110 psi tire pressure??

[ken_burke]

All . . . . help. What tire pressure should I use on my ST235/85R16 tires by West Lake (forest river). My 5th wheel is heavy, i.e. 3000 pounds on each wheel and tongue. (15,000 pounds total). My tires are G rated and limit is 4080 pounds (actual weight is 3000). Max presser on is 110 psi. Do I have to run that high of pressure??
The problem is how to I get that pressure with a portable tire inflator? Also most tire inflators are DC hooked up with the trucks 12 volt. that won't work.

thanks . . . . ken

[jadatis]

ken burke wrote:
All . . . . help. What tire pressure should I use on my ST235/85R16 tires by West Lake (forest river). My 5th wheel is heavy, i.e. 3000 pounds on each wheel and tongue. (15,000 pounds total). My tires are G rated and limit is 4080 pounds (actual weight is 3000). Max presser on is 110 psi. Do I have to run that high of pressure??
The problem is how to I get that pressure with a portable tire inflator? Also most tire inflators are DC hooked up with the trucks 12 volt. that won't work.

thanks . . . . ken

Have put it in my made calculator and filled in that 3000 tonge weight and Loadindex 129 as given , gave 90psi as answer.
BUT this is not what I would advice.
First your maximum load is calculated for 65m/h so I lowered the loadindex by 5 steps to give the tire a deflection that it would need for 99m/h , saver and less fuel consumption and still acceptable gripp.
Second your tonge weight is as you give 20% of total weight and as far as I learned in America for middle -axle trailers by law it must be between 10% and 15% , but correct me if I am wrong.
If I fill in 10% tongue weight so 1500 lbs and that lower loadindex of 124/3530lbs maxload i come to an adviced pressure of 118 psi , wich tiremaker does not allow anymore ( earlier days 10 pasi above that 110 psi allowed) so you have to keep them to 110 psi.

This is higher advice then the TT maker would give , but sertainly save for the tires and still not to much bumping.

To yust keep your tires on pressure , even a bicycle pump can do.
Ofcource not to fill from zero to 110 psi , but the average 10psi fill upp needs about 20times pumping a tire.
Those for race-bycicles with manometer can fill to your pressure.

[ken_burke]

Searching_Ut wrote:
I too have G rated tires on a similar weight 5er, and have found 110 PSI seems about right, even towing on snow and ice. After about 7000 road miles now tire wear looks even and minimal. I use a Viair 450p DC inflator that I clamp right to the 5er battery most of the time as it's easy to get at in my rig. The little DC compressor works as good or better than the craftsman 4hp 125 psi compressor I have in the garage which doesn't go high enough pressure wise to fill the trailer tires most of the time due to the way it cycles.

All . . . thank you all for your quick and complete response to my question. I just ordered the Viair 400P-RV thru Amazon. Cost was $251. As above it is a DC pump that connects to the battery. This should solve my problem with G rated tires. thanks

[NHIrish]

Another 150 psi compressor option, fairly light at 20 lbs. You will need a power inverter to run it on the road...

Porter-Cable CMB15 0.8 HP 1.5 Gallon Oil-Free Fully Shrouded Hand Carry Compressor

[Old-Biscuit]

ken burke wrote:

Old-Biscuit wrote:
West Lake Tires......a Chinese Brand, doesn't have a Tire Load Chart

With those West Lakes 4080# at 110psi I would run at least 100#

I have Goodyear G614s..run them at 110psi and keep them inflated using my Viair 400P 12V DC air compressor

With the high air pressure required you need to invest in a GOOD portable 150psi compressor.

Thanks. I am looking into a portable a/c, but they are really heavy. What power do you use for your DC inflator? Do you plug into the truck/s DC system, or go directly to the truck battery?

I use the alligator clips on the Viair compressor and clamp onto one of the trucks batteries or onto one of the 5th wheels batteries.

Although I checked 5vr tires every travel day (early AM prior to travel and usually every week) I rarely need to add very much air pressure.

Trucks rear tires.....had to pump them up every travel day as I would decrease air pressure down to 45# when not towing (during week or 2 weeks we would be parked) and then pump them back up to 80# for towing.

Viair compressor is 10 yrs old and I use it here at S&B House more then my 120V AC Compressor as it is very handy/light weight and just needs a good battery to clamp onto.

[Searching_Ut]

I too have G rated tires on a similar weight 5er, and have found 110 PSI seems about right, even towing on snow and ice. After about 7000 road miles now tire wear looks even and minimal. I use a Viair 450p DC inflator that I clamp right to the 5er battery most of the time as it's easy to get at in my rig. The little DC compressor works as good or better than the craftsman 4hp 125 psi compressor I have in the garage which doesn't go high enough pressure wise to fill the trailer tires most of the time due to the way it cycles.

