Good Sam Club Open Roads Forum: Towing: Question about tires
Open Roads Forum Already a member? Login here.   If not, Register Today!  |  Help

Newest  |  Active  |  Popular  |  RVing FAQ Forum Rules  |  Forum Posting Help and Support  |  Contact  

Search:   Advanced Search

Search only in Towing

Open Roads Forum  >  Towing

 > Question about tires

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 6  
Prev
BenK

SF BayArea

Senior Member

Joined: 04/18/2002

View Profile



Posted: 09/08/20 07:49pm Link  |  Quote  |  Print  |  Notify Moderator

There is a difference in tire classes, but since am not a tire engineer...don’t know the details in specifications

But...the fact that “P” class used on pickups/SUVs, has the RMA recommend their sidewall weight carrry information be reduced by 9%. Whereas “LT” class does not need to have it’s sidewall weight carry rating reduced...indicates a significant difference...or a 9% difference...

My guess is that there are either higher strength materials, more of it and the construction somehow different in some way.

Also, why the exact same OEM, model, size tire...but...the only difference being “P” class vs “LT” class will have the “LT” cost more and weigh more than the “P” class tire


-Ben Picture of my rig
1996 GMC SLT Suburban 3/4 ton K3500/7.4L/4:1/+150Kmiles orig owner...
1980 Chevy Silverado C10/long bed/"BUILT" 5.7L/3:73/1 ton helper springs/+329Kmiles, bought it from dad...
1998 Mazda B2500 (1/2 ton) pickup, 2nd owner...
Praise Dyno Brake equiped and all have "nose bleed" braking!
Previous trucks/offroaders: 40's Jeep restored in mid 60's / 69 DuneBuggy (approx +1K lb: VW pan/200hpCorvair: eng, cam, dual carb'w velocity stacks'n 18" runners, 4spd transaxle) made myself from ground up / 1970 Toyota FJ40 / 1973 K5 Blazer (2dr Tahoe, 1 ton axles front/rear, +255K miles when sold it)...
Sold the boat (looking for another): Trophy with twin 150's...
51 cylinders in household, what's yours?...

BackOfThePack

Fort Worth

Full Member

Joined: 08/03/2020

View Profile


Offline
Posted: 09/09/20 05:46am Link  |  Quote  |  Print  |  Notify Moderator

TurnThePage wrote:

CapriRacer wrote:

MFL wrote:

The door sticker is for best ride, but for towing heavy, you need to air up to get full use of tire load capability. Like mentioned full pressure in rear, and try about 42 in the front. A bit of trial, to know what handles best, after all hooked up and towing.

Jerry


Nope! That's not right.

The inflation pressure on the sticker on the door frame includes the max load (GAWR's) and unless specified otherwise, includes the towing limitations published by the vehicle manufacturer.
That may be technically accurate, but I know from plenty of experience that airing the tires up closer to their max, yields a significantly safer and more stable ride. My Ram 1500 recommends 41 PSI on both axles, which IS enough for stable and safe towing.


Put the tires to the value stated in the Load & Pressure Table (and vehicle manufacture range) according to Cat Scale axle readings. .

More than necessary DOES NOT make for better steering, handling or braking. . That problem is addressed by improving the pickup. Better shocks, polyurethane anti-roll bar bushings and a rear Panhard Rod. (HENDERSON'S LINE UP for a rear Trac Bar).

(Where a rear anti-roll bar doesn’t exist, choose the smallest. But upsize the front is then a requirement).

Using more tire pressure than NECESSARY to counter movement of the body against the suspension only makes loss-of-control MORE likely.

Dead-wrong approach.

Some sidewall movement flattens the edge at which tires lose their grip with tall aspect LT tires for given steering inputs. A warning. Weight-adjusted pressure IS the target.

Incorrect hitch rigging is the usual BAD BASELINE. Over inflating tires on top of that only makes a bad situation worse. But is the norm.

This is yet another aspect of using a Hensley-patent hitch. The trailer stays in CONSTANT alignment with the tow vehicle until TV steering inputs are introduced. The signals the driver is reading (the feedback) are not muddied by the trailer. The TV deficiencies are at the fore. Prominent. Obvious.

