Tires: Driving 70 - 75 MPH - LT or ST?

[timetogo]

Carlisle Tire says: Today, some of our tires are "rated" (speed symbols) at 87 mph (N), some at 75 mph (L), some at 65 mph (J: ST tires) and some at 62 mph (J: non-metric tires).

There may be other ST tires available with speed ratings higher than 65.

[04266832]

Thank you all for the responses so far. I post here because I appreciate the knowledge and experience on this forum and that's what I got.

It looks like I'll be going a different route than I thought. I'm going to start researching an upgrade to 16" 6-lug wheels with LT tires specifically for trailer applications.

Thanks again.

[TDI-Minnie]

Originally Posted by lanerd

Why is it not safe?
Ron

I though my point was pretty clear. If the concept of safety through similar relative speed is hard to understand, I can't help you. I was specifically talking about areas where the speed limit is 70-75mph, which is much of the country today.

Unless there is a dedicated third lane for slow moving vehicles, anyone going 10+mph under the speed limit is a hazard.

To the OP, Maxxis are great tires. I would buy them over Goodyear or any others that are currently available, unless you go with LT, which is OK if you rarely make sharp turns on pavement. Going to a 6 lug gets into a whole other realm. Obviously you are now getting into new axle/hubs, etc.
Best of luck. Let us know what you decide on.

[NFlcamper]

My useless opinion is that the manufacturer has a built in buffer of about 10% for speed. The tires will not disintegrate at 66 mph if they are rated at 65 mph. A 10% margin for 65 mph tires is 6.5 mph and added to 65 is 71.5 mph. I often have to accelerate to 70 ish when passing with my trailer even when I have my cruise set at 65 mph to keep from being in the express lane and causing a rolling roadblock while passing. My TT is 9,400# and I keep it under 72 as my personal speed maximum, since I consider it heavy.


I will now tell you of personal experience traveling long distance towing a trailer with ST tires. I went to Sturgis, S.D. for the bike rally in '13. We towed at speeds from 65 to 75 varying speeds for traffic and conditions when we were going north from Florida. No problems going, but on the way back in the long desolate interstate highway of S.D. and Iowa, the other driver I was buddy traveling with got in a hurry to come home and had us traveling 75 to 80 mph. I got in front of him after a fuel stop and he noticed a wobble look in one of my ST trailer tires. He called my phone and had me pull over in a rest stop and we discovered that the tire was separating - the tread from the carcass. I changed tires and refused to exceed 75 mph from then on and I contribute the speed as the reason the tire was coming apart. This was a 8x12 single axle enclosed box/bike trailer carrying 2 motorcycles and camping gear. Same tires are on the trailer today, 2 years later, and that is from Iowa to Jax., Fl. and lots of local trips and at least 1 trip from Jax to Key West, and another to N.C. and back a buddy did borrowing my trailer. I went up to 75 going to the Keys and told my friend NOT to exceed 70 with my trailer borrowing it. I consider myself lucky as I have seen what a blowout can do to trailers. I see fenderless cargo trailers all the time, just look around, they are easy to speed with, while towing. A friend had to repair his toy hauler when a tire took out the bottom of his trailer. He is the SAME one that had us going 80 mph from Sturgis! Mmmm, Anyone else see a pattern?

On a side note, I have upgraded both TT and cargo trailer tires to a higher load rating than what they came with. I prefer a cushion rather than riding at the edge of a tires rating. A good bump can cause a tire to see weights exceeding its rating, and do damage internally that may not show for miles down the road or days or weeks later.

[JIMNLIN]

It looks like I'll be going a different route than I thought. I'm going to start researching an upgrade to 16" 6-lug wheels with LT tires specifically for trailer applications.

I don't know of any 16" LT E tire made specifically for a trailer position.

I just looked at your profile which shows a '16 Keystone Bullet Premier 30 RIPR with a 8200 GVWR.

Your ST225/75-15 D have 2540 lb capacity and are 28.3" diameter.
A LT225/75-16 E has 2680 lbs capacity and are 29.2" diameter which will make your tires 1/2" closer. Dexter axle says a 1" minimum.
The LT225/75 will give you a huge 10720 lbs of capacity.

Here is a list of LT tire lines that has been recommended by their manufacturer for using on trailers.

The top two are the Michelin XPS Rib and the Bridgestone R-250 both being a commercial grade tire with a all steel ply carcass. The R-250 is lower priced vs the XPS tire.
Goodyear Wrangler HT
BFG Commercial T/A2 AS
Cooper HT3
Firestone Transforce HT
Uniroyal Laredo HD-H

A LT tire maker may have several lines of LT tires but usually have one line they recommend for a trailer position. Tread pattern and internal reinforcing belts/material types/etc can be reasons they recommend just one particular line. Generally the tread will have at least one or more solid rib for straight line tracking.

