Tyres are vital to how a vehicle performs. That’s a tremendous understatement, but it’s worth repeating over and over because tyre choice often doesn’t get the scrutiny it deserves. We’re not just talking about opting for generic all-season tyres in winter, either. Tyre choice is critical in all conditions for getting power to the ground, but beyond that, mixing different brands and types is not only illegal in some countries but can create a dangerous, unexpected imbalance in grip.

This video from Tyre Reviews on YouTube showcases just that scenario. The test car is a BMW M2, sending 405-bhp to the rear tyres on a wet track as that’s a condition where tyre choice is both extremely critical, and most-often taken for granted. The test simulates a real-world situation where a throttle-happy driver might wear the rears out long before the fronts need replacing. It’s tempting to go with a cheap off-brand pair of new tyres as opposed to the original equipment, which in this case is represented by a set of high-end Michelins. As the video shows, doing that is a bad idea for several reasons.

Gallery: Premium versus budget tyre test

For starters, mixing any tyre brands will often result in a noticeable change in vehicle grip simply because they’re different. Tyre compounds, sidewall stiffness, tread pattern, these things all factor into a tyre’s performance and if all four don’t match, things can be unsettling. As it stands, this video shows minor differences in wet lap times even with mixing high-end tyres from different companies.

The real eye-opener, however, comes from installing a set of new budget-priced tyres on the rear. Details on the exact brand and type of tyre aren’t revealed, so, unfortunately, there’s no way to verify if this cheap pair is at least a high-performance design. Ultimately, it doesn’t matter because the Bimmer oversteers with reckless abandon during both a timed lap, and during a casual drive at normal speeds. Sure, you can switch the low-grade tyres to the front, but as the host of this video points out, the only benefit is that you’ll be able to see what you’re about to hit as opposed to spinning backward into it. Swapping tyre locations only swaps rampant oversteer for rampant understeer.

The next time you’re tempted with an inexpensive pair of replacement tyres, keep this video in mind.