LT rated tires vs "regular" all-terrains?

Is it just about load rating? I'm thinking of replacing the Dueller Revos on the tow rig, and noticed they have a Revo LT-rated as well as the non-LT ones I have on there now, in the same size. The higher load rating is a plus, but is there any other difference (like rubber compound)? Seems like the LT version is cheaper but has a higher treadwear rating. What's the downside?

The LT version likely has somewhat deeper tread.  It'll have beefier sidewalls and probably feel less flexy.  They will be heavier though. 

I almost always recommend the P rated tires if thats what the oem recommended, lighter, have a mileage warranty (many times the same tire in an Lt looses its mileage warranty), ride better, have enough load capacity for the oe tow rating, and are generally cheaper.

Its a little different with hardcore off roaders, or when for some reason the lts are cheaper.

LT tires have less flex in the sidewall and slightly rougher ride, though they are more capable for hauling and towing than P-rated ones. So if you are hauling heavy loads,  LT is a better choice. I currently run Destination A/T LT275/65R18 on my truck. These Firestone tires are great. Have good road manners and reliable traction.

rslifkin said:

The LT version likely has somewhat deeper tread.  It'll have beefier sidewalls and probably feel less flexy.  They will be heavier though. 

This^^ Plus the ride will be a bit more harsh.  If the tow-pig is also SWMBO's DD it might not be a good idea.

I put a Michelin LT tire on my 4Runner and it now rides rough as hell.  I regret getting them.  My driving is mostly highway and rarely towing.  

I was in charge of the production of both LT and non-LT tire production tire specifications a year ago. The main differences:

• LT tires get a higher load rating
• They get this higher rating because they are designed to hold more air pressure, which allows them to support more load.
• In order to hold more air pressure they have stronger components within the tire and typically more of them. The carcass cords are stronger or more tightly spaced. Sometimes there is a third body ply added. The steel belts below the tread are stronger and sometimes wider.
• The tread depth and compounds are sometimes different as well to account for the different uses.
• This all leads to what has been said above: LT versions are typically stronger, heavier, stiffer, and rougher riding at the same load. But they are great at doing what they were designed for: supporting heavy loads.

The higher treadwear rating on the tires you are looking at may be because the LT versions are only in larger sizes. It's easier to get a high rating with large, wide tires. I'd suggest you stay with the passenger version and leave the LT tires for the 3/4 and 1-ton trucks.