Fuel and lubricants were central to that development step. But how central will the role of PETRONAS be in finding yet more performance from the Power Unit?
"The rate of development from the Power Unit over the past two years has been very impressive," Andy continues. "Many people thought that there was not much opportunity to move things forward - but that has not been the case. There have been significant new advances - and fuel and lubricants have been one of the main focus areas. Our 2015 mid-season update incorporated a sizeable step in fuel performance from PETRONAS. Then, later on in the year, we also introduced a new lubricant. We've made further progress in the way we've designed the combustion system and also enhanced the properties of the lubricants to reduce friction in the engine. PETRONAS are a key partner for us. They're not just branding on the car - but a deep-rooted technology partnership. Anybody who designs engines knows that good fuel and lubricants are key to performance - and we're very fortunate to have such a close and productive working relationship with PETRONAS."
Noise has been a hot topic since the new Power Unit formula was introduced in 2014. But what's changing in 2016 to pump up the volume and will this have any effect on performance?
"We've been conscious since the start of the Hybrid era in 2014 that the volume has diminished for those up in the grandstands as well as those watching at home," says Andy. "This is down to both the nature of a turbocharged engine and the recycling of waste energy in the exhaust system. The FIA therefore undertook an interesting and thorough investigation to analyse noise in the tailpipe and investigate what could be done to increase noise without impacting performance or efficiency. What they spotted is that the waste gate fed into the tailpipe. So, when the waste gate is not open, it's a dead end. It then becomes a side branch resonator - or effectively a silencer - on the tailpipe. That design has now been removed, so we are left with a nice clean pipe without any silencing points, which should improve the noise of the Power Unit."