when i was in the trade, the fastest MK1/2 Golf GTi's we got in had been driven hard from new, but also serviced properly.(i drove about 3000 of them in 9 years) the engine builder for my MK1 and MK2 Golf GTi said if you don't drive hard, the engine won't bed in and the bores glaze up meaning the oil consumption stays high. i bought a Jetta GTi 8V with 100,000 miles on it, but it was very slow and down on power because it had been driven on a light throttle all its 1 owner life. by the time i sold it at 150,000 miles, it did a 16.1 1/4mile at Santa Pod with the weight of a full cage in it, and put down 135bhp. i had the head worked on and other stuff like 4 branch, but the block/crank/pistons were still untouched. my current Cupra has been thrashed from day 1, day 2 was a 120mph trip to get the exhaust changed, but it has had 2 oil changes so far as well! ( 1 at day 3, and 1 at 1800 miles). so far, goes like a rocket and uses no oil. running in was advised for cars years ago when parts could not be machined with todays tolerances and had to be 'introduced' to each other carefully. race engines had to be 'blueprinted' to avoid seizing, that is, rebuild exactly with the correct clearances etc as factory. so, a new car does not need 'running in', it needs using as intended.
