Rear SRW tire pressure towing 5'er???

[Racechaser]

What's everyone running in the rears when towing with SRW's??

 

[JThiessen]

I run 75 in the rears, 65 in front (8K 5'er)

 

[dremelts]

Our 5er is about 6500 lb loaded. I run 70psi in the rear and 65 in the front when towing. When not towing I drop the rear down to 45-50 psi (if you don't reduce the tire pressure you will wear the center of the tread).

 

[TRLRTRSH]

80# in the rear, drive axle 5,840# GCW 20,360###

 

[DPelletier]

When running at or near the tire's max rating, its best to run max pressure - 80psi is my vote. Tire will run cooler and have less chance of a heat related failure.

I used to run my SRW at; loaded = 70 front, 80 rear

unloaded = 65 front, 55 rear



Dave

 

[klenger]

Based on the chart on the last page of this document http://www.klenger.net/dodge/3rd-gen-reference/2004-tire-inflation-pressures.pdf, I run 60 lbs front and rear. According to the notes on page 1 (High Speed Pressures Truck Type Tires), add 10 lbs for sustained high speed (over 65 mph). According to the table on the last page, with 50 lbs, each tire can carry 2470 lbs. , or 9880 lbs for all four. My GVWR is 9900, so I'm withing 20 lbs of the GVWR. I add 10 lbs to the 50 lbs per the previous note for 60 lbs all the way around. With my 5er connected, my front and rear axles are about equally loaded. 60 lbs is a nice easy number to remember, and running the same pressure front and rear makes it easier for rotating tires and using the spare.

 

[Racechaser]

Wow, lots of differences of opinion. Ken, I always thought a higher pressure would allow the tire to run cooler as well. Does 60psi accomplish that? I read the sidewall on the BF's and the max load is at the max pressure of 80psi, and I think that may be a little excessive.

 

[RHamner]

Towing my fifth (10300# on scales) I have settled on 65 front and 70 rear. I have found I need to drop to 40# rear when empty to avoid center tire wear. I constantly feel the rear (tires) when loaded as I stop to make sure I have no heat buildup.

 

[Midnite]

Originally posted by Racechaser

Wow, lots of differences of opinion.

What people are failing to mention is whether they run load range D tires, or load range E tires. The Ds have a max sidewall pressure of 65psi, and the Es are 80.



If someone swears up and down that you should run 80psi when loaded, but doesn't mention that that's only for load range E tires, and you happen to run Ds, you could be in for a nasty surprise by running 80psi.

I read the sidewall on the BF's and the max load is at the max pressure of 80psi, and I think that may be a little excessive.

Those are load range E tires, and 80psi isn't excessive at all for them. (unless maybe you meant ride quality)



When my truck is loaded, I pump everything up to the max sidewall pressure. The tires run cooler because of less sidewall flex, and I don't mind the difference in ride.



Mike

 

[TRLRTRSH]

Mike, good point, did not think to add my "03" tires are load range E.



Bill

 

[Racechaser]

Thanks Mike, all the previous posts make sense now. I'm running the "E's" and will do the same as you.

Matt

 

[irachar]

Weigh the rig at a truck stop, then put in the pressure shown on the chart. Tires will run cool and wear evenly. when empty I go all the way to 36 in the rears.

 

[DPelletier]

Stock tires are load range E's and personally, I wouldn't run D's on a truck I intend to load up to GVWR. Max tire pressure gives you cooler running tires which equal less chance of a blowout and also helps with mileage. Sway control is another reason to run at max pressure, although that's more important to me with my top-heavy slide-in than it is to you fifth wheel guys. The only two reasons to run at lower pressures are 1) ride and 2) to adjust for even treadwear. The ride is not a concern to me when loaded. rides fine. and the treadwear is a non-issue in my application as well, because 90 percent of the time, I'm running empty and can adjust the tire pressure to whatever is needed.



It's mostly a personal choice issue based on what your needs are. The advice in this thread would have you use between 60 and 70 on the fronts and 60 and 80 on the rears. If you took the middle ground and went 65 on the front and 70 on the rear, I think you'd do just fine. That having been said, if I still had my SRW, there's no way I'd run the rear tires at less than 80psi with my camper on.



Cheers

Dave

 

[klenger]

I fixed the link in my previous post.



Based the table at the link in my previous post, I am operating at the correct tire pressure up to the max GVWR of my truck. 60 lbs seems to be a good compromise between running empty and max load, and don't see any need to go any higher at this time.

 

[Midnite]

Originally posted by RHamner

I constantly feel the rear (tires) when loaded as I stop to make sure I have no heat buildup.

I missed this one earlier--this is a great idea and I do it myself on trips, regardless of load.



Mike

 

[DBF]

Originally posted by irachar

Weigh the rig at a truck stop, then put in the pressure shown on the chart. Tires will run cool and wear evenly. when empty I go all the way to 36 in the rears.

Amen!



DBF

 

[CajunDieselMan]

I run 70 psi rear and 50 psi front--judging from these posts, maybe I need to raise my front pressure--I'm running around 10,000# on my 5th wheel, hitch weight about 1,800. Thanks guys.

 

[jimnance]

Originally posted by Racechaser

What's everyone running in the rears when towing with SRW's??

Running the tires at or near max rating will never really hurt you. It's possible you'll get a little extra crown wear and the ride may not be as nice, but when towing heavy you don't want a failure.



Under inflation is the most common cause of tire failure. Sidewall flex causes a lot of heat, and it's the heat that kills the tires.



I'm right at 6,000 lbs on the rear axle, but have load range F (3600 lb rating) tires. They are speced for 90 PSI and I run 85 PSI when towing. The sidewalls on these tires are really stiff, and the extra capacity makes me feel better about towing heavy.

 

[Racechaser]

Thanks

Thanks for all the responses. Went with 65 in the front and 75 in the rears. Will be my first tow tonight with this truck, can't wait, is it time to go yet?? Oo. Oo. Oo.

Matt

 

[DPelletier]

Have fun!







Dave