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205/75/15

JaycoQuest
Explorer
Explorer
I’m thinking about increasing the tire size from a 205/75/15 to 225/75/15 on a 2001 Jayco Quest.

Has anyone increased to that tire size?

Are there any benefits?

Any recommended ST tire ply or a ST radial tire?

Would there be a difference if I used a 205/75/15 and not a ST tire?

Another concern is about the increased height causing the steps to be higher and cause a problem.
16 REPLIES 16

time2roll
Nomad
Nomad
JIMNLIN wrote:
Looking at Costco they sell Greenball tires for TT’s they say their made in California.

I don't think we have any radial ST tires made in the USA. Better double check your source.
I think they are made at the Port of Long Beach. A big floating machine spits them right out.

JIMNLIN
Explorer
Explorer
op wrote:
This might sound off key but what happens to the weight of the trailer when you load it with the necessities? Do you compensate for the load range for that?

NO.
The trailer maker has already done that. You just meet or exceed the trailer axle ratings by say 10-20 percent. Now if your going to over load the trailer then a higher load range may be necessary if your wheels/axles are rated for the higher load and pressure ratings.

I’m looking for that buffer and that wider footprint for more contact on the road surface in heavy rains.

A wide foot print isn't the best idea on a trailer especially on wet pavement. If you notice trailer wheel widths run in the 5.5" on up to 6.5" for the biggest 15" and 16" tires.

A wide base tire on a multi axle trailer adds more side load stress to the tires internal belts/wheel bearings/axle U bolts/spring hangers/main frame rails as the tire side scrubs around a corner.
I wouldn't consider the 80 or 85 or 75 series tire as being a wide base tire.


Looking at Costco they sell Greenball tires for TT’s they say their made in California.

I don't think we have any radial ST tires made in the USA. Better double check your source.
"good judgment comes from experience, and a lot of that comes from bad judgment" ............ Will Rogers

'03 2500 QC Dodge/Cummins HO 3.73 6 speed manual Jacobs Westach
'97 Park Avanue 28' 5er 11200 two slides

JaycoQuest
Explorer
Explorer
hotqld wrote:
The Minus Clearances are a bit tighter. Brakes were lousy bigger tires need more braking power, Fixed up a voltage drop issue was 8 volts now 11 volts they work much better. Next rewire from brake controller to get better voltage at the brakes.


How did you do that fix?

All this information is priceless and thank you.

This might sound off key but what happens to the weight of the trailer when you load it with the necessities? Do you compensate for the load range for that? I’m looking for that buffer and that wider footprint for more contact on the road surface in heavy rains.

Load range. The tire is specially use for the trailer weight.
"C" range tires are 6 ply rated and inflated to 50 psi max
"D" range tires are 8 ply rated and inflated to 65 psi max
"E" range tires are 10 ply rated and inflated to 80 psi max

As goducks10 said In a GY Marathon the 225 is only 1-1/4" taller. That would only raise the trailer 5/8". A 205/75/15C needs 50psi for a max load of 1820lbs. The 225/75/15C also only needs 50 psi but gives you 2150lbs. That height is reasonable.

Looking at Costco they sell Greenball tires for TT’s they say their made in California.

GreenBall

Caught this off of http://www.linkedin.com/groups/Exactly-meaning-LRC-LRD-LRE-77975.S.155522701

With regards to Specialty Trailer tires (designated ST) it refers to the Load Range (Hence the "LR") of the tire. Typically most manufacturers go between C and F, depending on size.

It corresponds directly to the maximum inflation pressure for the tire, increasing in increments of 15 PSI. C=50, D= 65, E=80, F=95.
To get the maximum load capacity you will still have to refer to the manufacturer's data tables, since the load capacity will also vary with the size of tire (not just the LR).

For instance, while a ST205/75R15 LRC may have a maximum capacity of 1820 lbs, yet a ST215/75R14 LRC has a capacity of 1870 lbs - a difference of 50lbs both at 50psi, due to the differences in sizing and volume of air contained in the tires.

time2roll
Nomad
Nomad
Lynnmor wrote:
I replaced the 205's with Goodyear Wrangler LT's 215/75-15. Made in USA!
Good call ! 🙂
I almost did same. Drank the Maxxis cool-aid instead.

hotqld
Explorer
Explorer
I have increased Tire size on our Funfinder 244RBS.
Was 20575R14 to 215 /70/R14
The plus
Had two blow outs with the old tires at about 12,000 miles that had a load rating of 1400lbs the new tires have a load rating of 2250lbs.
Tire pressure can be increased from 50 to 65psi, we have set ours on 60psi.
Stability appears just as good. Hopefully a bigger footprint so will help towing in the sand.

The Minus
Clearances are a bit tighter.
Brakes were lousy bigger tires need more braking power, Fixed up a voltage drop issue was 8 volts now 11 volts they work much better.

Fitted shock absorbers at the same time.
Next job....rewire from brake controller to get better voltage at the brakes.
Plus install the Tuson Electric Sway Control.

JIMNLIN
Explorer
Explorer
op asks wrote:
I’m thinking about increasing the tire size from a 205/75/15 to 225/75/15 on a 2001 Jayco Quest.

Has anyone increased to that tire size?

Are there any benefits?

