It FELT hotter. 'Feeling' the temperature of 'the engine bay' is not a reliable way of telling if the engine is having problems. Maybe it was more humid at the time you felt that it was hotter? Maybe you just had your air-con working harder? Maybe it's your cooling system? If the temp needle doesn't go beyond the safe level, whatever increase in temperature you feel from the engine bay is most of the time irrelevant. If it does indeed get hot, I wouldn't blame the fuel either. It's not like you're running the car with a mixture of nitrous oxide and methanol.