He's definitely the coolest grandpa ever.

The Volkswagen Golf R is hardly what you'd call slow, but imagine doubling the amount of power it produces.

Well, a 75-year-old man in the UK has done just that. His Mk7 Golf R has been tuned to deliver just under 600bhp (447kW), not that you'd be able to tell by looking at it.

The main changes contributing to the power bump are a massive turbocharger and upgraded fuel pump he's "shoehorned" into the engine bay. You can get the full rundown of the modifications during the video clip below.

Watch for the presenter's face when he first experiences the Golf's acceleration, too.