Tire Pressure

[Yukon]

Having a hell of a time figuring what preasure to run on Mich LTX M/S 2, LT225/75R16 Tires the Oliver came with . 80 psi Max. got that . Dry weight of Oliver being 4600lbs and gear 400lb including 20% water. I figure around 5000 total. any guesses?

[topgun2]

Yukon -

 

There have been several lengthy discussions of this topic here on the Forum.  Generally speaking it seems that the consensus is that "normal" on road tire air pressure should be between 50 and 65 psi depending on weight (heavier loads require greater air pressure).  If you need more information - try the "Search" function or this for starters:

 

http://olivertraveltrailers.com/topic/how-to-tire-pressure-placard/

 

Bill

[AndrewK]

Yukon,

 

The attached from Michelin should address your question.

 

Andrew

 

[attachment file=Michelin RV_Tires_Brochure.pdf]

 

Here is a link as well:

 

https://www.michelintruck.com/assets/pdf/Truck_Tire_Data_Book_Sept2011.pdf

Michelin-RV_Tires_Brochure4.pdf

[BackofBeyond]

For whatever reason, I can't get that pdf to open.

 

I reduced the air pressure on my tires to 60 PSI this last trip. Didn't notice much difference in towing, if any. I believe the Oliver has a softer ride, less road jarring at 60.  With the weight of my ollie (loaded and 1/2 water) approx. 6100lbs - it is well within the tire load ratings. I am also running the TireMinder TM55-B Wireless Tire Pressure Monitoring System. It is kinda cool - actually. My wife says I'm gonna have wreck if I don't stop checking it out......

 

RB

[KountryKamper]

Our trailer is 5500 lbs loaded and I run 57 PSI in the tires. Last year I ran 60 PSI but lowered it a little this year. I have a Dill TPMS and can not tell that the tires are running any hotter so I think that 57 will be my sweat spot for now. They felt really good on our trip last week.

[DavidS]

For whatever reason, I can’t get that pdf to open.

I think the problem is that the pdf is present only as an attachment.

 

@AndrewK, and others, when uploading a pdf file (or docx or xlsx file) you first need to click the Select File button, identify the file, and upload it. If you do just that, then the file will not be accessible to forum users.

 

After uploading the file another step is needed. You need to click on the Insert Into Content button, to the right of the Select File button. This puts your attachment into the body of your message, and, more importantly, makes it available for other Forum users to download.

[AndrewK]

Yukon,

 

Here is a link that should help you.

 

Andrew

 

https://www.michelintruck.com/assets/pdf/Truck_Tire_Data_Book_Sept2011.pdf

[AndrewK]

Thanks David!,

 

I followed your direction in Edit mode and it appeared to work.

 

[attachment file=Michelin RV_Tires_Brochure.pdf] showed in the body but when I submitted it didn't change anything.

 

Andrew

[SeaDawg]

Works for me now, Andrew. ?

[Geronimo John]

@Yukon:

 

If you use the attachment, and have a 5500 pound trailer weight reduced by the 10% that the tongue is carrying, then per that attachment you only need to carry 1237 pounds per tire.  That is off the chart, but is about 30 PSI.  Not Recommended by the vast majority of the owners.

 

What is recommended is that you get a Tire Pressure Monitoring System.   Set the pressure with COLD tires that have been in the shade.  The majority of us seem to be using a number in the mid to a bit higher 50's.  Like KountryKamper I have used 60 PSI in the past and will be lowering it to 56 or 57 PSI this season.  Having a TPM System has  lots of advantages, but I encourage you to Search the topic as there are only about 200 posts with lots of answers and opinions that certainly make for a good read.  But on the subject of having one,I have not heard one Ollie owner that has one that would run without it.  We pretty much all think it is an essential safety item.

 

You will also read in that search why you want to be well above the Michelin minimum settings.  As well as when you will want to lower the pressure off of the 50's due to road conditions.

[Raspy]

In previous discussions about tire pressure recommendations, it seemed the pressures listed in the charts were the minimum allowable pressure, not the recommended pressures.  That Michelin chart just seems to be the recommended pressures and I could not find where it said "minimum".

 

For instance, it shows 35 PSI as recommended for 1500 lbs on a single for the 225/75r16 E.  This would be 6,000 PSI total.  Fine for most Oliver LE2s.  But to me, that is way too low and is what I use off road to smooth out the ride in the desert at low speeds.  I'm sure it would run hot on the highway.

 

I have run most miles starting out at 60 PSI cold.  This isn't rock hard, but runs cool.   At 50 PSI I can feel the tires are warmer under the same conditions.  Still OK, but generating more heat.  That means a little more rolling resistance too.

 

With sustained high speeds in the summer out west, the tires run hot.  I don't like the idea of making them even hotter from lower pressure.  Starting out at 80 PSI and then going higher from driving on hot pavement at speed, seems like it would be harder on the trailer suspension and on the tires.

