New Audi RS 5 Avant PHEV Spied, Will Challenge Mercedes-AMG C 63 With Two More Cylinders

BMW isn't done with the fabulous twin-turbo I6 of the M3, and neither is Audi with its twin-turbo V6. The 2.9-liter engine will return to the RS 4 for the B10 generation, but similar to AMG, it will be assisted by an electric drive unit. Our spy photographers captured a camouflaged prototype of the next-gen RS 4 Avant back in January 2024, sporting massive flares and – obviously enough for a PHEV – a charging port door on the left side.

Two months later, two RS 4s have been spotted testing in Sweden rather than Germany. Before going any further, it should be mentioned that we're actually looking at the RS 5 Avant because Audi really likes to confuse everyone. The TL;DR take is odd numbers for combustion-engined vehicles and even numbers for electric vehicles (think Q4 e-tron and the upcoming Q6 e-tron).

This, in turn, means that the B9-generation A4 series will become A5 for the B10 generation. That's not all, though, because Audi won't abandon its A4 trademark. Expected in late 2025, the A4 e-tron will follow in the footsteps of the A6 e-tron on the PPE platform of the Q6 e-tron and Porsche Macan.

Right, where were we? Unlike the A5 and S5, the RS 5 is believed to drop in the first part of 2025 at the earliest. It's not known whether Audi Sport will offer a liftback sedan or not, a decision that would open the RS 5 to a wider audience. In addition to four-door sedans, both AMG and M offer station wagon-bodied versions of the C 63 and M3.

A wider track and what appears to be a full-width light bar outback help the B10-generation Audi RS 5 Avant stand out from the RS 4 Avant. Pictured on two distinct wheel designs, the go-faster wagon should get matrix LED headlights and digital OLED lighting tech out back. Don't ask how much it would cost to replace a single cluster in case of a failure because everyone knows the answer is "a lot."

The plug-in side of the powertrain also means a higher starting price. With the RS 4 Avant currently going for 87,500 euros in Germany, the RS 5 Avant could be closer to 100,000 euros from the outset. As long as Audi doesn't mess up the interior design with too many piano black trim and touch controls instead of physical ones, that relatively high starting price would make a lot of sense over the internal combustion-only M3 Touring and 116,959.15-euro C 63 S E Performance T-Modell from AMG.

We're not bothering with conversions to freedom eagles because there are slim chances for the RS 5 Avant to be sold in the United States market. Considering the increasing popularity of crossovers and trucks in this part of the world, even a Sportback would struggle to justify its existence in the US market. There is, however, a glimmer of hope.

A little under a month ago, the all-new M5 Touring was confirmed to land in the United States. With BMW taking such a risk with the RS 6 Avant's rival, Audi should take note. The big question is, will the RS 5 Avant even come close to the C 63 S E Performance T-Modell in terms of max output? As a brief refresher, the most powerful C-Class from the 206 series produces a ridiculous 671 horsepower and 752 pound-feet (1,020 Nm).