Hi guys, i bought my Peugeot RCZ 1.6 156hp 2013 plate, just a few months ago. So far i have used total quarts INEO FIRST 0w/40 - as recommended by Halfords. Just wondered if its better to use a thicker oil as the car is old now and 70k miles on the clock. Car is running smooth regardless but just wanted to double check for longevity reasons. Any help would be appreciated cheers!