Forum Discussion

04FWPioneer's avatar
04FWPioneer
Explorer
Dec 13, 2013

Karrier ST205/75R14 Radial Trailer Tire - Load Range D

We own an 04 Fleetwood Pioneer model 18T that we just purchase last summer from a family who had driven it cross country from Washington state. They were the second owners and it appears that the TT was purchased in Washington state by the first family.

She is currently riding on four Goodyear Marathon tires that are starting to show signs of cracking on the side walls. One of them has a slow leak. IOW it's time for new tires.

The specs are as follows:
04 Pioneer 18T - Curb weight dry is 4000. GVWR is 6000 lbs.
Tires - ST205/75R14 Load range C (1760) or payload of 7040 lbs.
Rim - Outside dia: 15 3/8", Bolt 4.5", Center 3.25"

**I can't say for sure but these may be the original tires that came with the TT as there were no records in the receipts for a tire purchase and the previous owners (VERY OCD) didn't mention it. Plus the spare was almost glued to the spare tire cover.**

BEFORE reading numerous post on the forums about tires I knew that I wanted to upgrade, if at all possible, to a load range of "D". I understand that this will give me a higher maximum payload of 8160 lbs. on the tires that my TT chassis is not designed for. The purpose of upgrading was to go from a 6 ply tire to an 8 ply giving more strength where I need it. Just in case I should ever overload the TT. The speed rating is the same so no advantage is gained there.

AFTER reading for hours I am now MORE confused than when I started. So let me outline what I think I have gathered to be applicable.

1. There isn't much room between each set of tires on each side or between the top of the tires and the TT SO I don't think going up a size is possible. I will stay with the current size.

2. From what I can gather biggest difference between LT and ST is the side ply, load rating and speed ratings.
There are few 14" LT tires out there and all that I have found have lower load ratings than I have now. Although they have higher speed ratings. But I have no desire to go faster that 65 while towing 6K anyway.

3. There aren't to many 14" tires with a load rating of "D" either. But there are some and the Karrier above is one that I have found but have read nothing about thus far.
4. After reading I think I want to stay as close to factory as I can with the exception of the extra load rating which I see as a win - win for just a few bucks more.

SO has anyone heard anything about the Karrier line of ST tires?

Thank you in advance.

L
  • 04FWPioneer's avatar
    04FWPioneer
    Explorer
    Dec 28, 2013
    So from the replies I have 3 votes for Kuhmo, 2 for Maxxis and 1 for Karrier.
    But then another problem was identified and that is the rims are also psi rated and I have no idea what the PSI rating is for mine.

    SO I tried to look them up and found that mine have absolutely no name on them what so ever. On Etrailer.com there are some white spoke rims that look like mine and they are rated to 65 PSI. But I can't be sure.

    L
  • jadatis's avatar
    jadatis
    Explorer
    Dec 14, 2013
    The important difference between ST and LT is that an ST is calculated in its maximum load for a lower speed so more deflection allowed wich gives more load to carry at same pressure.
    I once calculated it for almost the same sises and maxloadpressure for ST and LT and the ST had 15% more maximum load.

    But its always better to give the ST the same deflection as an LT would have. And then even for tandem-axle use the maximum load for dual load ( so 4 tires on one ( virtual) axle).
    Then even add 10% to the load on the tire for things like , pressure loss in time, unequall loading over the tires , misreadings of pressure and weight scales, etc.

    Then the story gets different for your tires.
    Calculate for GAWR wich is 6000x0.9= 5400 and add 10% for reserve= 5940 lbs ( 0,1 is for tonge weight minimum allowed in America).
    Practice is that Trailers are always loaded to their maximum.
    But weighing and then preferably per wheel(pair) makes it shure.

    Old tires then 7040/1.15= 6122 lbs maximum load together of the 4 tires when they would be LT for single load. Then substact 7.5% for making it dual maximum load as is done in Europe ( America sometimes even 9% substraction) gives 6122*0,925= 5662 lbs 4 tires together dual load LT.

    Then you need about 5940/5662=1.05x50psi=52 psi, so higher then maxloadpressure wich is 50 psi but allowed up to 10 psi by TRA.

    If you now take the new tires with 8160 lbs maximum load for the 4.
    Then 8160/1,15*0,925= 6528 lbs maxload dual LT for the 4.
    Same sum 5940/6528= 0,91 * 65 psi= 59 psi to give it a save deflection of the tires, asuming D load also are ST.

    With my caravan trailer tire pressure calculator you can calculate it more accurate but these will be the advice pressures.
    With these pressures , asuming the load is realy to the max, still acceptable comfort and gripp.
  • MitchF150's avatar
    MitchF150
    Explorer III
    Dec 14, 2013
    I went with a higher load range when I bought new tires for my 2003 Prowler Lynx a couple of years ago. The OEM tires were Marathons (made in Canada) and the size was ST185/80R13 LR "B" (35 max PSI).

    I never had any problems with those tires for all the time I used them (about 8 years).

    I replaced them with Karrier Load Star tires, the same size, but LR "D" (65 max PSI).

    I run them at around 55 psi and very happy with them. 2 seasons with them and no issues.

    So, I like 'em... :)

    Mitch
  • WoodGlue's avatar
    WoodGlue
    Explorer
    Dec 14, 2013
    gmw photos wrote:
    Skip ! ....you almost disappointed me....it took 59 minutes for you to show up ! :B

    ....the data connection to Topeka must be slow today ! I hope you're healing well. Have a great holiday season.

    Hahahahaha!

    WoodGlue
  • JIMNLIN's avatar
    JIMNLIN
    Explorer III
    Dec 14, 2013
    If the Marathons were OEM they could be made in the USA back then. They were moved to Canada for a couple of years before being shipped to china.
    A 4000 lb dry weight = 1000 lbs per tire requirement.
    A 6000 GVWR = 1500 lbs per tire requirement.
    Actual weight on the tires is 6000 lbs less 600-800 lbs for the hitch carried by the tow vehicle. Higher rated tires won't help with a overloaded trailer.

    The Kumho 857 have a good reputation across the trailer world including RVs.

    The Maxxis U-168 commercial grade LT tire in several 14" sizes are also popular where they are easily available.
  • gmw_photos's avatar
    gmw_photos
    Explorer
    Dec 13, 2013
    Skip ! ....you almost disappointed me....it took 59 minutes for you to show up ! :B

    ....the data connection to Topeka must be slow today ! I hope you're healing well. Have a great holiday season.
  • skipnchar's avatar
    skipnchar
    Explorer
    Dec 13, 2013
    There are dozens of different names (none of them SOUNDING Chinese) that are made in China. I'd recommend avoiding ALL of them unless you plan on only local short trips. If you plan on doing any cross country I'd go with Maxis tires and a load range D is over Kill. I've got over 80,000 trouble free towing miles on my 8,000 lg. trailer using load range C Maxis tires.
  • gmw_photos's avatar
    gmw_photos
    Explorer
    Dec 13, 2013
    Yep, I'll jump in early here with another strong vote for Kumho 857 load range D. Very happy with the set I am running. Tire rack has them and you can compare the specs of the various sizes there.

    I would say it's just a matter of minutes now before the "M" crowd comes barging in here .... :) ;)
  • jrichard's avatar
    jrichard
    Explorer
    Dec 13, 2013
    Haven't heard of Karrier, but I've been happy with Kuhmo 857 14" range D...

    And I'd definitely move up to D for a few dollars more. But, to get a meaningful advantage out of D, you have to increase your tire pressure to 65lbs (from 50 for range C). So, you might need new rims.

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