Audi RS3 vs Mercedes A45 S: the drag race in numbers

Little bit of a battle royale here, as the Audi RS3 takes on the Merc-AMG A45 S. We ran the twin test back the other side of Christmas, but we know you like a stat so here’s how they fared head-to-head in a drag race.

The Audi won. Not by much, but consistently. And this despite the Merc being a) lighter and b) more powerful. So what’s going on?

First of all, here are the numbers:

Now, we should point out that the track we were on was fractionally damp with dew and perishingly cold – daily ambient was about five degrees. The Audi wore winter tyres, the Merc summers. On a dry spring day I’d expect both to go a tenth or two quicker – indeed I’ve previously tested an A45 S that put in 60 and 100mph times of 3.7 and 8.7secs. But this is what happened on the day.

Back to why the RS3 pulled out an advantage despite having a power-to-weight ratio of 251bhp/tonne against the A45 S’s 267bhp/tonne. Both have identical 369lb ft torque figures, but the Audi’s peaks much lower down. All that twist is available from 2,250rpm, whereas in the Merc you don’t have it until 5,000rpm. Since launch control in both dials in at around 4,000rpm, and wheelspin isn’t really a thing, the five-cylinder Audi hooks and goes with a hint more vigour.

Merc tuned the A45’s power band on purpose to give you a reason to hold on for high revs – and it works: it’s a freer revving, more exciting and responsive unit and in isolation feels blisteringly quick, but the RS3 just thumps off the line that bit harder. At 30mph it was a tenth ahead, by 50mph that had grown to two-tenths and there it sat.

We filmed it and the RS3 simply pulled out about a car’s length and then the A45 pegged it. From then on they were fabulously even. From 60-100mph there was just 0.08secs in it. The advantage there lay with the Merc, which did feel as if it was fractionally inching back into contention, but that you’d need an autobahn for it to get the three-pointed star in front of the four rings.

But there’s something else. When the Audi shifts from first to second I think the engineers have done something clever with the DSG’s clutch engagement, because it seems to surge as second engages. Enough to give it an additional kick up the road. The Merc just delivers clean, instant shifts.

By the way, our results reflect each firm’s claims. Audi says 3.8secs for the 0-62mph, Merc 3.9secs.

However, this RS3 is no quicker than the last (which we timed at 3.74/8.98secs for the 60/100mph barriers). And that was only a little quicker than the one before back in 2011 (3.8/9.9secs). And don’t forget Audi hasn’t chosen to chase Merc beyond the 400bhp barrier. So is it possible that, finally, the hot hatch power wars have plateaued? Well, until EV AMGs and RSs land of course.