There’s a video going around the internet at the moment, showing an RS5 Sportback lapping Magny-Cours slower than an M3 Competition Package. Before we watched the video, we assumed the reason for its slower time was understeer, as it can often plague fast Audis. However, upon closer inspection, understeer is not the culprit, here.
Both cars are similarly powered, with similar engine types. The Audi RS5 Sportback uses a 2.9 liter twin-turbocharged V6 with 444 hp and 443 lb-ft of torque. While the BMW M3 Competition Package gets a 3.0 liter twin-turbo straight-six with 444 hp and 406 lb-ft of torque. Both also have automatic gearboxes (in this instance), but the Bimmer’s is a dual-clutch while the the Audi’s is a traditional torque-converter auto.
During these tests, both cars were driven on the same track, in similar conditions, at different times but by the same driver. Despite the M3 being a few years older, it recorded a 1:59.80, compared to the 1:59.97 for the Audi RS5 Sportback. That’s not a huge difference but it’s enough to hand the M3 the victory over the RS5.
In the video from inside the RS5’s cabin, we can see that it does struggle with a bit of understeer at the limit. However, that’s not what caused it to have a slightly slower time. Instead, it was the cars tires that did it.
According to Motorsport Magazine (who conducted this test and filmed this video), the Audi RS5 Sportback was severely under-tired compared to the M3. While the Bimmer used ultra-sticky Michelin Pilot Super Sport tires, the RS5 had to make do with Hankook Ventus S1 tires. The latter of which are not bad tires by any means, in fact I’ve come to really appreciate the Hankook brand. However, Michelin PSSs are ultra-high-performance summer tires and the Ventus S1s, while good, are high-performance all-season tires. Even the best all-season performance tires on the market would struggle to provide the same level of grip as a set of sticky Michelin PSSs.
In fact, we reckon that if the Audi RS5 Sportback had the same sticky tires as the M3, it would have been the faster car. With all-seasons,the RS5 was just over a tenth of a second slower than the Bimmer, so with better rubber it would have won the day. So while it’s impressive that the BMW M3 is still so good all these years later, it only won at Magny-Cours thanks to its Michelins.