Tow Vehicle Tire Pressure

[cjunken]

So to make a long story short we had a flat on our first outing with our TT this past weekend. It appears that it was a puncture to one of the tow vehicles tires, but during the ordeal our roadside assistance gentlemen made a statement that concerned me. He was commented how my tires were really just light duty tires and likely not adequately inflated to be pulling what I have. So now the question becomes who should I turn to for help assessing what tires and pressure would be ideal? I've been reading conflicting information on the web and want to make sure I'm not putting myself in danger. I will consult my local tire shop for advise, but does anyone here have general guidelines they use such as inflating to max psi listed on the tire sidewall etc.
Thx

[Gdetrailer]

dave54 wrote:
The downside to max sidewall PSI is when you unhitch. Running around locally with little to no weight and tires inflated to max is the vehicle will ride like a army tank.
Doesn't really hurt the vehicle, but the occupants will be bounced around like peas in a kettle drum.

Not really true.

Back when I had a "heavy half" I ALWAYS ran FULL SIDEWALL PRESSURE.

That was with "P" Passenger tires and the sidewall pressure rating was 44 PSI.

With "P" or Passenger tires, you will BARELY NOTICE A DIFFERENCE IN RIDE running full 44 PSI or running say 32 PSI when empty.

Now with my 3/4 ton with sidewall pressure rating of 80 PSI there is a slightly noticeable difference in ride when running full sidewall pressure and empty..

Even then not all that bad and when camping a long way from home for a week or so a LITTLE BIT OF RIDE DISCOMFORT IS NOT ANY REASON TO BOTHER REMOVING THE AIR WHILE DISCONNECTED.

The only reason I do drop my pressure a few lbs on my 3/4 ton when home is to PREVENT TEARING THE CENTER TREAD OFF WHEN EMPTY.

So, the way I see it, if you are running Passenger tires (as pretty much all 1/2 tons do), run the full sidewall pressure all the times, UNLESS, you notice the centers of the tires wearing out before the outside tread..

That IS what I do with all of my cars and my former heavy half and it works very well, gives you best gas mileage also.

Now for LT tires on trucks, yeah, reducing the pressure a couple of pounds can soften the ride SLIGHTLY when empty but not all that much.. Tire wear tends to be more important ($250 per tire for my last replacements) and lowering the pressure a couple of lbs can help to get more even tire wear..

For trailers, I always run max sidewall pressure, most trailers will be loaded pretty close to the max tire capacity and this is no place to skimp on air (tire capacity goes DOWN or is DERATED with lower pressure). Chances are you WILL replace the trailer tires BEFORE the tread wears out..

[profdant139]

I inflate to the max -- I recently asked DW if she was ok with the rough ride, or should I air down just a little. Her response: "Heck, it's a truck. It should ride like one. Plus, the extra vibration feels great on my back -- it's like a free massage!"

We know we are on a really good forest road when small objects come flying out of the dashboard cubbyholes.

[TurnThePage]

Yes, P rated tires need to be de-rated 10%. But even after that, mine are still rated considerably higher than my trucks GAWR, and even higher yet when compared to the GVWR.

I've driven half tons daily for the last 20 years with both P rated and LT rated tires. No doubt LT rated tires offer more stability when towing and are more forgiving (performance wise) if not aired up correctly. But P rated tires perform plenty well IF they are aired to MAX pressure and not overloaded.

[shemphill]

P-metric or Euro-metric tires are designed for passenger cars. If you have them on your suv, pickup or van tow vehicle, they should be de-rated by 10%:
https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=70

They are passenger tires and are designed for less load with respect to their rating. In an emergency situation such as an evasive maneuver there is much more than just the vertical force on them, plus the center of gravity is higher. LT tires are much more robust. I would change out my passenger car tires for LT tires prior to towing a heavy load (like a TT near the limit of my vehicle). With an LT tire you will have a much greater safety factor, and don't actually need to pump the tires up to max sidewall rated pressure where you will lose traction sooner in an evasive maneuver due to less contact area with the ground combined with less compliance with ground irregularities.

