This shocking video shows the effect of mixing tyres on a BMW M2, which experiences catastrophic oversteer as the throttle is lifted when budget tyres are fitted on the rear.
Your choice of tyres is critical, no matter what weather conditions, as they are responsible for putting the engine’s power on the ground. Mixing different brands and types is not recommended – indeed It is illegal in some countries – as it can create a dangerous imbalance in grip quality.
This video from YouTube showcases the worst-case scenario, where the test car - a BMW M2, which sends 405-bhp to the rear tyres – is run a wet test track. It simulates a real-world situation of a throttle-happy driver who has worn out the rear tyres well before the fronts need to be replaced. In such cases, it can be tempting to fit cheap tyres.
Why is this a bad idea? Well, mixing tyre brands can result in a noticeable change in grip. Tyre compounds, tread pattern and sidewall stiffness all factor into your tyres’ performance and if the four do not match, the car can become unbalanced.
The real risk comes when a set of new budget-priced tyres are fitted to the rear. The specific brand and tyre type are not revealed, so there’s no way to verify what type of tyres are used, but the car oversteers wildly. This does not just happen during a timed lap, but also during a casual drive at normal road speeds.
It’s not sufficient to fit the cheap tyres to the front instead: that just means you will be able to see what you are about to run into instead of spinning into it backwards. Swapping the cheap tyres to the front would just swap oversteer for understeer.
So, the next time you’re tempted to fit cheaper replacement tyres, keep this risk in mind.