Need new tires

[TMT]

I have a new to me '78 Tradewind. Among many things that need to be improved, the tires are a must-do-now. There are 2 sets of different tires.
(2) Kelly P215.70R15, and (2) Firestone P205.70R15. The Kelly's look almost new, but the Firestones are much older, and one looks like it's a bit dry-rotted.

Having read numerous posts here, I really don't know what to buy.

Can someone please help?

Thanks,

TMT

[DKB_SATX]

I like my Michelin XLT M/S2 in P235/75R15 XL. I note to my concern that Michelin shows this as "limited availability" (I'm concerned since I don't feel that our light '70s trailers need the extra capacity you get from 16s, hopefully they'll keep producing this size).

Of course ST tires are an option, but I think the Michelin is a better tire and has more than ample capacity for my trailers and yours.

[overlander63]

Originally Posted by TMT

I have a new to me '78 Tradewind. Among many things that need to be improved, the tires are a must-do-now. There are 2 sets of different tires.
(2) Kelly P215.70R15, and (2) Firestone P205.70R15. The Kelly's look almost new, but the Firestones are much older, and one looks like it's a bit dry-rotted.

Having read numerous posts here, I really don't know what to buy.

Can someone please help?

Thanks,

TMT

The answer is, neither. The tires that are supposed to go on your trailer are either 225/75 15, or 7.00x15, both in load range D. Neither of the tires you are asking about are the correct size or load range. If you really want a lighter-duty tire, you can see if you can find the above-referenced Michelin LTX in 235/75 15, load range C, but that is still far beyond what you are considering.

[TMT]

I can and will replace all 4. Just need to know what to replace with.
Size, load range, etc. Doesn't have to be a trailer tire, but does need to be the correct tire! :-)
Thanks for any and all advice!

[CapriRacer]

Originally Posted by TMT

I can and will replace all 4. Just need to know what to replace with.
Size, load range, etc. Doesn't have to be a trailer tire, but does need to be the correct tire! :-)
Thanks for any and all advice!

First, we need to establish what the original tire size was. I'm a tire guy, not an Airstream expert. So someone with historical background needs to step in here.

Second, I don't have a good feel on how well older Airstreams were relative to tire sizing. Other trailer manufacturers were either marginal or even undersized.

Personally I would weigh the trailer - fully loaded, water tanks full, everything you can possibly think of that you would carry. You are looking for a worst case.

What you are looking for is the highest tire loading - which means you need to weigh each tire individually. If you can't, I'd recommend adding 10% to the axle values or 15% if you weigh both axles at the same time.

I also recommend not loading the tire to more than 85% of the rated value.

In all likelihood, this is going to require more work than you anticipated, but in the end, a single tire failure causes much much more headaches. You want to avoid those at all costs.

[Lumatic]

Your tire type should either be special trailer tires ST or light truck LT not regular car tires. You can tow a LT tire at a higher speed without overheating.

Also tire condition cannot be assessed by appearance alone. Trailer tires are occassionally used and often look good. The consensus is a tire over 5 years old has begun to deteriorate. There is a month and year stamp on the side wall of each tire which will tell you when it was manufactured

[Ridgerunner3]

Many here use Michelin LTX P235 75 15 XL on their trailers. Andy at Can-Am Airstream recommends them to his customers.

I put these tires on our trailer after listening to people like Capriracer & Andy. Have been very happy with them.

[Bill M.]

Either the Michelin XLT M/S2 in P235/75R15 XL or the Goodyear Marathon ST tires would be a very good choice. My opinion is that if you are going to pull it a whole lot, as in months and months and thousands and thousands of miles a year go with the Michelins. If it is going to sit mostly and just be pulled some go with the GYM. The Michelins will be around $700, the GYMs around $500. Get them balanced. If you are ever going to add a TPS get the correct valve stems for that.

[ROBERT CROSS]

Many good reviews with these....no 16" wheel up-grade needed.

Bob

[overlander63]

Originally Posted by CapriRacer

First, we need to establish what the original tire size was. I'm a tire guy, not an Airstream expert. So someone with historical background needs to step in here.

s.

I already did, and the OP chose to ignore it.

[ROBERTSUNRUS]

Originally Posted by ROBERT CROSS

Many good reviews with these....no 16" wheel up-grade needed.