Getting passed close by a big truck at a far higher speed? With a Hensley you don’t feel it at the steering wheel until his bow wave hits the rear of the truck. Then you’ll know how sloppy that pickup really is. Body getting pushed sideways from the rear (and your too-long receiver length adding leverage) with tires straining against the suspension while you’re sawing at that wheel to keep the pickup ONLY in its lane. The trailer is wondering what all the fuss is about.

Address the real problem.

My pickup is nearing a quarter-million. Now finishing first replacement set of tires and nowhere near 4/32s. 50/50 Town & Country. Pressures don’t change hitched or unhitched as truck doesn’t change that much with 1,200-lb TW (450-lbs ea approx to Steer & Drive) when I connect the 35’ travel trailer.

Get the baseline first: WDH correct.

Test the tire pressure rise after Cat Scale check (having started with dead cold readings at dawn). 1.5-hrs steady-state Highway on cruise control. No lane-changing, accel or braking while below the traffic flow. Glide to an easy, easy stop at rest area. Check values. 7-8% rise is fine. More needs a bare PERCENTAGE increase. Least amount.

Find lowest. (Equalization value)

Your vehicles ride on AIR.

Completely empty or fully-loaded, you want THE RANGE of the tested MINIMUMS necessary.

( Note to CR: “payload”, “trailer tow capacity”, etc are advertising. Advice. Legal requirements are door sticker Axle/Wheel & Tire Limits).

.

.

* This post was last edited 09/09/20 06:45am by BackOfThePack *   View edit history


2004 555 CTD QC LB NV-5600
1990 35’ Silver Streak

CapriRacer

Somewhere in the US

Senior Member

Joined: 01/27/2012

View Profile


Offline
Posted: 09/09/20 06:54am Link  |  Quote  |  Print  |  Notify Moderator

MFL wrote:

Jim, not to discredit the tire boys, but the manufacturer of the OP's tires says they are LT tires, which I suspect is true with a max psi of 51 and 2,535 LR. .....


Sorry, but here's another correction:

1) P type Standard Load tires will have a max pressure of either 35 psi, 2.5 bar (36 psi), 44 psi, or 51 psi. A P type XL (Extra Load) tire will have a max pressure of either 41 psi or 50 psi.

2) An LT tire will have a max pressure of 50 psi (Load Range C), 65 psi (Load Range D), 80 psi (LR E). etc. (with some exceptions)

3) It is common for tire manufacturers to put letters in the model name of the tire including LT, ST, HT, etc. This does NOT mean the tire is an Special Trailer, Light Truck, or Heavy Truck, etc. type tire. Those designation are in the SIZE - and in the case of ST and LT tires, they are explicit. (others, like P type, they are implicit.)

You may find some exceptions to the above as not everyone has a good understanding of how this works. For example, there are several tire manufacturers who put on the sidewall of their Standard Load P type tires: Max Load XXXX pounds @ max pressure 44 psi. This is sort of incorrect as the max load occurs at 35 psi, but 44 psi is the permissible max pressure with no increase in load.

Yes, I know it is confusing.


********************************************************************

CapriRacer

Visit my web site: www.BarrysTireTech.com

Grit dog

Black Diamond, WA

Senior Member

Joined: 05/06/2013

View Profile


Offline
Posted: 09/09/20 10:35am Link  |  Quote  |  Print  |  Notify Moderator

Or to sum up the last 6 pages for the guy who just wants safe tires for his truck pulling the camper, the tries that are on it are perfectly fine at the loads they'll see and will handle quite well when aired up appropriately.
And LR D or # tires would be even stiffer, aired up appropriately or a bit more and they'll last longer than the comparable P/XL tire.


2016 Ram 2500, MotorOps.ca EFIlive tuned, 5” turbo back, 6" lift on 37s
2017 Heartland Torque T29

MFL

Midwest

Senior Member

Joined: 11/28/2012

View Profile



Good Sam RV Club Member

Offline
Posted: 09/09/20 10:57am Link  |  Quote  |  Print  |  Notify Moderator

CapriRacer... no need to apologize, your opinion is worth just as much as mine.

I agree on the confusing. Hard for everyone, to keep up on the new ratings of various TV tires. The OPs tires are called light truck for 1/2 T trucks/heavy SUVs, but not designated LT in that size. I was wrong to suggest to Jim, that they are LTs, and he is knowledgeable enough to know that. He has real world experience, and stays current, concerning tires, making him, IMO, a top source of tire info, on this forum. Now add in towing large trailers, which you can only learn from experience, what works the best. Using your example, the 44 psi will LIKELY work best, even if max load may begin at a slightly less psi. Like I suggested much earlier, if you could borrow a TT with 1K+ TW, hooked up to a modern 1/2 ton, you could try it, come back, tell us what you learned.

