There are several ways to determine which ATV is the biggest on the market, depending on which property you consider the most important. For some, having the most horsepower or torque is what matters, while others care more about vehicle weight or physical dimensions for heavy utility work.

The biggest commercially available ATV is the Russian-made Phantom amphibious ATV. This beast of a four-wheeler is 118 inches long, 67 inches wide, inches tall, features a 110hp 1.5l Toyota engine, and weighs in at 700kg fully equipped. And that’s just the Basic version. They also offer a Pro version and an Extreme version that are even bigger.

biggest atv Phantom
The massive Phantom may be the perfect vehicle to conquer the great Russian wilderness.

These massive off-road vehicles offer performance like no other ATVs only can. Don’t you believe me? You can see it in action here:

While the Phantom takes the victory in just about every aspect of being the biggest ATV, it is likely a bit too big for the average rider. Even those that merely want to have the biggest ATV in their riding group will probably go for something a bit more moderate.

That’s why the rest of this post primarily focuses on the biggest models within the most readily available and top-selling ATV brands.

If you want to learn more about the Phantom, please visit them at their website.

Among the top-selling brands, here are the biggest stock ATVs, ranked by key properties:

Ranking FactorThe Biggest ATV
Physical dimensions (length, width, height)Can-Am Outlander Max 6×6 XT1000
Engine size in horsepowerCan-Am Outlander 1000R series
Engine size in TorqueN/N*
Engine size in ccCan-Am Outlander 1000R series
Vehicle weightCan-Am Outlander Max 6×6 XT1000
Ground clearancePolaris Sportsman XP850/1000 High Lifter Edition
The biggest readily available stock ATVs, by key ranking parameters. *Data not available.

What Is the Biggest ATV Ranked by Dimensions?

The biggest stock ATV ranked by physical dimensions such as length, width, and height is the OUTLANDER MAX 6X6 XT 1000 with its L x W x H: 124.8 x 48.5 x 55.3 in. (317 x 123 x 140 cm).

Yes, it’s a 6×6, but it is considered an ATV regardless. The additional rear axle adds more than 23 inches to its length when compared to its four-wheeled counterparts and thereby making it to the top of our list. 

If we disregard 6×6 models for a moment and only look at conventional four-wheeled ATVs, there is no way around the Can-Am Outlander X MR 1000R. With its 97 inches, it’s not only the longest but with a width of 50 inches, no one’s wider as well. 

However, the X MR is not the only 50 inches wide ATV. Most manufacturers offer models that are up to 50 inches wide. Check this post to learn why no major brand offer ATVs wider than 50 inches. 

The tallest ATV is the Can-AM OUTLANDER MAX LIMITED with its 53 inches. Be aware it does not achieve this height due to massive wheels or tall suspension but rather a tall backrest from it being a 2-up model. 

What Is the Most Powerful ATV?

Two major brands are constantly battling to offer the most powerful ATV with the most horsepower; Polaris and Can-Am. For 2022, Can-Am takes the win with its 91hp 1000R engine. The engine is offered in various trims of the Outlander series, such as the Outlander XT-P, X XC, and XM R.

We find the Sportsman XP 1000 with its 90hp engine on a close second. 

In all practical terms, both ATVs are equally powerful. If one were to win a race over the other, it’s likely due to things like vehicle weight, clutch efficiency, wheels, and suspension.

Related: How Fast Can ATVs Go? (Different CC Engines Compared)

The Biggest ATV Ranked by Engine Size in CC

Some live by the saying, “There is no replacement for displacement. For those, it is good to know that the Can-Am Outlander 1000R series offers a 976cc engine, effectively making it the biggest ATV ranked by engine displacement. 

Once again, Polaris must settle for a second-place with its 952cc Sportsman XP 1000. In practical terms, this small difference is negligible tho. Other factors such as gearing, clutch design, and so on play a larger role in perceived engine performance. 

What ATV Has the Most Torque?

