All-terrain tires comes in a lot of shapes and features, and there are some which are definitely worth when it comes to rocks no doubt. So these tires are really good for this type of terrains. Though compared to more aggressive tires like mud-terrain, they are going to lack a little, but the good thing is the margin is pretty low. And considering they are much better than them on pavements, I think that can be ignored.
So basically there are 2 different types of tires P metric and LT. With P metric tires, you get a less stronger inner construction, so these tires aren't able to pick up as much weight, though they get to offer superior fuel economy and tread life in return. On the other side, the LT tires get to be more aggressive and offers superior stability whilst carrying a heavy cargo, or even a big vehicle's weight. In more simpler words, P metric tires are on-road tires, whereas LT are used off road. They are also divided when it comes to load range and ratings as the P metric sizes use the newer metric, which is called load index, where they are assigned with a number (written on the sidewalls), and with it you can tell, how much weight a tire can carry. And with LT sizes, Load rating metric is used which can be cross-referenced with an old bias ply construction as well, that's why its also called ply ratings. Here letters are assigned, going from C, to F, and these tell how much weight a tire can carry (which is more compared to P metric, so these tires are used off-road and for towing).
It does not matter whether it's the Lincoln's head or George's. These test only give you a rough idea in determining tire tread depth. Though if you must, just know that if you insert both of these coins down and their heads are not visible, that in case of penny, that would mean, the tread depth is less than 2/32". And in case of quarter, it would mean, the tread depth is more than 4/32". So you can get a rough estimate, if you are in a hurry by using both of these as 2/32" means replacing your tires right away, where 4/32" means, that you should be replacing tires in the coming time. Though compared to both, its much better if you consider getting a tread measuring gauge.
You can not get a lot of on-performance out of all-terrain tires, as they are not built for that. But still, there are some really unique all-terrain tires, that allow you to go on minor off-road terrains, whilst keeping on-road stability, grip and handling in check. I've mentioned all these tires above. All of them have speed ratings up to H (most commonly), and on one A/T tire, you even get to find a size with V. But still a majority of the tires are what you'd call slow, as their aggressive pattern with ton of biters, and wider grooves, don't allow them to have good enough directional grip, and with it ample speed ratings.
So in order to improve your fuel economy, make sure you have the right kind of tire size first of all. And if you do, make sure you get your tires aligned every 6 months, rotated every 5k miles, and properly balanced as well. Also remove any extra weight form your vehicle, and drive humbly.
When the Nitto Recon Grappler first came in, I though it was a hybrid, and it looks like though it's made out of Toyo RT and Nitto Ridge (both are part of a same organization). But this tire is an all-terrain, though you can say, it's one of the most aggressive A/Ts. That's why it offers better off road traction, with self cleaning tread and superior 3 ply sidewalls durability rendering it better on mud, rocks, and gravel. On the other side, the Terra Grappler is more on road aligned, though still it lacks to it's bigger brother in the wet traction department. That's because it's sipes are more optimized on snow, and its better performing over there, that's why it has the 3 peak mountain snowflake rating (unlike the Recon). Top all-terrain tires, my picks, just one click away: https://tiredriver.com/best-all-terrain-tires/
The UTQG tells you a lot about the tire's traction abilities on wet, and is a way of telling what type of tread it is. Though since the rating is very vague, there's not much you can get out of them, and that goes especially for tread wear rating. A much better way to anaylze your tire's tread wear, is to just check how fast the rubber burns off with a tread wear test. You can do this with a penny.
while tires that have the 3 Peak Mountain Snowflake (3PMSF) rating symbol may provide better traction in snowy conditions than tires that have only the Mud and Snow (M+S) rating symbol, they are not as capable as true winter tires in all types of adverse weather conditions. The 3PMSF rating symbol indicates that a tire has passed specific tests and is designed for use in severe snow conditions. Tires with this rating are typically labeled as "winter tires" or "snow tires" and are made from a special rubber compound that remains flexible in extremely low temperatures. On the other hand, the M+S rating symbol is based on the tire's tread pattern and the materials used in its construction, it indicates that the tire has a tread design that is optimized for better traction on mud and snow and generally considered as all-season tire.
The Wrangler MTR provides good enough grip without compromising on its rolling resistance, so it gets to provide better fuel economy and mileage. Moreover its biters are very efficient in snow and wet roads (comparatively). The Nitto Trail Grappler on the other side offers amazing durability and with it superior off road traction. And although this tire is good enough on dry roads, its wet traction could use a little bump.
Out of both tires, the BF Goodrich provides better wet and snow traction, whereas the Nitto Trail is good enough on dry. And although both tires aren't going to impress in the comfort and other on-road departments, you still get a somewhat better performance on KM3. Off-road things are different, and they both get to have a lot of unique features, and looking at them you can't really tell, which tire takes the upper hand, I've discussed them all.
Compared to all-season, all-terrain tires give out a huge difference in durability, as you can not take a passenger tire on sharp rocky terrains. But even these tires are not completely puncture proof, no tire is, though they get as durable as it gets. Meaning, out of all the off-road tires, the most robust are mud tires, and A/T tires are just as powerful from inside as them That's because on both, the similar 3 ply polyester casing protecting the weakest part of the tire, the sidewalls. Moreover, A/T tires further add to that protecting by offering thicker sidewall lugs, acting as reinforcement. And with larger tread depth, things are similarly made more puncture resistant in the middle. Though there are already powerful steel belts under there, the thicker rubber skin further make it harder for all-terrain tires to get puncture too easily.
Out of both tires, the Cooper Discoverer STT Pro is taking the lead on rocky terrains as its elongated lugs provide the needed lateral traction, and its countless stone ejectors there keep its tread clear. The Toyo M/T on the other side is better on dry roads, providing superior directional grip, and surprisingly being a heavier tire, it get to give you better fuel economy in comparison.