights. Am I doing it right?

My truck doesn’t have the yellow tire load sticker, but the VIN configuration sticker shows PSI that matches the table at tirepressure.com for the tire at the GAWR. Running both axles at GAWR would go over the GVWR by 50%. The OEM tire was LT265/75R16E. The PSI on the sticker are 55/70.

Here are my questions:

My current tire is LT285/75R16E, which has quite a bit more load capacity for the same PSI (12% more at 50 PSI). If I look up the chart by my actual CAT scale weight, with camper on the truck, I get surprisingly low PSI answers.

Front Axle: 3960 or 1980# per tire
This falls off the bottom of the chart at 2130# and 35 PSI. The GAWR would be b/t 35 and 40.

Rear Axle: 4700 or 2350# per tire
This lands on the chart at 2340# 40 PSI. The GAWR would be b/t 55 and 60.

If I add 10% to actual weights (for 2178 and 2585) and “round up” on the table, I end up with 40 PSI for front wheels and 50 PSI for rear wheels.

Would 40/50 be the numbers you would go with? Do I use the tables correctly?

Setting all the tires to 80 PSI would be preparing them for 15000# of load (3750x4), which is 70% over the truck’s 8800 GVWR. That all seems to make sense.

I used the chart at https://tirepressure.com/lt285-75r16-tire-pressure

[Hoopy Frood]

JMO of course, but I don't think I would go that low with a load. The lower the pressure with a load, the more the tire will flex, the more the tire flexes the more heat it produces. Heat is a tire's enemy. But as I said, I'm no tire engineer, JMO.