None of the major ATV manufacturers currently provide data on how much torque their engines put out, but the 2016 Polaris Sportsman XP1000 has 69 foot-pounds or 93.6 nM of torque. The Can-Am Outlander 1000R engines should be in the same ballpark. 

Some believe a bigger piston (bore) equals more torque, but that is not always the case. A longer stroke and/or cam port timing are just as important when it comes to torque. 

Each manufacturer designs its engines differently, and there is no way of knowing which one offers the most torque without running them on a dyno. 

Which Is the Heaviest ATV?

Due to the additional rear axle, the OUTLANDER MAX 6X6 XT 1000 with its 1170 lb (531 kg) takes the win once again. 

Among the 4×4 ATVs, the Can-Am X MR 1000R is the heaviest, weighing 1,014 lb (460 kg). What makes this specific model heavier than more basic 1000cc Can-Ams are the large mud tires, beefed-up suspension, and radiator relocation kit. 

In fact, the x MR 1000R is even heavier despite the longer wheelbase of the 2-up Can-Am Outlander Max Limited, weighing “only” 900 lb (408 kg). 

Which ATV Has the Most Ground Clearance?

Sufficient ground clearance is essential for not getting stuck on obstacles such as logs, stumps, and rocks when going off-road. It also helps prevent getting high sides when riding in deep snow or mud. 

The Polaris Sportsman XP1000 High Lifter Edition offers a ground clearance of 

13.5 in (34.3 cm), effectively making it the stock ATV with the highest ground clearance on the market. 

To achieve this much clearance, the High Lifter comes with features such as factory-installed 29.5″ High Lifter Outlaw 2 Tires, high clearance arched dual a-arm suspension, and stiffer springs for high ground clearance.

What Is the Biggest ATV in the World (Modified)

While some prefer keeping their ATVs mostly stock, others go all out with extreme modifications to make their ATVs bigger. This is done mainly to be able to go through bottomless mud pits where stock ATVs wouldn’t stand a chance. Others do it simply because of looks.

The biggest modified ATV in the world, as far as I know, is this Can-Am Outlander built by Gorilla Axles, offering a massive 3ft of ground clearance. This lift is made possible by an outrageous custom-made suspension that’s primarily meant for shows:

The biggest ATV with OEM style suspension I was able to track down is this heavily modified Can-Am Outlander, made by Performance ATV, located in Orange, TX:

Here is some key info behind this build:

  • Ground clerance: 36-38 inches, depending on how the shocks are set up
  • 6 inch P-ATV lift kit
  • Ccustom 8 inch portal boxes
  • 50 inch tire, cut by Racing in the dirt
  • Diff from Halo PerformanceHalo
  • Front driveshaft and Nitro axles by Turner DriveShafts & Steerings
  • Clutches tuned by P-ATV
  • C-fab rear diff confersion kit (modified)
  • Custom driveshaft

Please be aware that extreme builds like these, impressive as they are, may not be for everyone. They do come with a fair share of downsides, effectively making them useless for just about anything but the occasional pull through the mud pit. They are top-heavy, slow, expensive to build and maintain and wear fast. Expect to stock up on CV joints and axles, as you will most certainly need them.

What Is the Fastest Stock ATV?

ATV manufacturers do not advertise the top speed of their vehicles, as ATVs by design are not suitable for high-speed riding applications.

Some time ago, I wrote a post on how fast various ATVs go. I scavenged the web to learn what top speed various ATV owners have achieved on their bikes. While writing that post, I learned that the Polaris Sportsman 850 is the fastest stock ATV with a recorded top speed of 83mph (134km/h).

It is not clear why the 850cc Scrambler came out faster than the 1000cc model, but it may very well be due to incorrect speedo reading, or the 850cc may have been geared slightly faster than the 1000cc.

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I'm an ATV and offroad-enthusiast, an engineer, a farmer, and an avid home-mechanic. I'm also the owner and editor of BoostATV.com. If you have any questions or suggestions regarding this article, please feel free to contact me.