Tire pressure confusion - Legacy Elite 2 POLL

[Hokieman]

7 minutes ago, CRM said:

FYI, your VIN is still showing. Written vertically on the right side.

Thanks, just edited it out. 

[CRM]

On 8/20/2022 at 11:16 AM, John E Davies said:

IF YOUR PLACARD IS DIFFERENT FROM THIS PLEASE POST A PICTURE.

Mine shows 65psi, but then again, it looks like my labels were made on a late Friday afternoon. Missing tire sizes and incorrect GVWR and GAWR ratings. Edit- And even "V.I.N" is spelled incorrectly. 😄

[Brian and Brandelyne]

On 8/22/2022 at 6:28 PM, John E Davies said:

Only by referring to the manufacturer’s load chart was he able to determine the ideal pressure for his new set of LT 10 ply tires. He decided on 67 psi for his 9000 pound AS.

Correct, and the best way to determine this is to WEIGH your trailer unloaded and fully loaded for travel. When I ran Goodyears on the Airstream I was happy to see they produce a comprehensive chart each year for their RV "Special Trailer" ST tires.

I recommend the CAT SCALES app for your phone. When you go to the scales, open the app, put in the number and drive on. Once your weight is taken, you will get a notice on the app and an email with your scale certificate. It will show total trailer weight, rear and front TV weight and combined weight. Compare these to what your tire chart states for your trailer and TV and adjust accordingly.  There is NO one-pressure-fits-all answer.  55 psi is probably a very good choice for the current tires given the "likely" loaded trailer weight.

GREAT CONVERSATION, this definitely needs to be understood by everyone who tows!

Brian

rv_inflation.pdf

 

Edited October 20, 2022 by Brian and Brandelyne
spelling

[Geronimo John]

On our 2018 OE2, I run 50 PSI on highway and 30 PSI on unpaved roads.

It would be useful to know if others are doing something simular.

BTW, having a Dewalt 20V air compressor on board makes my life SOOOOO easy now.  

GJ

[John E Davies]

9 hours ago, Geronimo John said:

On our 2018 OE2, I run 50 PSI on highway and 30 PSI on unpaved roads.

It would be useful to know if others are doing something simular.

BTW, having a Dewalt 20V air compressor on board makes my life SOOOOO easy now.  

GJ

I will air down to about 35 psi on the trailer if it is really nasty potholed rutted for a long distance. But folks need to be aware you have to air back up immediately when the speeds get back up to normal. Sometimes it may be hard to find a trailer sized pullout when you get back to a highway…. Keep that in mind too. 

John Davies

Spokane WA

[Hokieman]

On 10/20/2022 at 10:30 AM, Hokieman said:

I just submitted a Service Ticket requesting a newer decal with 55 psi tire pressure recommendation.   I also recommended all previous owners be sent a decal, and a tech services bulletin to explain why.   Others might wish to do the same, perhaps OTT will respond to our request.

I finally got a response to my ticket from 10/20/22 yesterday.  The request for a replacement decal was denied with a polite note explaining that the tire pressure on the trailer at time of production met the production tire specifications.   They recommend I consult OEM tire manufacturers specifications for the loaded trailer weight.   Which is exactly what many of us have already done, and the reason I have been running 50 psi since Delivery Day.   The ticket was closed. 

[Geronimo John]

Trailer's have been wearing out tires for ages.  They can run in an amazingly wide range of tire  pressures successfully.  However running above or below that "Sweet Range" and the tires will make you quite angry.  So bottom line we are talking about where in the Sweet Range we should run our OE2's.  I submit that all the recommendations above are less than optimal and should not blindly be used.   So before you get out your flame throwers, ponder the below first.  I believe that within the "Sweet Range":

A.  Tires run at a lower pressure likely have a better ride for Ollie, but they also require greater power to run down the highway.   

B.  Tires run at lower pressure when damaged get to flat quicker than ones at a higher pressure.  This results in less opportunity to get pulled over before you start trashing the highway with dismembered rubber tire components.