[afidel]

dave54 wrote:
The downside to max sidewall PSI is when you unhitch. Running around locally with little to no weight and tires inflated to max is the vehicle will ride like a army tank.
Doesn't really hurt the vehicle, but the occupants will be bounced around like peas in a kettle drum.

Haven't had a problem with my TV at 50PSI, it's a little harsher riding but still way, way less harsh than the 2500 I rented before buying my truck.

[dave54]

The downside to max sidewall PSI is when you unhitch. Running around locally with little to no weight and tires inflated to max is the vehicle will ride like a army tank.
Doesn't really hurt the vehicle, but the occupants will be bounced around like peas in a kettle drum.

[Community Alumni]

I run the max sidewall pretty much all the time on the trailer and the truck. The truck has 51 PSI tires and the trailer has 80 PSI.

[Community Alumni]

shemphill wrote:
I've noticed the tires on new TT's are barely enough to carry the GVW. Potholes, those new vertical handicapped curbs, debris, etc. can easily throw the dynamic load well above the tire ratings. I've been hearing that LT tires are a good upgrade. Anybody have any experience with them?

I've run LTs on trailers over the years. Earlier this year I swapped the 15" load D STs that came with my current trailer for 16" load E LTs. I've never experienced any problems running LTs. I'm not going to get into the whole debate about which is better, but I consider them to be an upgrade and you'll be fine to run them.

[Terryallan]

shemphill wrote:
I've noticed the tires on new TT's are barely enough to carry the GVW. Potholes, those new vertical handicapped curbs, debris, etc. can easily throw the dynamic load well above the tire ratings. I've been hearing that LT tires are a good upgrade. Anybody have any experience with them?

Biggest reason TT tires are not rated more. Is that they will never carry the GVWR of the TT. the tongue weight of the TT will be on the TV. So the weight on the trailer tire are lightened by that much. could be 400lb, and could be 1200lb.

As for LT tires. Many use them. Just remember. trailer tires are designed to run straight at speed, and also to scuff sideways while backing, and turning sharp.

[Terryallan]

bguy wrote:

coolbreeze01 wrote:
Max psi allows the tire to carry its max rated load. Low psi causes heat buildup in tires and heat kills tires.

Your tire is rated to carry somewhere around 2600lb @44PSI cold. Less
PSI = less capacity.

"Most tires with a max PSI of 44, are rated to only 2175lb. 2600lb and over take 50 PSI.

To the OP. Max PSI when towing ALWAYS. You may not need the weight capacity, but you do need the stability.

[shemphill]

I've noticed the tires on new TT's are barely enough to carry the GVW. Potholes, those new vertical handicapped curbs, debris, etc. can easily throw the dynamic load well above the tire ratings. I've been hearing that LT tires are a good upgrade. Anybody have any experience with them?

[TurnThePage]

Ditto. There is no danger in maxing out the pressure. Go for 44 PSI. With P rated tires, every bit helps. It also adds significant stability when towing.

[coolbreeze01]

cjunken wrote:
So truly the only safe bet would be to load up and get it all weighed to really verify how everything sorts out. I have a pic of my tag and looks like front axle rating is 3100 and rear axle is 3300. Cold pressure is listed at 35 but sidewall max says 44. So I'm thinking that I'd like to bump that up to about 42 at least. It didn't ride horribly on the interstate but I'm hoping that a 20% increase in pressure may stiffen up the ride a bit.

I'd put in 44lbs.

[cjunken]

So truly the only safe bet would be to load up and get it all weighed to really verify how everything sorts out. I have a pic of my tag and looks like front axle rating is 3100 and rear axle is 3300. Cold pressure is listed at 35 but sidewall max says 44. So I'm thinking that I'd like to bump that up to about 42 at least. It didn't ride horribly on the interstate but I'm hoping that a 20% increase in pressure may stiffen up the ride a bit.