Upsizing/Upgrading Tires on 8286WS FW

[TopTiger]

Looking to get rid of stock tires installed on my Rockwood 8286WS. Unit currently has 15" C load rated tires provided by Forest River. C load rated tires barely enough for 4000lb axles. Not sure Forest River stock wheels can even handle D load rated tires safely. Rims would have to hold at least 60psi. Also, stock tires seem to be losing 5 to 10 psi every ten days or so. Only have about 2K miles on them. Worry about blow out surprises on the road with these cheap tires. Been down to Discount Tire and am looking at moving up to new 16" alloy wheels so I can move up to higher pressure E load rated tires. Checked clearances by temporarily installing two 16" wheels on one side with LT225/75R-16/E1 Cooper tires. Appeared there is enough clearances all around. Lost about one inch between the two tires. Top clearance lost about same. 115Q E load rated tire is overkill with 2679lb load rating but hope upgrade will make towing safer and less worrisome going down the road. Any opinions or experience out there on moving up to 16" wheels or doing something similar?

[cadman99]

I upgraded to Hercules tires, both on my truck and trailer to get a higher load rating.

You can get either 205/75/15 in "D" rating- 2150lbs
or 225/75/15 in "D" rating - 2540lbs or "E" rating - 2830lbs.

So far 10,000 on the truck and 3,000 on the trailer - They do not lose air when stored. I looked at larger rim sizes but was a bit worried about "tire to trailer" clearance even with a "225" tire. Finally opted for 205/15 with a "D" rating. These tires were very "round and true on the balancer".

Here's a link to Hercules - http://www.herculestire.com/tire-gal...lty/power-str/

[TheBennetts]

I posed the same inquiry to the dealer where I recently purchased my 2015 8289WS. He said they had no complaints about either the 15" aluminum wheels or C rated tires. He gave me the number for the tech support at FR who echoed the same thing. To paraphrase him, he said the aluminum wheels are rated to 65 psi and although some people upgrade to D or E rated tires, it is not necessary as FR makes sure the tires and wheels are well matched to the weight and specifications of the camper. He also said if I decided to upgrade to the E rated tire there is no concern with the PSI on the wheels. His caveat though is that FR will not warranty the new tires or any damage, should any occur. He said that warranty and liability will fall to the folks that sell and install the new tires.

Just passing on what the tech person said. I'll pass on the name and number of the tech rep if you want it.

Ken

[DaveSchwartz]

I agree that the stock LRC tire on the full-size 82xxWS leaves too little safety margin for the most critical piece of the GVWR chain. I'm a bit paranoid about tires and would rather the rubber not be the weakest link.

The place I get all my tires is right beside the dealer where my 8282WS should be arriving in less than two weeks. The second stop (after my driveway) after pickup will be to swap for a set of GY Marathon LRDs, balanced with a TST TPMS that I also have on order.

My previous TT was about ~5000 GVWR and had Nanco LRC tires. I had one of those fail on my second trip (about 300 miles on it). Put the spare on and ran those same four tires for 8 years and probably 15,000 miles (always at 50psi). Tread was getting a bit low and one was losing about 2 psi a week when the TT was written off by a deer strike. I consider myself very lucky - on the tires at least.

P.S. Even though LRD is rated at 65PSI max and LRE is rated 80PSI max, you would not be running these pressures. The required pressure is mostly a function of load and should technically be set according to maintain the proper deformation ('squash') of the tire to achieve the proper contact patch and ride. A tire needs some deformation but not too much but since its hard for a consumer to know how to measure that, manufacturers produce load/inflation charts. Goodyear has one on available for download but it should apply to pretty much all manufacturers. If you run those LRE tires at 80PSI on your 8286WS they are going to be rock hard, break all your dishes and shake all the screws loose.

IMHO you really only need to go up in load range if the actual maximum weight on the tire would require an inflation pressure over the maximum for the tire you have.

[TopTiger]

Thanks for input. Sales and tech reps said same to me, but experience taught me to upgrade any factory tires to at least a D load rating. Chances of blowout significantly reduced. Did this on last Dutchmen bumper pull after blowout incident and the next 5K road miles were pretty much worry free. Still always checked pressure before pulling out, but air loss slowed and towing stability improved.

