Tire rotation

[Rumline]

I've been thinking about this since the last tire pressure thread (http://olivertraveltrailers.com/topic/tire-pressure/).  True that according to the Michelin load tables (http://www.michelintruck.com/reference-materials/manuals-bulletins-and-warranties/load-and-inflation-tables/#/) 45 psi would give enough capacity for 7000 lbs. And I agree that using maximum carried weight in conjunction with a load table is the best way to go, otherwise you're just pulling numbers out of...a hat.

 

With that being said, I looked at the Tire and Loading Information placard on both of my current cars.  It specifies what PSI should be in the tires.  Then I looked up those figures (tire size and PSI) on appropriate load tables.  The combined load capacity was higher than the vehicles' GVWR by 22 and 28%.  I'm not sure if this is due to running P-metric tires or what, but should a similar padding be used with LT tires on a trailer as well?  Doing so would bring us back to 60 PSI.

[John E Davies]

We can all have opinions, but in the end Michelin’s is the one that counts.  

If you monitor your trailer tires using TPMS and have a 40 psi warning set, fine, run 45 psi in these tires, but you eliminate that reserve air that gives you time and miles down the road to react to a slow leak like a nail.

 

For someone without trailer TPMS, running 45 psi is foolish and risky. Once the tire starts to look flat it has been running in heat distress and it is too late to prevent internal damage which may not be visible.

 

We can talk this endlessly, but I still don't understand why Oliver will not:

 

1: provide TPMS as a factory option

 

2: Provide written guidance on a satisfactory and safe pressure range.

 

Their continued silence on this issue is troublesome. I have requested it by PM, maybe a few others here can do so too.

 

BTW I believe that a good trailer TPMS is one of the very best safety accessories you can have. It is affordable and will provide great peace of mind on lonely backroads when you are far from assistance. It will potentially save you money in the long run by preventing most types of tire failures, and it can warn of brake or bearing issues (if the sensors also monitor temperature).

 

John Davies

 

Spokane WA

[Overland]

With that being said, I looked at the Tire and Loading Information placard on both of my current cars. It specifies what PSI should be in the tires. Then I looked up those figures (tire size and PSI) on appropriate load tables. The combined load capacity was higher than the vehicles’ GVWR by 22 and 28%. I’m not sure if this is due to running P-metric tires or what, but should a similar padding be used with LT tires on a trailer as well? Doing so would bring us back to 60 PSI.

 

I'd guess I'd be careful comparing it to a car, not that it's not an interesting exercise or that there isn't anything to be learned there.  But on my truck, for example, the two axle ratings combined are higher than the GVWR, and I imagine the tire pressures would be determined per axle.  Plus car companies know that people tend to overload their vehicles - I know I've been guilty of that - where it's unlikely that anyone would get their Ollie over 7500 lbs.  Though again, I saw one of the Original Elite II's in service this week and Jason said that it was over 10k!

[Overland]

Overland wrote:

We can all have opinions, but in the end Michelin’s is the one that counts.

If you monitor your trailer tires using TPMS and have a 40 psi warning set, fine, run 45 psi in these tires, but you eliminate that reserve air that gives you time and miles down the road to react to a slow leak like a nail. For someone without trailer TPMS, running 45 psi is foolish and risky.

We'll have to disagree on that.  People have been setting their tires at the recommended pressures for forever and I've never heard of anyone saying that you need to add an extra safety margin, TPMS or not.  I think what would be foolish would be to intentionally decrease the everyday traction of your tires in order to add a safety margin for rare punctures.  Just check your tires regularly.

[Raspy]

 

We can talk this endlessly, but I still don’t understand why Oliver will not: 1: provide TPMS as a factory option 2: Provide written guidance on a satisfactory and safe pressure range. Their continued silence on this issue is troublesome. I have requested it by PM, maybe a few others here can do so too.  

 

In some ways, Oliver seems to be overloaded with all the accumulating details of designing, building and following up with endless questions.  They have made some mistakes and are slow to deal with them.  Examples such as wiring and water tank issues reveal this.

 

Tires are a consumable item on trailers.  Tire warrantees are handled by the manufacturer.  Brands and sizes change over time.  The same model trailer can weigh 5000 lbs to over 7000 lbs and can be towed once a year in cold weather or constantly  towed in 100 degree weather.  Traction on different surfaces can be significantly affected by pressure.  Some might want the lowest towing drag and others might want the best possible traction, while others might want the smoothest ride.   Tire pressure is never a definite number, so manufacturers give "maximum" and "recommended" values.

 

When you say you want Oliver to give "written guidance" it implies that they should be held responsible for wildly varying circumstances.  They do, as I understand it, recommend 60 PSI, which is a good all around starting point that will work well in most situations.  If a tire leaks and a problems occurs, it's not Oliver's fault, as the pressure at that point would be outside their recommendations and they cannot warrant against road hazards.  There have been so many trailer tire (ST) failures that many now opt to run them at full rated pressure, just as a way to keep them from blowing out from heat.  This is not the case with light truck (LT) tires that are MUCH more tolerant of varying pressures and can be tuned to the situation.

 

It would be nice if they offered  a TPMS system as an option, I suppose, but then they would have to have the interface with the tow vehicle, show people how to use it and guarantee it, etc.  Remember, they just went through a flap about solar controllers and defaulted to the one that was easy to use, but less efficient, in order to, probably, reduce their hassle factor.  They are also not known for their wiring prowess.

 

Better to let them build an excellent frame and body structure, as they know how to do very well, concentrate on the internal systems they must have and leave the minor options to owners.  For instance, I don't really feel the need for  TPMS on mine.  I check the tire temps and appearance at every point of interest stop or fuel stop and if one blows out I will instantly be aware of it.

[STEVEnBETTY]

Well stated Raspy, I don't feel the need for a tpms system either, with over 5 million miles driving class 8 combination vehicles, I've had a lot of experience with tires, though I'm not a tire guy.

 

Several years ago FedEx added tire monitoring systems to their trailers because the drivers wouldn't or couldn't ( take your pick) check their tires on a regular basis, the system automatically adds air as needed to the tire, while you would think this is a great idea in reality, not so much, what happens is tires don't get checked on a regular basis and if you pick up debris in a tire you're not aware of it, end result tire failure for loss of pressure and the heat involved in that.

 

Every time I stop I check my tires and wheel hubs, I run my tires at 65 psi and I can tell just by "thumping' them if their low, I also touch the tire and hub to make sure their not overheating, if one is hotter than the rest, there's a problem. If you run good quality light truck tires they very rarely fail.

 

Tpms systems are a great addition to your trailer, but there is no substitute for regular maintenance and periodic checks of running gear.