Didn't mean to seem condescending earlier in the thread, but did not want the OP to take advice of towing that heavy, with low door sticker inflation. He was wanting to know if his tires were adequate, and the answer is yes, with proper inflation. More psi will make his towing experience better, especially in the rear. After 6 pages of opinions, I hope he sees this is by far the most popular opinion, of experienced towers, that posted in this thread.

Jerry





BenK

SF BayArea

Senior Member

Joined: 04/18/2002

View Profile



Posted: 09/09/20 11:33am Link  |  Quote  |  Print  |  Notify Moderator

Boils down to understanding...or not...of what a rating is...and in this topic...reference to tires.

Let out all the PSI from a tire with the vehicle weight on it

Rim will be down to pavement with the tire carcass between them

Air up and at some PSI point, the rim will lift the vehicle weight off the pavement

Continue airing, increasing the PSI and the rim will lift even higher, as now the tire ‘can’ carry more weight

Then up to the PSI as mentioned by one of our resident tire engineers (CapriRacer) and is the ‘rating’ for ‘that tire

Increasing the PSI will have the tire be able to carry more weight, but it will not be ‘rated’ for it (same metric for discussions of TV ratings and what they can carry/tow)

That increased PSI over max rated weight carry is more to keep the tires shape during its multitude of duty’s...carry weight, braking, accelerating, cornering, etc, etc, etc

Sure it ‘can’ carry more, but not within the specifications published (labels, brochures, specification sheets, etc) and be able to meet the criteria employed during design and certification testing.

That is where comments of : “into the safety margins” means. It will do it...but how long, how safely, etc. Big one is duty cycle and that is another area not understood by too many.

Gives me a headache trying to explain designed to specifications and ratings. What is baked into that design is lost to those who do not understand the process

This is a ditto for everything engineered or designed to a specification

One example that has worked on one of my old forums...with shooters/reloaded. They understood receiver/chamber pressure ratings. Sure you can increase the powder charge to increase the pressure and have the bullet fly faster/flatter/farther/etc...but they understood that it might work for a while or instantly fail...but the understood that it WOULD fail sooner or later...the working load and breaking load of a rope also worked for non shooters...

Aspirin anyone ?

BarneyS

S.E. Lower Michigan

Moderator

Joined: 10/16/2000

View Profile



Posted: 09/09/20 07:27pm Link  |  Quote  |  Print  |  Notify Moderator

BenK wrote:

Snip...

Aspirin anyone ?

Yes - PLEASE![emoticon]
Barney


2004 Sunnybrook Titan 30FKS TT
Hensley "Arrow" 1400# hitch (Sold)
Not towing now.
Former tow vehicles were 2016 Ram 2500 CTD, 2002 Ford F250, 7.3 PSD


Timeking

Florida USA

Full Member

Joined: 06/26/2010

View Profile



Good Sam RV Club Member

Offline
Posted: 07/24/21 10:20am Link  |  Quote  |  Print  |  Notify Moderator

I have the Nokian HT One tires (51 psi max) on my 2016 RAM 1500.

TT hooked up with WD.

With 50 psi in rear and 40 front, rims are both at 24 1/4 inch high (top of rim to ground).

With 44 in rear and 40 front, rear is at 24 and front at 24 1/2.

So ... it seems advice to max rears is valid.

Grit dog

Black Diamond, WA

Senior Member

Joined: 05/06/2013

View Profile


Offline
Posted: 07/25/21 12:12pm Link  |  Quote  |  Print  |  Notify Moderator

^Sort of. If that’s the right pressure for the load.
OTOH, I have tires on our current truck, that I couldn’t reasonably put enough weight on the truck to need to run them anywhere near max pressure.

Reply to Topic  |  Subscribe  |  Print Topic  |  Post New Topic  | 
Page of 6  
Prev

Open Roads Forum  >  Towing

 > Question about tires
Search:   Advanced Search

Search only in Towing


New posts No new posts
Closed, new posts Closed, no new posts
Moved, new posts Moved, no new posts

Adjust text size:




© 2022 CWI, Inc. © 2022 Good Sam Enterprises, LLC. All Rights Reserved.