I guess if governments continue to tighten emission standards, then the atmospheric engine could phase out altogether for small capacity turbos.
However, increasing emissions standards further again, could phase out all conventional ICE's for hybrids and upwards.
Increasing emissions standards again, could phase out hybrids in favor of plug-in hybrids.
Further increase in emissions standards again would phase out all ICE, hybrids and plug-ins for full blown EV's.
Interesting to note that it may not be that easy to replace the hybrid or small capacity turbo hybrid for plug-in hybrids, especially in sedans.
The first generation hybrids like the 2005-12 GS450h had tiny half sized trunks.
The second generation hybrids like the 2012-19 GS450h has a much more competitively sized trunk, while the current IS300h has its trunk reduced by only 30 L from 480 L to a still very useful 450 L metric. A standard C Class/3 Series has identical 480 L metric trunks. A Camry/GS has a 520 L trunk.
The third generation hybrids now are sandwiching the battery packs between the rear seat base and fuel tank, for zero loss of trunk capacity.
Theoretically, plug-ins have battery packs that are roughly
three times larger than hybrids. Hence more electrical energy, and bigger electric motors for much greater portion of power being delivered by EV, as opposed to traditional fossil fuel burning ICE.
Because the plug in's battery pack is roughly three times larger and heavier than the hybrid's battery pack, hence the
trunk volume of a BMW 330e falls to just 370 L metric, while the Mercedes C350e with an even bigger battery pack for more linear power - the trunk volume falls to just 330 L metric.
Worse, the C350e now weighs some 100 kg more than an IS300h, such that the
extra weight of plug-ins will surely affect handling.
Furthermore, because the plug-in battery pack is often located in the rear overhang, the spare tire compartment is gone, and the vehicle uses
run flats.
Thus,
plug-ins have their
pros and cons.
Because plug-ins have their pros & cons, there is certainly room for a Lexus twin turbo hybrid with a compact battery pack neatly sandwiched between the rear seat base and the fuel tank - esp for a sedan.
With tall wagon SUV's, the location of the big plug-in battery pack becomes much less of an issue.
Presently, there simply is NO perfect engine format.
Each format has its pros and cons.
1) Atmospheric with poor economy & emissions.
2) Turbo with poor response.
3) Atmospheric hybrids with reduced trunk capacity and extra weight over the rear overhang.
4) Turbo hybrids - ditto above.
5) Atmospheric plug-ins with
considerably reduced trunk volume, with considerable weight over the rear overhang, and run flats/tire repair kit eg Prius Prime.
6) Turbo plug-ins with
considerably reduced trunk volume, considerably more weight over the rear overhang, and run flats like 330e & C350e.
7) EV with a very very large & heavy battery pack.
Meanwhile, solid state battery EV's are a good 5-10 years away...
