Oil level / performance?!

Strange one, i checked my oil wednedsay night as i thought it might be a bit low, as expected, it was just under the hatching on the stick (engine was hot, just switched off) So i left it an hour, came back, dipped it, and it was 1/3 - 1/2 the way up, so i bought 2 litres, slapped just over a litre in it so im on the top of the hatchings (engine cold). I then went out in the car up to college and the misses house (college is around 3 miles and her house probably 10 miles) both on a long dual carrigeway, so there's pleanty of time to get the engine warm, then give it some stick in the higher gears for a turbo-size. Main point being, it seems more powerfull with the oil topped up Its just normal, castrol 10-40 for a diesel engine 505 spec, so nothing too special really. How come im feeling more power? Its definatly not just in my head, because i didnt expect more power just from oil!

Anyone any input, or has anyone else noticed it? Engine is a 110TDI ASV block. No mods other than CCV/EGR stuff.

Yeah, could of been running cooler, didnt think of that to be honest, but would just over a litre of oil be able to cool the engine so much? Ambient temp was up if anything, ive made the trips in much colder temps, it was near freezing this time last week, and it still performed better since ive topped the oil up.