Help me understand Tires, LT vs P?

[Ronbo]

So, can someone help me understand these tire ratings?
I have, what appear to be, "P" tires on my FX4, that came from factory. I see that lots of people are trading up to an LT tire, which I guess is supposed to provide more plys which makes the tires sturdier and less prone to puncture or have a blow out? (Am on the right page so far?) So I am looking at the LT version of the very tire that I have now, the H/K AT-M's, in the same size, etc, Tread pattern, side lugs, etc, are all identical. I see that the even though the LT tire has a "C" load rating, it appears to be about 200 lbs less load capable than the load rating of the "SL" Standard Load tire. 2469 pounds on P "SL" tire, and only 2270 pounds on the LT "C" tire. Plus the LT tire is about 7 pounds heavier per tire (which affects MPG's). It would seem to me that solely based on the maximum load rating, the P tire would be better, no? What am I not understanding?

Dynapro ATM 265/65R17 Tire Specs

Size	Diameter	Width	Rim Range	Measured Rim	Tread Depth	Load Range	Max Load	Max psi	Max Speed	Weight	Sidewall Letters	Revs/Mile
265/65R17 112T SL OWL	30.6"	10.5"	7.5-9.5"	8"	13/32"	Standard Load	2469 lbs	51 psi	118 mph	37 lbs	Black/White Option?	679
LT265/65R17 109T C OWL	31"	10.6"	7.5-9.5"	8"	13/32"	C - 6 ply	2270 lbs	50 psi	118 mph	44 lbs	Black/White Option?	675

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[Scoops14]

Google is your friend: https://www.tires-easy.com/blog/p-metric-tires/?amp

 

[HenryMac]

This does a good job of explaining the differences... the answer to your question is basically that they are not designed using the same set of rules

LT Tires vs. Passenger Tires

 

[SandBaja]

Tire sizes can be confusing as there are so many factors.
I found these helpful in decoding the Hankook ATM's 265/60r18 110T
https://www.tirebuyer.com/education...ratings-load-indexes-and-service-descriptions
https://www.tirebuyer.com/education/understanding-tire-sizes-and-types

 

[I_smell_like_diesel]

This will hit the nail, directly on the head for you (or anyone else wondering the same).

https://m.tirerack.com/tires/tiretech/techpage.jsp?techid=195

Theres also a big difference on load ratings and required air pressures for LT and Pmetric Tires.

Example: My truck was spec'd for P265/60R18 @ 30psi. I now run a 10ply LT275/65R18 but to get that tire within to same load carrying specs for daily driving, I have to run that tire at a higher pressure.... about 40 psi to meet match the OE tire load rating.

 

[Subduction]

As a trivia note: the ply rating is not necessarily the actual number of plies; modern materials allow fewer layers to be used.

 

[Sashimi_Moto]

Yup - different rating systems so it's nice to be able to reference the the Load Index to make sense of it.

It's sort of like Treadwear. There's guidelines, but what might be 300TW to one manufacture might another's 500TW.

 

[Hounddog409]

The ranger cannot tow or haul enough to need LT tires.

There is absolutely no reason to think you need LT's.

LT's are also much heavier and will wreck your MPG. By alot.

 

[HenryMac]

The ranger cannot tow or haul enough to need LT tires.

There is absolutely no reason to think you need LT's.

LT's are also much heavier and will wreck your MPG. By alot.

Our truck has LT tires, dealer ordered it that way.... it's a Wyoming thing I guess?

Our 2019 Ranger is averaging over 25 mpg, in a FX4.

 

[RoadBoss]

The ranger cannot tow or haul enough to need LT tires.

There is absolutely no reason to think you need LT's.

LT's are also much heavier and will wreck your MPG. By alot.

That's a pretty broad statement.

I have E rated LT's, I still managed to get 25-27mpg highway when everything else was still stock.

I will continue to get E rated tires because I have a lot of weight in my truck, and will be traveling long distances to remote areas, over extremely varied terrain. A blowout could be catastrophic, so having tires that are durable is key.
adding up all the numbers, could a P tire handle it? technically yes. but an LT tire is going to be a lot less stressed, and most likely more reliable. not to mention there are a lot more tire options in LT.

all other factors the same, will a little bit of extra weight hurt fuel mileage? yes, but will it be enough for most people to notice? probably not.

It's worth looking into what you actually want to use your vehicle/tires for before you blatantly say "STAY AWAY".

 

[SilverSlugger]

This will hit the nail, directly on the head for you (or anyone else wondering the same).

https://m.tirerack.com/tires/tiretech/techpage.jsp?techid=195

Theres also a big difference on load ratings and required air pressures for LT and Pmetric Tires.

Example: My truck was spec'd for P265/60R18 @ 30psi. I now run a 10ply LT275/65R18 but to get that tire within to same load carrying specs for daily driving, I have to run that tire at a higher pressure.... about 40 psi to meet match the OE tire load rating.

I know I'm bringing a very old thread too life but... did you feel like the 275/65 18 is too heavy for the Ranger? This is my concern right now, I'm eyeing up a 285/65 18 K02 with a 10 ply rating.

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