Evening mate, people are asking if you us the correct octane fuel i.e 98 plus...When you open your petrol flap it tells you to use 98 ron. Your normal fuel of the pump is 95 unless your using V-Power, Excellium etc etc which are 97,98 or 99....You should use one of the latter really.
I think heat soak is the temp of the engine etc, if you drove on the motorway doing 100mph it would be getting rammed with a 100mph air flow. Some rolling road dont use fans when testing the cars hense mega heat, they should have placed a large fan infront of the car and lifted the bonnet, well all the ones ive been to have lol.
Like anything mechanical is should be maintained and serviced right...Better serviced engines should perform better...When was the car last serviced.
Hope this helps.