Talk of Aston Martin returning to inline-6 engines dates back all the way to 2011, and despite official denials the rumors persist.

The latest rumors come from Autocar, which reported Friday that Aston Martin is developing its own inline-6, one potentially featuring hybrid technology, to eventually replace the current V-8 engine the company sources from Mercedes-AMG.

The report cited an anonymous source.

Aston Martin CEO Andy Palmer in September revealed that the company planned a turbocharged V-6 with hybrid technology for the code-named 003 hypercar due in 2021. He said the engine would be related to the current 5.2-liter twin-turbocharged V-12 Aston Martin offers.

It's unlikely two 6-cylinder engines, an inline-6 and a V-6, are being developed at Aston Martin, so perhaps something's been lost in translation.

Downsizing to a smaller engine is said to be seen as necessary for Aston Martin in order to meet stricter emissions regulations that will come into play should the automaker cross the 10,000-unit annual sales threshold. It's a problem that also afflicts Ferrari which is expected to cross the threshold with the arrival of the Purosangue SUV early next decade, which is why the Italian firm also plans a V-6.

Aston Martin has offered cars with 6-cylinder engines in the past. The last was the DB7 which offered a 3.2-liter inline-6. Aston Martin dropped the option in 1998.