Having won 63 of the 79 races held since the new engine formula was introduced in 2014 - that's 79.7% for all those FOM numbers men - it's fair to say that the German power unit is the benchmark.

However, never one to rest on its laurels, and aware that Ferrari, as well as Renault, will be seeking to make up ground this year, Mercedes is planning an all new unit for 2018 as it prepares to defend its titles for a fifth time.

"It's had several phase-ups through the season and we've got ideas to improve the power, the indicated power in the engine," Andy Cowell told Motorsport.com. "We've got ideas to reduce the friction in pretty much every area of the power unit, or the losses in electrical systems.

"Every time you do an engine, every time you do a phase update you've always learned," he continued. "So you freeze the concept, you do the work, you do the prove-out, you go racing and all the way along that journey it's intensely frustrating because you're learning but you cannot incorporate into that phase without corrupting the quality fundamentally.

"So it's ensuring that we do have a learning culture that observes and learns and reflects and then remembers that so that then when it's time to put the next concept together we've got a whole load of ideas and a lot of it is small, marginal gains on well-trodden areas.

"Some of it is big, fundamental bits of learning," he admits, "combustion progress, friction reduction, new materials that unlock areas where we've been struggling with reliability. And sometimes it's just a surprise.

"There's still gains to be had," he insists, no doubt striking fear into the hearts of his company's rivals. "It's a plethora of marginal gains, five millisecond gains. Then there's those nice surprises where you thought north would give you 2kW and actually it's south that gives you 2kW.

"It has just been about doing those great experiments and that's where the test facility is important. You need to think about what it is you're trying to measure but you need a very impressive dyno with incredible sensors and good test methodology to genuinely detect those gains and to pick them out from the noise of general testing."