The blizzard was somewhat unexpected. I woke in Breckenridge, Colo., to 8 inches of fresh snow and more in the air.

　　Id planned to go skiing, but a stomach bug and a pending chore stymied my plans. I needed to get up to Leadville to grab some gear for a buddy, and the roads would be horrible. Oh well, I thought. At least I have good tires.

　　An hour and a half later, I found myself rolling up an unplowed street in Leadville. The drive had been uneventful, which is remarkable given the nasty, snow-covered roads. Sure, having an F-150 with four-wheel drive helps. But when it gets down to brass tacks, what matters in bad conditions is where the rubber meets the road.

　　And, in my case, it was on a set of Cooper Discoverer AT3 XLT tires with 10,000 miles. This is my impression of driving on them for 6 months.

　　UPDATE: Its been 4 years since GearJunkies initial review, and in the meantime, Ive racked up an additional 40,000 miles. Hop to the end for additional impressions on longevity, durability, and a lot more on our 50,000-mile test below.

　　For complete transparency, Cooper sent me this set of tires for testing. But, Im going to do my best to talk about them neutrally for those shopping for tires.

　　In short: The Cooper Discoverer AT3 XLT is a rugged all-terrain tire that should stand up to anything most people throw at it. While there are more aggressive tires, these provide good on- and off-road traction while remaining quiet at highway speeds. My only negative is that they are heavy, cutting fuel efficiency significantly, even in my F-150.

　　Shopping for AT Tires? Check out our guide to the Best AT Tires here. Spoiler: the Cooper AT3 XLT is our top choice!

　　Cooper Discoverer AT3 XLT

　　(Photo/Cooper Tires) Pros Handles well in the snow Sizing to fit a wide range of vehicles Great value 3-Peak Mountain Snowflake rated and pinned for winter studs Cons Wet grip has room for improvement Road noise not too loud but perceptible and has a distinct tone on the pavement Sean McCoy check price at amazon Cooper Discoverer AT3 XLT Snow Performance As a Colorado resident who spends a ton of time in the mountains, winter performance in tires is a high priority. I got stuck on a set of stock all-weather tires on shallow but slick snow on my first day with my new truck, and I didnt want that to become the norm.

　　These tires are severe weather rated, meaning they perform at least 10% better than standard all-season tires. They carry a mountain-snowflake symbol as proof. For me, the proof was on the road.

　　The Discoverer AT3 has proven very capable in the snow. Ive driven on snowy, icy roads about a dozen times so far this winter. In deep snow, and even hardpacked snow, the truck grips the ground well. Things get a little trickier on ice, but for an all-season tire, it still inspires good confidence.

　　It does this thanks to rugged lug design and significant siping that helps it grip, even on slick surfaces. Ive had a few instances of tires spinning from a dead stop on an icy hill, though, so they arent perfect.

　　Obviously, a winter tire could probably perform better. But I, for one, cant afford another set of 33-inch tires for the season, so these will suffice nicely.

　　Discoverer AT3 Off Road I think this is where most people will really like this tire. I used it over a fall of hunting in the Rocky Mountains on a mix of gravel roads, muddy trails, and modest rock trails. The tire was never a weak link.

　　Parked at a trailhead for an elk hunt (back of the truck loaded with elk quarters) I want to qualify this section with my goals for an off-road tire. My truck is a 2010 FX4 with just 30,000 miles on it. Its in amazing condition for a 10-year-old vehicle. And as such, Im not taking it rock crawling on super-sketchy terrain.

　　That said, its no pavement princess. I get it in some pretty weird, remote places on roads that will instill white knuckles in most drivers.

　　One such slightly challenging drive was up to South Colony Lakes in the Sangre de Cristo mountains. Its a modest trail, and most 44 vehicles should make it fine, but it does require some attentive driving.

　　These tires ate it up like it was flat ground. Clawing over some steep rocks and lots of baby-head rocks, they performed wonderfully. They showed no signs of wear even though there were lots of rocks poking at them over the 8-mile round trip.

　　I havent run these tires aired down yet and havent needed to lower the tire pressure. If youre looking to rock crawl in a Jeep or take them on super-serious trails, well, sorry. I just dont have the vehicle for that kind of testing. My guess is that theyd work great, but I cant be sure.

