Trailer Tires Speed rated ?

[Chuck N. Wined]

Is there a 15in LT tire that will work on a trailer? I really don't want to swap out wheels to move up to a 16in tire but that seems to be the only option if I want to go LT.
Lonnie

[WildWildWest]

Interesting discussion. Here's my 2 cents. Take it for what it's worth.

ST tires are rated for 65 mph. If you occasionally tow at this speed or higher - some interstates at 75mph, make sure you are inflated to max pressure cold. IE. load range C 65psi, Load range E 80psi.Cold pressure can be increased by 10lbs over max if you constantly drive 75mph (as long as your wheels are rated for it - I don't do this). This higher pressure doesn't increase weight capacity and could cause premature wear but actually less likly to blow out at high speeds due to less heat.Assuming your tire is matched closely for the load, you wouldn't run them below the max pressure recommended for any reason or your tires will start to generate heat from flexing. If your tires are in fact rated significantly greater than your load then you can reduce pressure without affecting performance. Max inflation also reduces sway by maintaining a stiffer sidewall.

I strongly suggest you weigh your trailer before reducing tire pressure. Fully loaded with food and fresh water and potentially some black and grey tank weight - normally you will find your trailer very close to or slightly above gross weight rating. They don't put axles or tires on these units that are rated significantly higher than their designed load carrying capabilities due to cost.

I know we don't travel light and I have surprised myself at the scales before when I haven't expected to be near max weight and usually very close if not at max weight.

LT tires on a trailer are a different story. Can be run at slightly lower pressure as long as matched for weight. IE. light weight an E rated tire can be run as low as 55PSI. Normal is 65psi minimum and for heavy load carrying, keep them at 80psi - rated higher than required at this inflation but it won't hurt - LT E rated tires are designed for this pressure. Tires will wear better and heat up less under load if at appropriate pressure.

Obviously D rated and C rated tires have lower max pressures and also lower weight ratings.

Myself, I run 80psi in my ST tires and I only have 5,200lb axles - tires at that pressure should handle 3,200 to 3,400lb of weight at each corner on the trailer which are obviously higher than the axles are designed, but better safe than sorry and less flexing and less heat and since I tend to drive 65 to 70mph, I don't plan on reducing pressure. If I move up to LT tires for my trailer in the future, I will still run them at 80psi. If I find them wearing more in the centre at that time I will reduce the pressure to 70psi, not likely lower.

[Hunter11]

Scott, are you sure you only have 5200# axles on your unit? I only ask because under the "standards and options" of the Cruiser Patriot it list 5200# and 7000# axles. Since your unit is one of the larger Cruiser floor plansI would suspect you have larger axles. I would think at a minimum they would use 6k axles on the Cruiser Patriots. I may be wrong because ithas beenseveral years ago we owned it but I think our old 05 Cruiser 29RK had 6k axles.

[WildWildWest]

I'll check it- could be wrong on that one - but I thought I read somewhere 5,200lb axles - which is pretty much maxed on my unit.

Now I'm going to have to crawl under it and look! I would prefer 7k axles, but I'm pretty sure they aren't rated that high.

[Hunter11]

I would think 5200# axles would be under rated for any of the Cruiser Patriot line. I would think they would use 6k minimum.

[WildWildWest]

Originally Posted by Hunter11

I would think 5200# axles would be under rated for any of the Cruiser Patriot line. I would think they would use 6k minimum.

You would think so, but I was under there on the weekend and I dohave only5,200 lb axles on my unit. Considering a 12,300 lb max weight loaded, they don't give you any breathing room.

[Buddy]

Originally Posted by b727capt

I have a new 33BD TTand have a question about the tires. Some other forums claim that trailer tires are speed rated to about 60mph. I have looked at my tires and I do not see any limitation. I normally tow about 60-65 to help with MPG and sway, but occasionally get on a 70mph interstate. Are the tires speed rated? Is 70mph safe for the tires?
Thanks,
Happy Camping

I am retired and not in a hurry, taking my time and enjoying the ride and scenery. I drive 55 top speed.

[NH Horseman]

My Zinger tires have the pressure marked on the side, 50 PSI.
But, the camper specifies tire inflation to be 65 PSI.
These are the original tires.
I am running them at 50 which is what they were when I bought the new camper.
They are nitrogen filled, if that makes a difference?