Replacement Tires - DOWNSIZE?

[woody9]

Well, i'm sure the title will draw some in.. but let me give a bit of background..
Had a LONG trip planned for this past summer. The spring RV show had a unit DW & I fell in love with.. and we ordered one..
BUT.....
I'd already bought a set of NEW tires for the OLD trailer for the trip.
It had ST205/75R15 - C's on it.
I ordered ST 205/75R15 -D's for it.. (not a mile on 'em yet).

I'd figured i could put those on the NEW trailer after this trip.. and then noticed a flat on the new trailer yesterday and found a nail in one!
THAT'S when i realized the NEW trailer has ST225/75R15 -C's on it..

so.. if i DOWNSIZE to the NEW increased load range tires.. I wouldn't be running the recommended size.
Surprisingly, when reading the side-walls the weight ratings are the same (at different PSI's) 2150 on both (205/D's.. and 225/C's).

My PREFERENCE would be to just pop for another set - this time the 225/D's.. but budget doesn't allow that right now. (unless someone is looking for a set of 205/d's with NO miles on them!).

TIA for responses..

[Dave_Monica]

If the flat is repairable, I'd keep it for the spare and leave it be until the timing is right to upgrade to 225/75/R15 LRD's. Try to sell the 205/75/R14 LRD for as much as you can as they don't offer any more safety margin than the 15 LRC's.

Dave

[woody9]

They're both 15s Dave. just a 205/D - 225/C difference. and that 225 SHOUDL be repairable. Nail smack dab in the center of the tread.
But like your idea.. Anyone need a set of 205's?

[Herk7769]

Let me think about this.

Since you did not specify the manufacturer; I am using the load sheet for Maxxis.

The OEM ST 225/75R/15 Load range C tires are rated at 2150# at 50 PSI.

1) The ones you want to put on it ST 205/75R/15 Load Range D are rated at the same load capacity (2150#) at 65 PSI. So from a Load Supporting perspective there is no difference BUT you won' have the "pad" you were looking for.

2) The aspect ratio of the new tire (75R) is the same BUT with the narrower tread width the tire is shorter.

The new 205/75/15 tire is 8.07 in wide and 27.1 inches tall
The OEM 225/75/15 tire is 8.86 in wide and 28.3 inches tall

Tire Size Calculator

I think it is a safe swap since it will carry the load and physically fit the wheel well. They will rotate more per mile, and will wear out sooner, but should be safe, IMO.

Obviously if you can sell them for a good price and can bear the cost of upgrading them you should look for a 225/75/15 load range D tire to get you that cushion again.

You can repair that radial if it is a center of tread clean punch with an "off rim" repair and should give you great service for the remaining life of the set while you figure out what to do.

[woody9]

Thanks Herc! Those numbers track with what I've found on them both on-line and on the sides of the tires themselves. I think mathematically it works.. but the height will also 'lower' the trailer just a tad.
and yes. loosing that 'extra cushion' IS a concern! that's why i originally wanted to go up a load rating.
Think I need to talk with them @ the local dealer for where I got (Discount Tire - ONLINE).. and see what they might be willing to do as well. AND have them do the 'in the tire' fix.
Thanks!