After its 4-door sales soar, Porsche ponders a mid-size BMW 5 Series rival

2014 Porsche Panamera left motion

It may be best known for the 911, but Porsche is pretty good at building normal cars.

Since the launch of the Cayenne in 2003, the company has encroached on luxury-car territory previously dominated by fellow Germans BMW and Mercedes-Benz. Porsche recently launched the smaller Macan crossover to complement the Cayenne. So why not build a smaller sibling for the Panamera sedan?

According to Autocar, Porsche is planning exactly that, although the result won’t exactly be compact.

The magazine reports that Porsche wants to build a rival to the BMW 5 Series, the most established midsize sedan on the market and a car benchmarked by everything from the 2014 Maserati Ghibli to the Tesla Model S.

The primary motivation behind such a car would be increased sales; the 5 Series and similar-sized rivals like the Audi A6, Jaguar XF, and Mercedes-Benz E-Class are extremely popular.

However, Porsche boss Matthias Muller told Autocar that a 5 Series-fighter is just one of several possibilities for a less-expensive model that the company is considering.

If it does get built, the new model will reportedly use Volkswagen’s new MSB platform, which is designed for high-end rear- and all-wheel drive vehicles and will underpin the next Panamera and future Bentleys.

Porsche has carved a profitable niche making radically sporty cars for normally staid market segments. A midsize Porsche luxury sedan would probably blow most of its competition out of the water, save the Maserati and top performance versions of the rest of the class.

It will also bring Porsche further into the mainstream, and further anger traditionalist fans. That’s the price of progress, though.

Is a 5 Series-fighter one model too far for Porsche? Tell us in the comments.