Bob

Hi, on this link, the tires are listed as a "P" tire and described as light truck tires???????????

[ROBERT CROSS]

Originally Posted by ROBERTSUNRUS

Hi, on this link, the tires are listed as a "P" tire and described as light truck tires???????????

Robert,

When I first noticed that, I jumped to the spec sheet to check the load rating.

Bob

[LFC]

I believe both of these are D rated.

http://www.ebay.com/itm/4-NEW-205-75...623814&vxp=mtr

4 New 225 75 15 Goodyear Marathon Radial Trailer 75R R15 Tires | eBay

[TMT]

Originally Posted by overlander63

I already did, and the OP chose to ignore it.

Was there a question here to me?
I'm not sure.
Thanks for your help.

[Bill M.]

The Michelin LTX tire for SUV's and light trucks is a P rated tire with an XL load rating. They are rated at around 2135 lbs at 50 psi. You need to down rate the load by 10% for a trailer application. (comes out to 1985 lbs) Much different from a P tire that is only rated to 35 psi. Michelin used to offer a similar LTX tire that carried a LT C rating (50 psi). They dropped it. I am not suggesting using any other P rated tire and would not use any other P tire. But the Michelin LTX XL works fine on my trailer. Works just like the C rated LTXs I had on before. Michelin does not endorse any of their 15" tires for trailer use. I have run the LTXs for 6 years now, 5 on the LT C tires and 1 on the P..XL tires and still like them. If you are not sure you will, just get the GYM's and check them regularly, And you will know that you are using the "right" tire for trailers.

[CapriRacer]

Originally Posted by TMT

Was there a question here to me?
I'm not sure.
Thanks for your help.

Yes. The question was: What was the original tire size on the trailer? Overland63 thinks they were either 7.00-15's or ST225/75R15's.

But I'm not satisfied with that answer because a 7.00-15LT has a load carrying capacity of 2040# at 65 psi, while an ST225/75R15 is 2540# at 65 psi (Both Load Range D)., while an ST205/75R15 LR D's is 2150# at 65 psi.

Originally Posted by ROBERTSUNRUS

Hi, on this link, the tires are listed as a "P" tire and described as light truck tires???????????

Robert,

There are passenger cars and there are light trucks, - AND - there are Passenger car tires and LT tires - BUT - in the cross over, there is a mix. Large PC tires are used on light duty light truck vehicles - hence the description. (But it never occurs that LT tires are used on PC vehicles)

To eliminate the confusion, it is common to use the phrase "P metric" and "LT metric" when describing tire sizing. P metric tires come in "Standard Load (SL)" and Extra Load (XL)", while LT tires come in Load Ranges (C, D, E, etc.) although you will hear people say "ply", as in "6, 8, or 10 ply" (where 6 ply rating = Load Range C, 8 PR = LR D, etc.)

Those 2 types of tires are quite different - and as has been pointed out, in order to use a P type tire on a LT vehicle(which would include trailers) the load rating has to ben decreased by a factor of 1.1.

[TMT]

Originally Posted by CapriRacer

Yes. The question was: What was the original tire size on the trailer? Overland63 thinks they were either 7.00-15's or ST225/75R15's.

But I'm not satisfied with that answer because a 7.00-15LT has a load carrying capacity of 2040# at 65 psi, while an ST225/75R15 is 2540# at 65 psi (Both Load Range D)., while an ST205/75R15 LR D's is 2150# at 65 psi.



Robert,

There are passenger cars and there are light trucks, - AND - there are Passenger car tires and LT tires - BUT - in the cross over, there is a mix. Large PC tires are used on light duty light truck vehicles - hence the description. (But it never occurs that LT tires are used on PC vehicles)

To eliminate the confusion, it is common to use the phrase "P metric" and "LT metric" when describing tire sizing. P metric tires come in "Standard Load (SL)" and Extra Load (XL)", while LT tires come in Load Ranges (C, D, E, etc.) although you will hear people say "ply", as in "6, 8, or 10 ply" (where 6 ply rating = Load Range C, 8 PR = LR D, etc.)

Those 2 types of tires are quite different - and as has been pointed out, in order to use a P type tire on a LT vehicle(which would include trailers) the load rating has to ben decreased by a factor of 1.1.

I am so sorry. Didn't read correctly.
Yes, you are correct in that they were 7.00-15's.
Thanks to everyone for their insight.