The electrified powertrain will eventually become the new norm for passenger cars, but the majority of those vehicles will continue to utilise an internal combustion engine (ICE) in some form until 2030 at the very least. As such, further optimisation of the ICE will be essential to the future of sustainable mobility.
Automakers must comply with tightening emissions regulations, but sales of battery electric vehicles (BEVs) have not picked up as expected. Globally, the market share of BEVs remains in low single figures compared to diesel and gasoline passenger cars, but hybrid architectures could prove a more palatable option. As a result, the ICE is expected to remain in focus for years, if not decades to come.
According to powertrain development and testing specialist AVL, automakers must consider a ‘modular approach’ for their global powertrain line-up. “A modular engine family architecture that allows automakers to integrate different technology packages can enable an affordable line-up of powertrains,” explained Wolfgang Schoeffmann, Head of Base Powertrain Technology at AVL, during a recent Automotive World webinar.
A modular powertrain can be leveraged across a range of applications, and rather than adding an electric motor here or there, a number of tweaks can be made to the ICE itself for fuel efficiency gains.
A hybrid world
A similar trend can be seen elsewhere in the vehicle, with a general push to increase the level of commonality between individual components, systems and platforms. The idea is to have a foundation on which numerous models and powertrain variants can be built, cutting development costs and improving the level of global scalability. It is an important consideration, as the death of the ICE is not due any time soon.
It is a challenging reality for automakers, which are faced with pouring investment into electrified powertrain R&D at the same time. Back in October 2018, ministers from the EU 28 approved plans to cut light vehicle CO2 emissions by 35% by 2030. “Optimisation of the combustion engine alone will not be sufficient,” admitted Schoeffmann. Based on AVL research, he anticipates the following powertrain mix to materialise by 2030: hydrogen fuel cell vehicles (FCVs) will account for just 2% of the light vehicle market in the European Union; full hybrids 13%; BEVs 22%; plug-in hybrids (PHEVs) 24%; and taking the majority share (39%) will be 48-volt mild hybrids. Pure ICEs without any electrification will have been wiped out, he believes.
Looking at the bigger picture, that grouping of hybrid vehicles—which would account for more than 75% of the total mix under this forecast—will still use a combustion engine. It not only highlights the importance of investing in electrified powertrains, but also the ICE, argued Schoeffmann.
“An increasing number of powertrain architectures with partially complex hybrid solutions are required to cope with stringent fuel consumption and emission legislation,” he said. “There is also clear competition arising between a range of different technologies.” For example, automakers will need to pick and choose from solutions such as variable compression ratio, variable valve lift, advanced boosting technologies, high-pressure injection and water injection. “These all require significantly increased efforts in terms of both development and investment,” advised Schoeffmann.
Is it worth it?
Mild hybridisation shows particular promise, often providing many of the benefits associated with a plug-in variant. “48-volt hybrids already offer considerable reductions in fuel consumption throughout all vehicle segments,” noted Schoeffmann.
The investment required to develop and launch electrified powertrain technologies, many of which remain in their infancy today, is substantial. Some have questioned whether investment in the ICE alongside new ventures into e-mobility is even feasible. However, Schoeffmann believes it is non-negotiable.
“People ask whether it is worth investing in the ICE if you need to move toward electrification anyway—why not just use a very cheap combustion engine? But we have found that hitting the fuel efficiency sweet spots in an ICE is absolutely essential, and particularly for PHEVs.”
Indeed, most PHEVs have a real-world electric driving range of between 25 and 30 miles (40-48km) today. If the battery runs flat during a long drive, the onus rests on the ICE for the rest of the journey. The effect on fuel efficiency is night and day—sometimes dipping from around 100mpg to below 30mpg in some models. “We want to avoid this annoying disparity in fuel consumption,” Schoeffmann concluded.
Click here to see a replay of the full webinar.