　　Discoverer AT3 on the Highway Lets be honest: This is where your tires will be most used. Even those of us who get after it as much as possible will probably have to drive across states from time to time. And there, youll put on 1,000 miles in the blink of an eye.

　　I have loved these tires on the highway. They are incredibly quiet thanks to the tires Whisper Grooves made to reduce road noise, and they handle more or less like an all-season tire. They havent affected the performance of my truck much other than one big factor: mileage.

　　To be clear, when I switched to the Discoverer, I also upsized from 31-inch tires to 33-inch tires. So the extra size adds a fair bit of weight and radius to the tire, which alone probably hurts my efficiency.

　　But frankly, this is a burly, heavy tire. Im running size LT275/70R18, and they weigh a hefty 57 pounds each. That means every time I mash on the gas, I have to spin up 228 pounds of rubber to speed. No wonder Im lucky to see 15 mpg. And its also no wonder that I drive a beater Toyota Corolla to work instead of my truck.

　　But for the vehicle that I use mostly for recreation, its a sacrifice Im willing to make. Cooper designed these tires to be extremely rugged and warranties them for 60,000 miles. So far, so good.

　　Cooper Tires: Great on My Truck

　　These tires get us where we need to go! The only thing I havent done is towed with these. So I cant speak to their performance for towing, although Cooper claims this to be a strong point.

　　Its worth noting that the few negative reviews Ive seen on these tires claim theyre hard to balance. I had mine mounted at Les Schwab Tires in Denver, and they had no problem.After about 10,000 miles, I really like these tires. They have a pretty rugged appearance, perform well, and I think also look good on my truck.

　　If youre in the market, they have a 4.5/5-star rating on Coopers website. I would personally give these five stars so far, with the only possible ding being on fuel efficiency. But for an all-terrain tire that tackles everything I need my truck to do, Im very happy with the Discoverer AT3 XLT.

　　Update! Cooper Tires Discoverer AT3 XLT Long-Term Review

　　At 50,000 miles, the Cooper AT3 XLT tires still have substantial tread; (photo/Sean McCoy) Well, here we are, more than 4 years since I initially wrote the above review of the Discoverer AT3 XLT tires. And after rereading it, I still stand by every word that I wrote. Ive driven them about 50,000 miles on roads and trails, in cities and the country, and I think they are fantastic tires.

　　Considering all the adventures these tires have taken me on, I get a little reminiscent. Theyve driven to South Dakota and back from Colorado a half dozen times, covering thousands of miles of highway and thousands more upon arrival over rutted-out gravel roads looking for pheasants.

　　After my dog cut herself badly on barbed wire, they rushed us 200 miles in a nasty downpour to an emergency vet. At the end of the day, everyone, including the dog, was OK.

　　Cooper Discover AT3 XLT tires with 50,000 miles; (photo/Sean McCoy) Theyve carried me safely through countless snowstorms to great ski days. Ive wrapped them in chains to scale insanely icy, rough, dangerous roads while elk hunting. They towed (yes, theyve done lots of towing now!) an Airstream trailer 400 miles across Colorado highways to a turkey hunting paradise.

　　As they near the end of their life (they have some tread left, but its time to move onto a new tire to test), Im amazed at their longevity, given the rough service theyve provided. I havent treated them all that well, only rotating every 15,000 miles or so. And yet, they are relatively even, showing only modest cupping on the inside edge of two tires that spent too long on the front wheels.

　　Pulled to the side of the road with a typical Colorado view; (photo/Sean McCoy) I could not ask for anything more from a tire. Theyve clawed over sharp rocks, rolled smoothly over dry highways, and only sprung one leak — when a nail found its way into the center of one tire. Theyre quiet, secure, durable, and long-lasting. I think these have at least another 10,000 miles of life left.

　　I only hope they find a good home for those last golden miles. Whoever straps them on for these last bits of life will enjoy one of the finest tires Ive ever used.

　　'Like a Lead Balloon' — When Your First Ultra Is the Leadville 100Can 'normal guy' Jeff Beecham overcome personal tragedy to complete his first-ever ultra — one of the world's toughest courses? Read more

　　Sean McCoy check price at amazon