Since rocketing on to the world stage 18 months ago, the McLaren 720S has established itself as one of the fastest road-legal supercars on the market.

Despite how fast it is, though, it isn’t the British marque’s fastest vehicle. Instead, that title is held by the McLaren Senna. So, just how much faster than the already insane 720S is the Senna? Autocar decided to find out.

In a series of videos, the publication will pit the duo together for a host of tests to determine just how significant the performance difference is. This first shows the duo going head to head in a 0-100-0 mph (0-160-0 km/h) race for the ultimate test of acceleration and braking.

During these tests, the 720S was able to launch to 60 mph (96 km/h) in 2.98 seconds and 100 mph (160 km/h) in 5.53 seconds. It was then able to screech to a halt just over 4 seconds later to finish with a time of 9.67 seconds.

As for the Senna, it actually took a little longer to reach 60 mph, hitting the mark in 3.14 seconds despite its additional power and lower weight. However, it did manage to reach 100 mph a little faster, in just 5.40 seconds. Thanks to its huge brakes, it also came to a stop a little quicker, completing the challenge in 9.17 seconds.

In the real world, it’s debatable if this half-a-second difference would even be noticeable. And one question that we’re left thinking about is how exactly McLaren is going to make an LT version of the 720 that doesn’t outperform the Senna.