 

I don't have a TPMS for the trailer, but if I picked up a nail, 60 PSI would give me more time to spot it at the next gas stop, than 40 PSI would.

[Overland]

@yukon:

 

Not Recommended by the vast majority of the owners.

 

Most owners must consider Oliver a better authority on Michelin tires than Michelin. Really, the only reason people don’t run Michelin’s recommended pressure is that they have a hard time reconciling that with what Oliver put in. I’ve yet to see anyone give an authoritatively backed reason to not use Michelin’s recommendations.

 

I use 45 and the only thing I’ve noticed is that the brakes lock less often and things  stopped breaking.

[Raspy]

Geronimo John wrote:

@yukon

:

 

Not Recommended by the vast majority of the owners.

Most owners must consider Oliver a better authority on Michelin tires than Michelin. Really, the only reason people don’t run Michelin’s recommended pressure is that they have a hard time reconciling that with what Oliver put in. I’ve yet to see anyone give an authoritative alternative to Michelin’s recommendations.

 

I use 45 and the only thing I’ve noticed is that the brakes lock less often and things stopped breaking.

 

From the Michelin chart, it seems Michelin recommends 30 -35 PSI.

 

I consider that to be far too low and my reasoning is actual tire temperature measurements at different pressures, and the fact that a leak would make matters even worse in a shorter amount of time than running 60 PSI would.  Off road is a different story, but I'm referring to highway pressures.

 

Just curious, why are you running 45 PSI when the Michelin chart shows 30-35 PSI?

[Overland]

Their chart recommends 40 for me. I run 45 to give some buffer if I have a slow leak.  Also, I believe those numbers are maximums for each pressure so I don’t think you’d want to be on the edge, just like you wouldn’t want the tire on the edge of its maximum rated pressure.

 

I check my tires at every stop and they’re only ever slightly warm to the touch, always a good bit cooler than my truck tires, which I’d also characterize as warm. I also have temp sensors as part of my TPMS and as I’ve said before, sunlight has a far greater affect on their temp than pressure or speed.

 

You tell me, why do you think Michelin doesn’t know the proper pressures for their own tires?

[Raspy]

I consider the chart to list the absolute minimum acceptable pressure.  Even you are not using the Michelin charted pressure, and you are doing it for a perfectly logical reason, as am I, and many others.  So maybe you agree that Michelin doesn't always know best for every situation.

 

40 PSI on the Michelin chart would be for a total trailer weight of around 7,200 lbs.  You must be loaded pretty heavy if that is the number you used as the "recommended" number.  1,650 X 4 = 6600 + 10% tongue weight = 7260.  Mine only weighs 5,700. ready to go.

 

Fortunately, we are all running LT tires where we can vary the pressure for good reasons and not risk a blowout, as seems to be the case with ST trailer tires.   I've been advocating LT tires on trailers for years.

[KountryKamper]

Also consider you don't know the weight sitting on each tire. It could be very different between the 2 sides but could also be different between front and rear axle. All 4 tires are not going to be carrying the exact same weight even though I would think it close. The road side has the batteries sitting on top of them, the curb has the fridge and kitchen. Casitas were famous for blowing out curb side tires because of that side always being heavier on most models. Unless you weigh each tire individually there is no way to really know so you need to add some PSI to the minimum as a safety factor.

[Raspy]

Tom,

 

The equalizer suspension system makes the two tires on each side carry the same weight, or extremely close to it.  Right to left can be different and I don't recall what the difference was when I had mine weighed.  We weighed each tire and the tongue.  I have the values, but not in front of me.  The point is:  a few pounds difference is not enough to worry about if you are safely within the pressure per weight recommendations on the chart.  Why push it as close as possible with the minimum pressure?  I could not find the exact wording, but on similar charts I've seen, the pressures were the "minimum" required, not the max.

 

From actual measurements, tires run hotter at lower pressures.  I can easily read the difference between 60 and 50, for instance.  35 would make me nervous.  And no, I'm not claiming to know more than Michelin about tires, as was implied in an earlier post, as some false reason to vary from the chart.  It would probably be helpful in this discussion to determine for sure if Michelin means max pressure, recommended for all situations, or minimum allowable, in their charts.   I don't see any reason to run the minimum pressure unless I'm in the desert on a rough road at slow speeds.

[KountryKamper]

I was not able to weigh each side separately on any of the scales I have been on. It would be interesting to know just for reference what the difference was if you can find those numbers.

 

Surely the numbers on the chart are minimum numbers.

[Raspy]

I was not able to weigh each side separately on any of the scales I have been on. It would be interesting to know just for reference what the difference was if you can find those numbers.

 

Surely the numbers on the chart are minimum numbers.

 

 

I'll dig out the record tomorrow and post it.

[Raspy]

Tom,

 

Here are the weights for our 2015  LE2 measured under each wheel individually and under the tongue.  Five separate measurements with a certified scale, by Frederick at Bullards Beach, Oregon, last year.

