Goodyear G614 air pressure

[Hamnet]

Not sure if this has been asked.
Original set of tires had 80 pounds max pressure. The Good years has 110 max cold pressure. The tire shop put 90 pounds in them. My rims are rated for 110#.
Since I ran original tires at 80, should I continue with 80 or put max cold air pressure in the goodyear. Our 5th wheel max weight is 14995. When I am loaded we usually weigh around 14500 pounds.
Thanks

[Cummins12V98]

fj12ryder wrote:
But that really is one heck of difference between 80 psi and the max of 125 psi., as opposed to a max of 110 psi, and running pressure of 95 psi. The first would be a difference of 36 percent, versus 13 percent. Major difference. And it may have as much to do with the aspect ratio as anything else, with the shorter sidewall. I believe the 17.5" is a 215/75 versus the 16" 235/85.

Personally I would be uncomfortable running less than 90 psi on my "G" rated Sailun tires. But that's just me.

What does the load/inflation chart say? If it's listed there would be no concern.

[fj12ryder]

But that really is one heck of difference between 80 psi and the max of 125 psi., as opposed to a max of 110 psi, and running pressure of 95 psi. The first would be a difference of 36 percent, versus 13 percent. Major difference. And it may have as much to do with the aspect ratio as anything else, with the shorter sidewall. I believe the 17.5" is a 215/75 versus the 16" 235/85.

Personally I would be uncomfortable running less than 90 psi on my "G" rated Sailun tires. But that's just me.

[JIMNLIN]

And gosh, I was so worried. Anything could have happened over these last five years of running reduced air pressure. But, unsurprisingly, it didn't.

Yeah.... lots of folks have used the old Carlisle's/Tow max and other ST poly tire maypops and had good luck with them. Most RV folks never wear a tire out and don't put many miles on a tire.

Here is another RVer that found a downside of going way over his actual load per tire needs....
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Posted: 04/27/17 08:01am Link | Quote | Print | Notify Moderator
When it came time for me to replace our tires, I researched many different ways to go. I wound up purchasing 17.5" J rated medium duty truck tires and wheels. When all done and said, it was $5.00 per wheel and tire combo more than just replaceing the 16" tires. This tire and wheel combo is good for 6005 pounds each. Using the inflation chart to get the pressure for the load, I inflated to 80 psi which was good for 4500 pounds per tire. With the first tow with these tires to Kansas City, I have made this trip to the speedway several times before, I was down almost 2 mpg both ways. The tires were 20*-25* hotter than the truck, which I have never experienced before. I inflated them to the side wall pressure, 125 psi for max load, before our trip to Florida. Now the tires run 5*-10* cooler than the truck and my fuel mileage is back where it used to be. I have always run max pressure up until I installed these tires, with what I have experienced, I will continue to run what the side wall indicates.

[cummins2014]

Cummins12V98 wrote:
I will stick to what GY Tech Support says to do.

"So, if your OE tires provided 3520# of load capacity inflated to 80 PSI, your target is 3520# for the GY G614s. That’s going to be right at 100 PSI."

May be true but I did not see what tire size the OP was running???

IMO, and being G614's, I would run max air pressure of 110 psi. If they were Sailuns I would run according to weight ,and inflation chart.

[Cummins12V98]

I will stick to what GY Tech Support says to do.

"So, if your OE tires provided 3520# of load capacity inflated to 80 PSI, your target is 3520# for the GY G614s. That’s going to be right at 100 PSI."

May be true but I did not see what tire size the OP was running???

[fj12ryder]

According to Tireman9, lowering the air pressure for me is pretty much a non issue then. Since the load on my tires, which are rated to 3480, is only 2000-2500 lbs. I'm golden. 24 percent of max load carrying capacity of 3480 lbs. is 870 lbs., that would be over 2500 lbs. Perfect. Running the lower pressures isn't a problem. And gosh, I was so worried. Anything could have happened over these last five years of running reduced air pressure. But, unsurprisingly, it didn't.

