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.
Out of both the Nitto Trail Grappler supplies superior dry grip, whereas the Cooper STT Pro is better with wet and snow traction. And besides, that you can't really tell which tire is better as it gets complicated with other performance sections.
Both mud terrain tires offer premium options for your heavy duty trucks, though still out of them, there are a few areas, where we saw one tire performing better than the other. The BF Goodrich KM3 provides one of the best traction when it comes to sand, and other than that, the tire does great on mud as well comparatively. It's winter traction is also superior, and so is it's fuel efficiency and comfort capability. In comparison the Toyo Open Country M/T offers better dry grip, tread life, and rocky terrain traction.
Out of both tires, the Nitto Trail Grappler takes the lead when it comes to dry handling and rocky terrain traction, and on other off-road areas, its almost on par with its competitor. The Pro Comp M/T2 on the other side, is very surprising when it comes to tread wear, as the tire produces minimal rolling resistance, and with yields better fuel economy. Moreover, you also get to see better snow traction and wet road performance on this tire.
On Cooper STT Pro, you are going to see better rocky and sandy terrain traction off-road, and on pavements, a better grip, but only on dry. The Yokohama M/T on the other hand, provides better all season traction, so it's not only better in wet, but also in snow. And off road, although it lacks on rocks and sandy dunes, it's mud traciton is on par with its competitor.