The initial discussions between the FIA and the engine manufacturers were focused on delivering a more efficient internal combustion engine and more potent Hybrid systems. Both sides were keen to move the sport in this direction. With a normally aspirated engine, the power potential is controlled by the flow of air into the engine via the capacity and the rpm it can be run at. However, the automotive industry is focused not on air consumption but on fuel consumption—and the CO₂ emissions this generates. The sport has therefore turned the rules on their head with a formula where the performance is restricted by two fuel mechanisms: a maximum fuel flow rate of 100 kg/hr and a maximum race fuel allowance of 100 kg. The fundamental challenge is to convert as much of the chemical energy in the fuel, into mechanical energy, as efficiently as possible at the prescribed flow rate. Conversion efficiency is now the key.

—Andy Cowell Managing Director, Mercedes AMG High Performance Powertrains

The F1 W05. Click to enlarge.

Under the new F1 regulations, the engine has been formally replaced by the Power Unit, comprising six separate elements: the Internal Combustion Engine (ICE); Motor Generator Unit-Kinetic (MGU-K); Motor Generator Unit-Heat (MGU-H); the Energy Store (ES); the Turbocharger (TC); and Control Electronics (CE).

The performance specification of the Power Unit for the 2014 season must be homologated on 28 February. After this point, only modifications for cost and reliability reasons are permitted. 8% of the current Power Unit will remain homologated at the end of the season, with 92% development freedom for 2015.

Per the regulations, the Mercedes team downsized their internal combustion engine (ICE) to a 1.6 liter V6 configuration and down-speeded to a maximum of 15,000 rpm. To achieve high power delivery and therefore efficiency from the ICE, a pressure charging system has been introduced, in the form of a single stage turbocharger and compressor.

The new Hybrid Energy Recovery System (ERS), which incorporates electric motors capable of recovering both kinetic and waste heat energy, presented a ten-fold greater challenge than its predecessor, KERS, introduced by Mercedes-Benz in 2009.

Our learning during the KERS project was the bedrock for building ERS. But we are talking about a big step not just in absolute power but probably more significantly in terms of duty cycle, in other words the percentage of the time around a lap that it is operation. You could in theory combine two of last year’s KERS motors on a single shaft to achieve the maximum power of 120 kW. But instead of using the motor for just short of seven seconds per lap as we did last year, now it’s on for over 30 seconds of every lap. And there is also a much greater reliability requirement, because there are only five of these motors per driver per championship. So it’s more power, a harder duty cycle and significantly greater reliability demands. What’s more, it’s no longer something that’s ‘nice to have’ – given the power and the duty cycle, the car will be seconds slower without the MGU-K working, so you need it to do laps. Stitching all of that together with an absolute deadline is a big challenge, probably to an order of ten times more challenging. And that’s just one of the six parts of the Power Unit we are producing.

—Andy Cowell

Fluids. PETRONAS scientists developed a new fuel for the 2014 Power Unit, balancing characteristics such as energy density, octane number and volatility with careful consideration of the mandatory fraction of the fuel that must be of bio-origin.

This posed a challenge as some of the best components for delivering high, smooth power are also those that likely lead to deposit build-up in injector nozzles. An extensive development program involving chemists and engineers testing new fuels in real engines has resulted in a new generation fuel for the V6 that promises to deliver a significant gain in performance.

The smaller engine and increased power per liter mean that it runs hotter. Oil thins at higher temperatures; thus, a hotter engine needs a thicker oil to stop metal components from rubbing together and failing. However, the hotter conditions and reduced quantity of oil in the ICE (reduced from almost seven liters for the V8 to fewer than three liters for the V6) also mean that the oil must contribute more to cooling the engine. This requires thinner, faster flowing oil.

Additionally, the regulation changes restrict the quantity of fuel that can be consumed per race to 100 kg, which means that the oil needs to help conserve energy by minimizing friction. Again, this requires thinner oil.

In order to meet these complex and contradicting requirements, the new engine oil for the 2014 car is a precisely balanced mixture of advanced, thinner synthetic base oils to help cooling and polymer viscosity boosters (which kick-in at higher temperatures) to thicken the oil. Friction-reducing oil components, which make it easier for metal surfaces to slide past each other, have also been used to improve overall fuel economy.

Another consideration is that the higher temperatures also make it more likely that the oil itself will stop working properly. High performance additives have been included to stop the oil from breaking down under these extreme conditions.

Energy losses in the gearbox can also have a significant impact on fuel economy. To address this, PETRONAS technologists have also produced precision gearbox lubricants for the 2014 car to ensure that energy losses in the transmission are kept to a minimum, while making sure that the gearbox is protected from failure.