Ah. I see where the confusion comes in, having just checked Google and the urban dictionary.
"Give it some thrutch" was a term used when I was A LOT younger to encourage a driver to press firmly on the accelerator, or otherwise to make the most of whatever power was available in the car being driven. Typically a Mk 1 Escort, HC Viva, Triumph 1300 or whatever early 70s car one's pals fathers had agreed to let one take out for the evening to meet one's mates.
One pal's dad was a manager with Natwest bank and had one of the first Audi 100's. Half a dozen 18-year-olds driving that round Liverpool city centre on a saturday night and not pulled up once. The same six were also often crammed in an 850 Mini. We never got the use of the Rover 3500 which another pal's dad owned though.
Geoff's on a nostalgia trip this evening.