17.5 tires

[Forddude11]

Right now I am running 235/85 Goodyear G614's on my 16,000# GVW fifth wheel. My pin is just under 3,000# at 2984#. I am looking to change the tires as they are carrying a 2009 date code on them... I have the ability to jump to 17.5 rims and tires.. I can't imagine there are any cons to make this move other than initial cost , but will ask anyway....Should I save the money and just do the direct replacement , or make the jump? Are the G114's hard to find on the road if needed ?..THX in advance..

[gitane59]

bucky wrote:
OK men, let's make this easy for you. Go lower the tire pressures our your car, or your truck, or even your riding mower. Now go drive it. Some of you will say oh that's not the camper. OK, go get the freaking camper. Now lower it's tire pressures also. Now go drive that. Report back. Even the damn Gov knows that fuel mileage increases with proper inflation, why do you want to belabor the point? OH that's right. Nobody on this forum knows anything but YOU.

Go back to bed and get up on the other side. You're grumpy Bucky;)

[bucky]

OK men, let's make this easy for you. Go lower the tire pressures our your car, or your truck, or even your riding mower. Now go drive it. Some of you will say oh that's not the camper. OK, go get the freaking camper. Now lower it's tire pressures also. Now go drive that. Report back. Even the damn Gov knows that fuel mileage increases with proper inflation, why do you want to belabor the point? OH that's right. Nobody on this forum knows anything but YOU.

[JIMNLIN]

mpierce wrote:

bucky wrote:
Dropping the pressures is hard on your fuel mileage, the trick is finding the best compromise.

Not really. Point is, if using 16" tires, and need 80# to hold the load,then you go to 17.5, you still probably only need about 80# in them to hold the load. NOT the 125# that they are rated for.

Putting 80# in the 17.5 will yield same mpg as 80# in 16", and be a softer ride than running them at 125#. And, at 80#, the 17.5 is a stronger, tougher tire carcass.

Not really.
I've found those heavier carcass G tires run hotter with much more parasitic drag (rolling resistance) using only 80 psi in them.
I tried that silly trick of over tiring my small 5 trailer fleet of GN /enclosed trailers with higher G load range tires and run 80 psi in them even after my truck tire dealer suggested not to. I found out the hard way he was right.

Tireman9
rvtiresafety.com


The question of load capacity and Load Range gets asked a lot, so it seems to be a bit of a stumbling block for a number of RV owners. Here is an example:
"I need to replace the ST235/75R15 tires on my trailer. Currently have load range C tires which is sufficient for the maximum trailer weight when inflated to 50psi but allows almost no safety margin. I want to change to either load range D or E tires. My rims are only rated for 65 psi so if I went to the load range E tires I would only be able to inflate them to 65 psi. My question is this. Is there any advantage to a load range E tire used at 65 psi vs a load range D tire at 65 psi?"

Now just because he is asking about a 15" trailer application and considering a change from LR-C to LR-D it does not mean the general answer does not apply to others, even if they are considering a change from LR-G to LR-H on a Goodyear 295/75R22.5 Class-A tire.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

The answer to the question is;
He will gain a safety margin if he increases his inflation to 65psi with LR-D but if he stays at 65psi there is nothing further gained by going to LR-E as there is no difference in the capacity at 65psi.
The same thing would apply to the 22.5 example. When we look at the Goodyear tables we see that at 110psi both the LR-G and the LR-H are rated for 6,175# single or in dual application at 100psi they both are rated as 5,675#.

Special note: It is important that you look at the table on the web site of the manufacturer of your tires as not all companies give the exact same capacity number at every inflation level, even for the same size.

[Cummins12V98]

mpierce wrote:

bucky wrote:
Dropping the pressures is hard on your fuel mileage, the trick is finding the best compromise.

Not really. Point is, if using 16" tires, and need 80# to hold the load,then you go to 17.5, you still probably only need about 80# in them to hold the load. NOT the 125# that they are rated for.

Putting 80# in the 17.5 will yield same mpg as 80# in 16", and be a softer ride than running them at 125#. And, at 80#, the 17.5 is a stronger, tougher tire carcass.

Bingo! We have a winner!

[mpierce]

bucky wrote:
Dropping the pressures is hard on your fuel mileage, the trick is finding the best compromise.

Not really. Point is, if using 16" tires, and need 80# to hold the load,then you go to 17.5, you still probably only need about 80# in them to hold the load. NOT the 125# that they are rated for.

Putting 80# in the 17.5 will yield same mpg as 80# in 16", and be a softer ride than running them at 125#. And, at 80#, the 17.5 is a stronger, tougher tire carcass.

[bucky]

Dropping the pressures is hard on your fuel mileage, the trick is finding the best compromise.

[gitane59]

I'll second the vote for the Sumitomo 17.5 inch tire.

16 inch trailer tires = Piece of Rubber interrupting your trip.
17.5 inch trailer tires = Peace of Mind enjoying your trip.

if you tow frequently many miles the average cost of your peace of mind drops with each mile towed.

As to the poster that talked to someone who said the 17.5 tire would be to hard on a fifthwheel the answer is to inflate the tire only enough to cover the actual weight on the tires plus the 20% safety factor.
Although the Sumi's max PSI is 125psi giving you 4800lbs cap I inflate mine to 105psi giving my 4065lbs cap which is more than enough for my trailer and softens the ride at the same time.
Just make sure you refer to the manufacturers inflation chart

[Jerry_B]

My friends very recent experience with G614 tires: He just got the RV out of the shop from a previous G614 explosion. Put a new set of G614s on and just yesterday, one of the new month old G614s exploded. Repair parts on order. I have had two G614s explode on my Mobile Suites. I am now trying to find what size 17.5 LRH tires I should use on my Mobile Suites. All of the failed tires on my RV and the friends RV was the left front tire location. Obviously too heavy.

[fsujeeper]

i got mine from wheels from rickson wheel. they are a pleasure to deal with.

[Cummins12V98]

Seattle Lion wrote:
Is there a good deal out there for the 17.5 wheels and tires? I have 7,000 lb axles.

Scott at trailertiresandwheels.com

[Seattle_Lion]

Is there a good deal out there for the 17.5 wheels and tires? I have 7,000 lb axles.

[Glenn_West]

On our Mobile Suites our Goodyears thru caps. Replaced with same tires and 0 problems. Believe it was a bad batch. On the subject of finding tires it is a******shoot. I have never found good rv tires in stock. Lots of Chinese bombs. I needed a replacement tire yesterday. E rating. Ended up with a Chinese bomb!!! Michelin XPS ribs two day order only.

[kakampers]

Forddude11 wrote:
I spoke to a tire guy that I know , he told me that the G114 at 17.5 are a heck of a lot stiffer and will beat up the camper...?? He has never seen a set put on one , does that sound right ?? He also said that I will NOT find one on the road....?

What BS...they are optional on quite a few of the higher end units now....DRV, Excel even on Landmark! Haven't needed to find one on the road because they give you NO problems! Unlike our G614's which threw the tread at 2 years!

[Hunter11]

We have a new unit on order and I upgraded to the Goodyear 17.5 G114 H rated tires and know others running them. Your tire guy seems to be out of touch.