[1bigmess]

Originally Posted by TDI-Minnie

If the concept of safety through similar relative speed is hard to understand, I can't help you.

My current trailer tires, ST tires, the ones that came on it when brand new, are rated for 65 MPH. Sorry, but I can't go any faster than that when towing. There are also states with split speed limits that keep different vehicles at different speeds under threat of force.

I guess I have to depend on others to drive safely around me due to the fact that I will not go faster than my tires are rated to carry my vehicle.

[Chuck 1935]

[QUOTE=1bigmess;2699147



I guess I have to depend on others to drive safely around me due to the fact that I will not go faster than my tires are rated to carry my vehicle.[/QUOTE]


You are absolutely right to not exceed the speed rating for your tires.
I wonder how many folks are aware of their tires speed rating ?

[1bigmess]

And I think that is part of the problem of many vacations or movements of RVs and other things. SOme folks go as cheap as they can, and suffer the consequences when they are oblivious or ignorant to the limitations of their equipment, and I mean all of their equipment. Tires, brakes, suspension, loading (even, uneven, poor or no weight distribution, ad infinitum, as nauseum), weather, road signs, on and on and on.

I depend completely on my tires to keep me going down the road. I won't abuse them or make assumptions based on something that the manufacturer of my tires did not implicitly say (10% fudge factor on speed ratings? What if the fudge factor is a downward adjustment, and not UP?)

If someone gets behind me on a two lane road and is frustrated with how I'm driving (within equipment and legal limits), that is their problem. If it's you, it's your problem. If I'm in the right lane of a multiple lane highway going less than the speed limit due to some real limit of my equipment, than I am following the law as long as I am above the legislated minimum speed limit in that state. Any problem anyone else has with that is their problem.

I know my trailer tires are speed rated for 65mph MAX. It's the same speed rating in AZ, CA, WA, BC, etc. Sorry folks, driving over that rating is dangerous, not "keeping up with the flow of traffic". It's my trailer, I decide what risks to take, and my mind is made up by knowing what I am capable of, what my equipment is capable of, and what I am capable of on the road I'm on, and I will stay on the safe side of those limits at all times. You are more than welcome to safely pass me if you are able, and if not then sit back and enjoy the view. I am.

Flame on, I can take it.

[Mr_D]

Originally Posted by Chuck 1935

TDI-Minnie ,
Very wise advice. These folks are the very reason so many people do not like Motorhomes on the Highways. These are the same drivers that proudly announce that their "sweet spot" is 53 7/8 MPH . Whether that are incompetent , timid or just plain afraid, the results are the same. They are creating a danger on the Highways. On the two lanes, they are the folks who selfishly have a line of vehicles behind them.
I am sure I will get blasted by the 53 7/8 group but if it raises awareness to be a bit more considerate of your non RV travelers it was worth it !

Tell that to CA since an RV pulling anything or anything towing a TT or 5th wheel is limited to 55 mph and they LOVE to enforce it. First ticket in almost 30 years came earlier this year for 67 in a 65 zone, but I was towing our Odyssey at the time so 12 over and $467 fine. Can't appeal it either due to the distance and needed to appear twice.

[1bigmess]

And 12 over could really hurt your insurance rates for years to come.

Ask the county clerk for traffic school if you can, and stay out of CA for two years, and you might be OK.

[04266832]

Just to be clear, and not stray off topic, I never insinuated I'm looking to drive over the posted speed limit or exceed the ratings of my equipment. Instead, this question is to do the exact opposite: be able to safely travel the posted speed limit and select the correct equipment rated to do so.

Again, thanks for the helpful links and suggestions. It does help to further research.

[IdahoSRT10]

If money is a concern and you want a great tire go with the Maxxis E rated ST. It's one load rating over your OEM and a much better quality tire. (make sure your wheels can handle 80 psi.) I've compared the LT to the ST side by side with the ST being heaver, thicker sidewall and a higher load rating.

[JIMNLIN]

I've compared the LT to the ST side by side with the ST being heaver, thicker sidewall and a higher load rating

So have I on many occasions when buying tires for my heavier equipment/flatdeck trailers.
Better look closer as a ST 235/80-16 E weighs from 37 up to around 41 lbs depending on brand vs a LT235/85-16 E that can weigh up to 56 lbs depending on brand.

[tuffr2]

My LT Michelin XPS Ribs were way heavier than my China bomb ST tires.