 

I am surprised that the rear axle is carrying more weight since it's an equalizer suspension system.  I'm puzzled that the right rear is 325 lbs heavier than the right front.   Also interesting is the galley side is heavier than the battery side.  We were set up and camping on a level surface with some gear not in the trailer  (approx. 200 lbs) and the tanks about 1/2 full.   We have the (4) flooded cell Trojan T-105 bats, and two 30 lb propane tanks, about 1/2 full.  Six gallon water heater also full.  No solar on the roof.

 

Left Front                 1,155                    Total left side        2,385

 

Right Front              1,160                   Total right side     2,645

 

Left Rear                  1,230                   Difference right to left       260 heavier on the galley side

 

Right Rear               1,485                   Tongue weight with all gear aboard approx 10% average.

 

Tongue                        570

 

Total                         5,600

[RnA]

One of the big tell-tales will be the wear pattern folks are experiencing after running a significant number miles with a certain psi and trailer weight.  Too high pressure and the middle of the tread will show more wear.  Too low pressure and the outsides of the tread will wear faster.  Anyone out there have some info to share? - Randy

[Overland]

The wear on mine, after about 18,000 miles, is even across the tire. About a third of that mileage was done with Oliver pressures (over 70), a third at 50, then the last third at 45. There was no point during that time that I noticed uneven wear. I do have some wear that I suspect was caused by locking brakes, as that’s been an issue for us. It looks like the sort of wear you’d see on a tire that’s been abused by doing burnouts. Obviously that’s not the problem but I figure locking the brakes would produce similar damage. Could be from scrub but I suspect it’s the braking. And it seems like that wear isn’t getting worse after I first noticed, so perhaps it happened all in the first stint with the highest pressures, when the brake locking was the worst.

 

We just did another 3 week trip at 45 psi and no issues to report. Trailer was stable and tires stayed cool to the touch. We did a good bit of gravel road on this one - Chaco, Valley of the Gods, Moab, etc., and some bad paved roads as well. We bounced her around a good bit and happy to report zero damage. Ran across another poor couple on the east road to Chaco who’d completely destroyed a tire on their car. The rangers told me that road eats a few tires a week, but we cruised through with no problem. I’m not big on lowering tire pressures for offroad except for sand, so we just kept them as they were.

 

Raspy got me thinking about running a lower pressure, so I’m going to experiment with 40 psi on the short trip down to the rally, just to see. I’m not willing to go to 35 unless I read some clarification from Michelin about their chart. The way I read it, 3000 lbs is the maximum weight allowed at 35 psi and I’m at 2750+, which is too close for me.  But as I mentioned, we’ve had issues with locking brakes and each time I’ve lowered the tire pressure it’s helped, so why not at least try 40.

[Raspy]

Having a hell of a time figuring what preasure to run on Mich LTX M/S 2, LT225/75R16 Tires the Oliver came with . 80 psi Max. got that . Dry weight of Oliver being 4600lbs and gear 400lb including 20% water. I figure around 5000 total. any guesses?

 

 

Vector just lost two wheels from his LE2.  At least one of them came off when he hit a pot hole. Some of the speculation is that the tires may have had so much pressure that they were unable to absorb the impact, and sheared off the wheels studs.  The nuts may have been overtightened too, contributing to the failure.  No absolute conclusions have been reached yet.

 

80 PSI, whether it contributed to his failure or not, is too much pressure, in my opinion.  60 is much better and 50 may be better yet.  The tire chart shows a minimum required of about 35-40.

 

I ran 60 for a lot of miles and the tires ran cool.  I lowered it to 45 and found it was still OK, but the tires were warmer.  Now, I've settled in at  55.  The tires still run cool, but they have some flex if needed to take the shock out of pot holes.

 

Still searching for the ideal pressure based on actual use.  I'm thinking 50 will probably be it.

 

On slow desert unpaved roads, I like 35.  This minimizes the chaos in the trailer and can't heat up at low speeds.

 

I have a feeling, after Vector's incident, there will be a clarification, from Oliver, on the policy they recommend.  No more 80 PSI factory pressure.

[KountryKamper]

We also ran 60 PSI for the first year, about 11,000 miles with no issues. I am lowering it now on each trip and watching the Temps on the TPMS. Last trip I went to 57 with no problems. This trip to the rally I am going to 55 psi. We are leaving on a 6000 mile trip after the rally and will probably stay at 55 for that trip and experiment going to 50 on shorter trips when we get home. I don't think I will be going any lower then 50 psi.

 

I do pump them up to 70-75 psi if the trailer is sitting more then a few weeks without moving between trips.

[donthompson]

Question: I run 55 psi in my tires. I have a TPMS system that monitors pressure and temperature. On my drive to Hohenwald and back, the two tires closest to the tow vehicle consistently ran 15 to 20 degrees higher temperatures versus the two tires towards the rear of the camper. The temps were never too high, just different. I assume there is a logical explanation for this. Any opinions?