Dunno if the OP is a double or triple axle.

[JIMNLIN]

Goodyear Tire and Rubber .... weighing RVs
Special Considerations

Unless trying to resolve poor ride quality problems with an RV trailer, it is recommended that trailer tires be inflated to the pressure indicated on the sidewall of the tire. Trailer tires experience significant lateral (side-to-side) loads due to vehicle sway from uneven roads or passing vehicles. Using the inflation pressure engraved on the sidewall will provide optimum load carrying capacity and minimize heat build-up.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

and from Tireman9 (actual tire engineer) rvtiresafet.net tire blog tells us why max pressures are needed to help hold the tire together while side scrubbing around corners... (snipped for length)

**When not driving in a straight line there are special side loads on multi-axle trailers because the tires are fighting each other because they are not "pointed" to the center of the radius of the turn. These loads cause interior structural tearing. Sometimes 24% higher loads than those seen in tires on non-trailer application. Initially tearing is at the microscopic level but with time and repeated cycles these forces grow which can lead to small cracks at the belt edges.
You can lower these forces by either decreasing the load 24% on the tire (probably not something you want to do or may not be able to do) or you can increase the inflation to stiffen the structure and decrease the slip-angle. In this case you could increase the tire inflation from the minimum inflation needed for the static load to the inflation associated with the max tire load as molded on the tire sidewall.

[Hamnet]

Thank you all so much. One more quick question. What is the range of tire temperature if I use a infra red beam type. I read where some people have used that. I had one so I will carry and check when I stop.

[JW_of_Opechee_S]

I inflate my 614's at 100 cold and have had no problems for 2 years. They run at about 115-117 during summer hauling. I have EZZ Tire monitors for peace of mind.

[fj12ryder]

That is probably 90 percent CYA by the USTMA and the vehicle manufacturers. I read part of it but my eyes glazed over when I read the part about ST tires should never be replaced by any other type of tire. Looked pretty much like mostly lawyer driven boilerplate.

[CALandLIN]

Hamnet wrote:
Not sure if this has been asked.
Original set of tires had 80 pounds max pressure. The Good years has 110 max cold pressure. The tire shop put 90 pounds in them. My rims are rated for 110#.
Since I ran original tires at 80, should I continue with 80 or put max cold air pressure in the goodyear. Our 5th wheel max weight is 14995. When I am loaded we usually weigh around 14500 pounds.
Thanks

Tire industry standards are very specific about inflation pressures for “plus sized” replacement tires. This is what is required. Replacement tires must provide a load capacity equal to the load capacity the Original Equipment tires provided. That load capacity is determined by the vehicle manufacturer’s recommended inflation pressures for the OE tires. That information is found on the trailer’s certification label, tire placard or in the trailer’s owner’s manual.

So, if your OE tires provided 3520# of load capacity inflated to 80 PSI, your target is 3520# for the GY G614s. That’s going to be right at 100 PSI.

The USTMA says to NEVER use less tire inflation pressure than what has been recommended by the VEHICLE manufacturer. In this situation the new inflation pressure would be 100 PSI which equals the vehicle manufacturer’s recommendations. A well trained installer would have told you that.

Chapter #4 of the reference in the “click here” below supports that statement.

Click Here!

[Cummins12V98]

I did the same and ran 85psi. GY Tech says use inflation chart and add 5psi when up sizing load range. I NEEDED 80 with the "E"s and used 85 on the "G"'s for several thousand miles with perfect tread wear.

[fj12ryder]

I have the G-rated Sailun which are rated for 110 psi max, just like your Goodyears. Our toyhauler weighs 15,000 lbs., with 12,000 lbs. on the axles. I run our Sailuns at 90-95 psi.

Full pressure could give you a pretty rough ride. I would experiment to find the best ride, but I would start around 95 psi., and go up or down 5 psi at a time to find the best ride.