Switching from ST to LT tires

Bill - the weight ratings chart is helpful. It says I need the D rating to get the weight capacity that I would be comfortable with.

I looked at the Discount Tire site again and still don't see the listing for the ST225 size - I even changed locatoins thinking that it might be an availability issue here that was the problem. But even picking L.A. area only showed the ST205.

I may have to call the dealer here to see if he can get the D rated ones.

Thanks for the feedback.
Alan

Originally Posted by Al-n-Sue

I looked at the Discount Tire site again and still don't see the listing for the ST225 size - I even changed locatoins thinking that it might be an availability issue here that was the problem. But even picking L.A. area only showed the ST205.

I may have to call the dealer here to see if he can get the D rated ones.

Thanks for the feedback.
Alan

Alan, I am seeing the same Marathon tires as Bill when I use my home zip. I went ahead and put a California zipcode in, and THEN am seeing only the one tire you are seeing. So Discount may not possibly have it in your area. If you are just wanting to look at the tire (Load Range D), then you might can try my zipcode of 71291.....or even look at Tire Racks page below.

http://www.tirerack.com/tires/Sizes....arathon+Radial

Thanks Bobby - I called the dealer here and found tha the can get the load range D tire, but he said they are more pricey - $124 vs $106 for the C. He said he was selling a lot of the Carlisle tires in the E load range which is a 2830 lb rating ($101). He also said all his trailer tires - even the Marathons - were still coming from China! He thinks that will be changing due to tariffs, but for now, his last load was from China. And he thinks the Marathons are over priced and not as good as the Carlisle.

The Carlisle with the E rating runs at 80 psi - so it seems to me that it is stout enough to handle my 4250 lb TM. I know most/all the reviews I've read on Carlisle say they are terrible. But I wonder how many are running C or D ratings and are not adequate for the rig?

Interested in other comments on the Carlisle.

Alan

I too am getting ready to replace my tires, I'm in Colorado Springs 80919, and was looking at the Maxxis 15" 225 Load range D (they also have an E) the Discount Tire web site showed a price of $119. for the D rated tire. Not meaning to confuse the issue.

All I know about the Maxxis is that I run their tires on my ATV and they are tough as nails. Does anyone know the bolt pattern i should ask for when ordering the wheels?

[Keith Wire]

Hi Redhawk,

Our Modorator, Bill, posted that information a while back.

You can find it here.

Keith

I believe its a 5 on 4-1/2" bolt pattern (5-114.3mm / 5-4.5")- that's what was on my 2619.

Getting back to what the OP was concerned about: 65 mph max, I found the following in the "Goodyear (Marathon) Recreational Vehicle Tire and Care Guide". Has anybody tried raising their tire pressure to 75psi (if your wheel allows it) so they can go 75 mph?

I will never try it. 65 mph max. is fine by me. Just curious.

BEGIN QUOTE
IMPORTANT OPERATING INFORMATION
Industry standards dictate that tires with the ST (Special Trailer) designation are speed restricted to 65 mph under normal inflation and load conditions, unless a different speed restriction is indicated on the sidewall of the tire. Based on industry standards, if tires with the ST designation are used at speeds between 66 and 75 mph, it is necessary to increase the cold inflation pressures by 10 psi above the recommended pressure for the load.
• Do not exceed the maximum pressure for the wheel.
• If the maximum pressure for the wheel prohibits the increase of air pressure, then the maximum speed must be restricted to 65 mph.
• The cold inflation pressure must not exceed 10 psi beyond the inflation specified for the maximum load of the tire.
END QUOTE

Another quote to explain why 65 mph is fine by me:

BEGIN QUOTE
Effects of Higher Speeds
• When traveling at 65 mph vs. 55 mph, tires will experience a 15% tread life penalty (30% at 75 mph)
• Trucking fleets report fuel economy losses of about one mpg for every ten mph over 55 mph (a 15% loss)
• Longer breaking distances (SAFETY ISSUE!)
• Reduced handling ability (SAFETY ISSUE!)
• More fuel stops due to reduced fuel economy
• Tire load-carrying capability decreases as speed increases
END QUOTE

[Bill]

We've talked about it. It seems that no one is positively sure what those words mean. For one thing, the words "10 psi above the recommended pressure for the load" seems to suggest that you can/should raise the pressure beyond the MAX PRESSURE stated on the sidewall. I'm not comfortable with that, for sure. Or perhaps it means that if the tire is so lightly loaded that you are running at 55 psi, then you can increase the pressure to 65 psi (still within the sidewall rating) and run at 75 mph if you maintain the same very light load. It is just a bit ambiguous to me, anyway. And no one I know runs at a very light load.

And then, the words "Tire load-carrying capability decreases as speed increases" tell me that the tire will carry less if you are running fast - but it doesn't tell me how much less. Is it less than the "very light load" mentioned above?

Bill

• Tire load-carrying capability decreases as speed increases

Yes, I was wondering just what that meant. Pretty ambiguous.

Thanks,
Bruce