Jeep doesn't consider Tesla's Model X a rival.

Jeep raised eyebrows when it introduced the Grand Cherokee Trackhawk, a 707-horsepower tire-slaying brute capable of hitting 60 mph from a standstill in just 3.5 seconds. While the company boasts it has built the world's fastest SUV, critics argue the segment's performance crown still goes to the Tesla Model X.

The X takes only 2.9 seconds to perform the benchmark zero-to-60 sprint, so it's over half a second faster than the Trackhawk. However, Jeep explains it doesn't consider the X a true rival.

"We use the 2016 Ward's UV segmentation data that classifies Jeep Grand Cherokee as a Middle SUV (Sport Utility Vehicle), while the Tesla X is a Middle Luxury CUV (Cross Utility Vehicle)," explained the company in a statement sent to Australian website Motoring.

The definition of the term SUV is subjective and, in recent years, as flexible as an old garden hose. The Model X ticks all three boxes: sport, utility, and, of course, vehicle.

However, most auto-makers and consumers argue off-road prowess and a certain degree of ruggedness differentiate SUVs and crossovers. The X is fast, spacious, and versatile, but there's nothing rugged about it.

When viewed from that angle, the Grand Cherokee Trackhawk is the fastest SUV on the planet, while the Model X remains the fastest crossover -- and one of the fastest production cars regardless of segment.

Tesla considers the Model X a SUV, and the company hasn't responded to Jeep's claim.