[Cameo_Phil]

Make sure you use steel tire valve stems instead of the rubber snap in type. Rubber tire stems are only rated for 80psi.

[Us_out_West]

ken burke wrote:
All . . . . help. What tire pressure should I use on my ST235/85R16 tires by West Lake (forest river). My 5th wheel is heavy, i.e. 3000 pounds on each wheel and tongue. (15,000 pounds total). My tires are G rated and limit is 4080 pounds (actual weight is 3000). Max presser on is 110 psi. Do I have to run that high of pressure??
The problem is how to I get that pressure with a portable tire inflator? Also most tire inflators are DC hooked up with the trucks 12 volt. that won't work.

thanks . . . . ken

How long have you had your 5th wheel?

[azdryheat]

You don't need DC power if you're airing up when plugged in to shore power while camping. I have a 3 gallon compressor on board. Come to think of it, I rarely have to add air to the LT truck tires.

[ken_burke]

Old-Biscuit wrote:
West Lake Tires......a Chinese Brand, doesn't have a Tire Load Chart

With those West Lakes 4080# at 110psi I would run at least 100#

I have Goodyear G614s..run them at 110psi and keep them inflated using my Viair 400P 12V DC air compressor

With the high air pressure required you need to invest in a GOOD portable 150psi compressor.

Thanks. I am looking into a portable a/c, but they are really heavy. What power do you use for your DC inflator? Do you plug into the truck/s DC system, or go directly to the truck battery?

[RinconVTR]

Run at max cold PSI as your trailer sticker likely confirms.

Run ALL ST tires at max cold psi - ALWAYS.

[time2roll]

I would run 5 to 10 psi above the chart not to exceed sidewall max.
Running max is fine too. Check pressure before you roll and before the sun is on the tires.

A quality 12v compressor will go 110 - 150 psi. If it has a cigar plug it is weak. If it has a 30+ amp fuse and clamps direct on the battery you should be fine. My MV-50 works fine for me but it might take a bit to get to 110 psi. Viair is also a great brand.

Or for the big boys there is Oasis that draws up to 200 amps and makes 200 psi.
http://www.oasismfg.com/dc-air-compressors.html

[JIMNLIN]

Its recommended that tires on trailer be used at max sidewall pressure ...however if that 3000 lbs per tire is a actual scaled number then I would do as these experts say.

rvsafety.com

Tire Load and Inflation Ratings

* Note: Towable – Travel Trailer/ 5th Wheel owners Due to the severe use conditions experienced by tires when axles are very close together – tire industry experts recommend maximum (sidewall) inflation pressure for towable tires unless this causes a sever over-inflation situation (20psi+), often referred to as the ‘basketball effect’. If this is your situation allow a 10 – 15psi safety margin above the minimum required inflation pressure.*


And some good pointers on trailer tire pressures from another source;

fifthwheelstreet.com

Step #5..
Selecting the Correct Tire Pressure for Your Trailer
We at Fifth Wheel St. no longer recommend adjusting trailer tire inflation pressure below the maximum load PSI rating molded on the sidewall (and only if the wheel/rim is appropriately rated) regardless of the measured scaled weight of individual tire or axle positions for all multi-axle trailers.

However, we do strongly recommend weighing individual trailer tire positions to ensure none of the axles or tire positions are overloaded. Reports have shown that trailers do not have equal weight across all tire positions. Some RV load configurations may reveal as much as 20% difference between the front and rear axle. This especially true for Toy Haulers. It is possible that mismanaged trailer load distribution will cause one end of an axle or a tire to be overloaded. It has been stated, but never confirmed by any RV Weighmaster, that there are many RVs traveling on the road with at least one tire or axle side overloaded. The only way to ensure tires and or axles are not overloaded is to weigh each tire position on your trailer. Unfortunately, attempting to obtain accurate individual tire position weight is practically impossible at all truck scales. View our list of recommend RV Weighmasters here.

- See more at: http://fifthwheelst.com/step5.html#sthash.FIAc3k0Z.dpuf
.........................................................

I don't carry a compressor ....can't help you there.

[jus2shy]

If you need more pressure, just look into a Viair 400P or 450 12V compressor. They're rated to around 120 or 140 psi. It also has a pretty good flow rate for a 12v compressor, so you're not sticking around forever pumping air. It takes 20 minutes or so to air up my truck from 15 psi to 60 psi on all 4 positions on my truck after driving on the beach. That's with a large 275/70r18 tire. Your tires are much smaller volume wise.

[Old-Biscuit]

West Lake Tires......a Chinese Brand, doesn't have a Tire Load Chart

With those West Lakes 4080# at 110psi I would run at least 100#

I have Goodyear G614s..run them at 110psi and keep them inflated using my Viair 400P 12V DC air compressor

With the high air pressure required you need to invest in a GOOD portable 150psi compressor.