C.  Tires run at higher pressures are more prone to puncture from pot holes and road hazards.  Especially so when off road.

QUESTION:  So GJ, how do you run most efficiently, at a pressure to be the most flat resistant mode, while giving Ollie the best ride, and provide my family the best safety margin should you have a puncture?  

Answer:  You can't have it all at the same time.

QUESTION:  OK GJ, what tire pressure do you run your Ollie at?  

Answer:  Depends.   If I am on the interstate or good roads running at highways speeds I use 50 PSI.  When I go off road, I air down to 30 PSI for most conditions.  If I am transiting soft ground and need maximum sink resistance, then down to 20 PSI. 

QUESTION:  But GJ that's a PITA isn't it? 

Answer:  Nope.  I use a TPMS and an IR temperature reader to keep a watch on bearings (With hub caps removed as JD suggested), have a quality calibrated air gauge, and have a 20V Dewalt compressor.  Takes me less than 12 minutes to air up/down four Ollie tires between highway and off road mode.

Point is that each of us have different trailer weights that can vary depending on our loads at the time. We also travel different paths that our trailers must endure.  SO, is it  "OK" to say I air my trailer tires to XX PSI?  Sure if it is in the sweet spot.  It may be OK, but it sure is not optimal for all purposes as your trailer weight varies, as do your road surfaces and speed.

Hence, my recommended Ollie tire pressure is.... It depends.

GJ

[John E Davies]

That is primarily an illustration of why a Jeep owner “airs down” when going onto loose terrain. Wider footprint, more grip, less spinning and trail damage, at the expense of slightly lower ground clearance... It also shows why the tires’ rolling resistance goes up when you deflate your Ollie from 80 to 40 psi. It’s interesting to see that the footprint doubles in area between 40 and 15, but the change is a whole lot less dramatic above 40 psi.,.

 My sweet spot is 42, because I do minimal Interstate cruising, but lots of back highways and less that ideal road surfaces, AKA POTHOLES. Hit a 3 or 4 inch deep pothole at 50 mph with rock hard tires and you will think your trailer exploded. This shows a main arterial route here in Spokane, where we get lots of freeze thaw cycles.

It also shows why the center stripe paint gets worn off so fast, all those studded tires on cars avoiding the holes 

BTW one of the local weather reporters calls the arteries “artillery” routes. It’s a hoot.

John Davies

Spokane WA

[Geronimo John]

JD:

Great graphic.  I intuitively knew what was happening with air pressure and tire contact/drag forces, but had not seen it visually.

thanks for sharing.  It also makes a great justification for not going over 50 PSI on our OE2's unless it is way loaded.  For us in the 6,000 pound group, doing so would appear to be little drag reduction with increased down sides as discussed above.

Would be totally cool if OTT could run the OE2 over a glass plate at these pressures to see how close it mimics the Jeep visual.  My gut says it would be really close.

GJ

 

[Wayfinder]

Once again I would like to thank @Hokieman for putting me onto this thread and everyone who participated on this thread.  I had missed it when you guys are actively creating it. 

With my new Michelin Agilis Crossclimates going on the trailer next week, they will still be brand spanking new by the time I make it to the rally, let the inspection begin. 😉 I have doubts that I will be able to tell any difference from my original 2015 Michelin LTs, while driving.  It sounds like I will be just fine staying within 45 to 55 PSI, no matter how heavy I load the trailer and maintaining 7000 lbs, unless I load up with too much good Lagar.   🙂 

Many of us continue to learn from these forums.  Thank you all!  It's really appreciated by me.

 

[routlaw]

On 8/20/2022 at 9:16 AM, John E Davies said:

 

This has not yet happened, here is the one I made for the older tires (I run mine at 42 psi, with an approximate 6000 pound trailer weight.):

From the 2022 Owners Manual

This does not surprise. From the chart above one could even assume a tire pressure of 40 and perhaps even 35 might be adequate given the weight of a 6000 lb trailer. From various other online charts I've come across they tend to be approximately the same as above. Thanks