Steers Tires- Speed rated M or N

Well there’s no doubt that dump truck 385 steer tires are forever wearing out the shoulders while the middle has quite a bit of meat left. I’ve got several sets in the barn, of various brands, that look just like that. Can’t bear to throw them away, but I might as well because they’ll never be used again. On the other hand, I ran a sleeper truck with 455 wide base drive tires- Michelin in this case- and they wore evenly for many, many miles. Still running them on a local haul dump trailer and have some life left. Why the difference with the wide steer tires?

 

Wide steer tires also take a ton of side loading on the shoulders especially at highway speed compared to a drive/trailer tires that mostly just goes straight.

I have 425s on the front of my truck. Factory Bridgestones lasted 160K miles. I switched to the Michelin XFE when I replace them and have about 130K on the Michelins. When I get some time I'm going to flip the tires on the rims. The inside shoulders have a lot less wear than the outside for me. I'd like to see just how long these can last. I'm hoping to get to at least the same 160K but wouldn't mind if they last longer. Still tons of center tread left.

My left steer does have about 40K less because the first one had a defect that caused the tread to start separate. When the passenger side gets worn out I'll replace both and just keep the drivers side as a spare in case something ever happens to one of them.

 

Simply put, steering.
Drive tires run straight, so it's not as pronounced as steering tires, but it's still the same concept.
Curves and general turning of the steering wheel makes the steering tires "lean" more, which accelerates the wear pattern even further as the steering axle is "off vertical" because of the camber, which aids manouverability at the sacrifice of tread face edge wear...
The camber increases the centrifugal force and speed variation, therefore accelerating the wear pattern.
When drive tires "turn", they stay vertical and it's the flex in the suspension bushings that allows them to compress on the inside and stretch on the outside to rotate, but the camber always stays vertical, especially at road speed in curves n such...
That's why (in North America, RH travel lane), the left side tire always wears more and faster than the right. Right turns, and curves are always tighter. The left turn and curve has an extra lane, so corners aren't turned as aggressive, and curves have an additional ~12' of radius, so they're more gradual...less aggression transferred to the "heavy" steering tire shoulder...

 

Been trucking for 38 years and never have I seen it put so well thank you for your knowledge and passing it on to the rest of us.

 

Thanks!
It's extra special when one gets a compliment like this from someone with many more years experience than oneself, I'm humbled sir.

 

Seen a vac truck on 63 a couple years ago that blew a wide base steer. Kept it on the road but there was no fender, half the side of the hood gone, bumper crinkled and I think it walloped the fuel tank pretty good too. A lot of mass plus a lot of speed equals major damage.

 

Was it truck stop tire shop that told you this? I've had lots of shop techs tell me something is illegal when in fact it is not.

Techs are taught industry accepted best practices(or rather what their big chain claims is best practice), not dot regulations. Next time a tech tells you something is illegal get your green bible out and ask him to show you the dot code on it. Chances are he doesn't even know how to look it up in the green book let alone knows what it says.

 

If the two different brands had different ratings, I could understand it.
If the size and ratings are equal, I don't think I could accept that.
I'd like to see the citation code, and regulation for it.
Pretty sure I'd challenge that one in court.

 

He said it went flat and had to get two from road service. Sounds to me like he got screwed by a tire shop. Not the dot.

 

Wide tires don’t wear good if you don’t keep enough weight on them. I run 385’s with my old trailer 11 or 12k is all I could get on them. They wore horrible. With the new trailer I keep 14 to 16k on them at all times. They wear good and flat now. High speed and low weight is really bad on the shoulder wear.