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[TopTiger]

Tire to trailer clearance checked. With E rated lost about 1" clearance side to side. About same above. Seems like plenty and still safe. That's why I am inclined to plus size to 16"wheels and go to E load. Wonder if towing will be better and maybe mpg improved. 16" wheel with E load is what I also have on my F250 6.4l. Anyone get better mpg with plus size wheels? Don't know what if any effect Tire size has on mpg.

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[AquaMan]

Originally Posted by TopTiger

Tire to trailer clearance checked. With E rated lost about 1" clearance side to side. About same above. Seems like plenty and still safe. That's why I am inclined to plus size to 16"wheels and go to E load. Wonder if towing will be better and maybe mpg improved. 16" wheel with E load is what I also have on my F250 6.4l. Anyone get better mpg with plus size wheels? Don't know what if any effect Tire size has on mpg.

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On a previous TT, I upgraded from a 14" to a 15" wheel/tire combo. Went from C to E rated tire and the handling/mpg both improved. Rolled much better on the highway and gained a solid 1-1.5 mpg avg.

[DaveSchwartz]

The reason you have LRE on your F250 (SRW?) is that your RAWR is probably in the 6,000 range. That means you could easily dump enough stuff in the bed that would exceed the ~2500 lbs that LRD at max pressure could carry. The same is not true of your 8286.

[DaveSchwartz]

Originally Posted by AquaMan

On a previous TT, I upgraded from a 14" to a 15" wheel/tire combo. Went from C to E rated tire and the handling/mpg both improved. Rolled much better on the highway and gained a solid 1-1.5 mpg avg.

Not saying you can't use LRE for the safety margin, just that if you inflate to max pressure even though you are far from max load your trailer will not enjoy it.

[Cajun Po-Boy]

Toptiger...definetly will see improved mpg, especially if you maintain the cold max psi posted on tire sidewall.
Less rolling resistance and heat build up if you maintain max psi rather than a lower psi...camper will understand! ,)

Also, during those moments when you have to maneuver the camper in an awkward side way motion, tires will be much more willing to do what you want when at max psi.

[TopTiger]

Figure the LRE will make trailer more bouncy off the Interstates, but thinking trade off benefit in reliability, safety and mpg will be worth it. Granted, I may be wrong and bouncy creates different set of problems. I am assuming Forest River construction can handle a little more bouncy. We may have to do better job at stowing our dishes!

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[OldCoot]

Originally Posted by TopTiger

Figure the LRE will make trailer more bouncy off the Interstates, but thinking trade off benefit in reliability, safety and mpg will be worth it. Granted, I may be wrong and bouncy creates different set of problems. I am assuming Forest River construction can handle a little more bouncy. We may have to do better job at stowing our dishes!

You'll never be able to tell the difference in the ride. The load margin and less rolling resistance will be more than worth it. If you're worried about how the trailer rides and really want to improve it, put shocks on the trailer.

[TopTiger]

Thanks OldCoot!
I think the up-sizing to 16" LRE is more of an investment in "peace of mind" than anything else! Had enough road rescue experiences in this life. Probably spending way more on wheels than necessary, but at my age I just want to move on down the road without white knuckles and anxiety attacks! LOL!

[DaveSchwartz]

Everybody's going to have their own internal value calculation for peace of mind. I am taking the advice of the wise old heads on this forum (and elsewhere) to swap out the no-name Chinese LRC tires for GY Marathon LRD.

Besides the quality factor, what figures into the calculation is the following number crunching...

The stock specs of my new rig are a 7944lb unloaded vehicle weight, cargo cap of 1406 and pin weight of 1324 (I know my CC will be reduced by the weight of my options). Assuming the worst case that I'm a bad load-master and all the cargo weight ends up on the trailer tires, that's 8026 on the tires when the LRC max is 8600. That's 93.3% of tire capacity or only 143 under max per tire.

Too close for my comfort (also not super happy that its right at the axle ratings but not much I can do about that).

Going to LRD, the max is 10160 and I'm now 79% of tire capacity or 533lb under each tire's max.

That (and a TPMS) does it for me.

[TopTiger]

Right on Dave!
Even though I am moving up to 16" LRE's I am also installing TPMS. High load margin is peace of mind!

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[cadman99]

Don't think so - adding tires to an 8000# barn door going 60 MPH ain't gonna improve gas mileage you can measure.