The ST205/75-15 tire takes a 5.50 wide wheel and can be a load range C at 1850 and 50 psi..... or a D at 2150 lbs capacity and 65 psi.

The ST225/75-15 tire takes a 6.00 wide wheel and can have a load range D or E at 65/80 psi respectively.

Your present wheels width and pressure rating dictate which size and load range they can use for best results.

Any recommended ST tire ply or a ST radial tire?

Would there be a difference if I used a 205/75/15 and not a ST tire?

Hmmm... a bit confusing terms but a ST comes in the old tech bias ply or a radial ply. Bias ply tires are ok on a lawn service trailer that spends its life running around town.
I would use a radial tire on a road trailer.

The 205/75-15 you mentioned IMO is a P tire and not a good idea on a trailer with 1800-2100 ?? lb minimum load requirements.

You need a ST radial on that trailer. A good upgrade would be moving on up to a LT depending on your trailers current axle ratings.
"good judgment comes from experience, and a lot of that comes from bad judgment" ............ Will Rogers

'03 2500 QC Dodge/Cummins HO 3.73 6 speed manual Jacobs Westach
'97 Park Avanue 28' 5er 11200 two slides

Lynnmor
Explorer
Explorer
I replaced the 205's with Goodyear Wrangler LT's 215/75-15. Made in USA!

artguys
Explorer
Explorer
If your'e only increasing size then your'e only increasing cross-section values which allows for more volume of air thereby increasing load capabilities. But not by that much...however if it was a drive tire and not a trailing tire other values would change as well.

hddecker
Explorer
Explorer
Increased Load Range has a bigger impact than increased tire size. Increase both size and LR if you can.

You probably wouldn't notice any effect on you stair height.

hawkeye-08
Explorer III
Explorer III
The OEM tires are the bare minimum usually to handle the trailer, I always look to have a buffer for load ratings and hopefully with proper inflation, the tires run cooler and last longer..

travelnutz
Explorer II
Explorer II
For reference:

"C" range tires are 6 ply rated and inflated to 50 psi max

"D" range tires are 8 ply rated and inflated to 65 psi max

"E" range tires are 10 ply rated and inflated to 80 psi max

These are the industry standards but of course there are some bending the accepted rules (mavericks) used to make their tires sound better than their competition. It's called "marketing" and miss-leading marketing claims do NOT make the tire any stronger but so many are sucked in!
A superb CC LB 4X4, GM HD Diesel, airbags, Rancho's, lots more
Lance Legend TC 11' 4", loaded including 3400 PP generator and my deluxe 2' X 7' rear porch
29 ft Carriage Carri-lite 5'er - a specially built gem
A like new '07 Sunline Solaris 26' TT

time2roll
Nomad
Nomad

travelnutz
Explorer II
Explorer II
I always do and have gone to a larger than the OEM tire on all our Vehicles, TT's, 5th wheels, boat trailers, etc when replacing the OEM's but only if there's room for a larger tire. Probably well over 2 dozen times so far over the last 40-50 years. The tread depth lasts much longer than OEM's and the tires are not stressed to their max rating. Usually only approx $10 per tire to go bigger and/or stronger and gain so much. It's been a win everytime. The manufacturer never seems to use a heavy/high enough capacity tire to suit me and it's all about cost! What's wrong with having a safety margin anyway as I'm a retired aoutmotive engineer and know better than to design to only 100% of the required minimums. 125%+ makes so much more sense! Just hitting a chuckhole etc with a tire already stressed to 100% can or may be the final tire killer and it's avoidable!

Don't get crazy though with extremes in tire sizes and create other problems like rubbing or hydroplanning during heavy rains. Which vehicle or RV you have can make a lot of difference also and also the climate/weather/temps should be considered on how much larger a tire or type is used.

Those are human lifes being carried in vehicles and even having a blown tire on an RV will ruin a fun vacation or weekend and why? So why not be a little safer and also save money in the long run?

Examples: The 245/75/16 "E" OEM Bridgestone etc tires with 3042 capacity on our trucks were replaced with 265 Michelins with 3415 capacity. The 225/75/15 "D" radials OEM's with 2540 capacity at 65 psi on the trailers were replaced with 225/75/15 "E" range radial tires having 2830 capacity at 80 psi.

Twice I've had to put a 1" spacer between the spring and the axle to gain needed room above the tire but that's no big deal and very cheap to do.

Using the right tool/item for the real task at hand always and then life usually goes so much smoother.
A superb CC LB 4X4, GM HD Diesel, airbags, Rancho's, lots more
Lance Legend TC 11' 4", loaded including 3400 PP generator and my deluxe 2' X 7' rear porch
29 ft Carriage Carri-lite 5'er - a specially built gem
A like new '07 Sunline Solaris 26' TT

goducks10
Explorer
Explorer
In a GY Marathon the 225 is only 1-1/4" taller. That would only raise the trailer 5/8". A 205/75/15C needs 50psi for a max load of 1820lbs. The 225/75/15C also only needs 50 psi but gives you 2150lbs. On Tirerack the 205 is $86.00. The 225 is $89.00. Seems like a good deal to me.

Only issue is your rim width. 205 needs 5-6.5". 225 needs 6-7". Of yours are 6" then you'd be good to go.