I’ve posted a few times before about the trend for automakers to upsize engines for the sake of improving real-world fuel economy and emissions performance. This time, I thought I’d build a timeline of manufacturer statements that they’re increasing engine sizes for these reasons, or (really, this is mostly Mazda and to an extent Toyota) avoided the trend altogether for those reasons.

Right now, this is pretty bare, but it’s meant as a work in progress - I’ll add things as I find them. Feel free to suggest other entries, I’ll add them.

2017-02-03: The age of engine downsizing is over, says Volkswagen (1.0 l 3-cylinders will continue for up! and Polo, no development of smaller engines than that, no development of smaller diesels than 1.6 l)

2017-01-24: New 1.5 l petrol engine for the Yaris (Real Driving Emissions and Euro 6c explicitly cited as the reason, 1.5 l NA with wide-authority VVT and limited Atkinson-cycle operation replacing 1.3 l NA for the European market)

2016-10-14: Carmakers forced back to bigger engines in new emissions era (Renault going from 0.9 l turbo to something larger (likely ~1.2 l), 1.6 l turbodiesel to ~1.7 l turbodiesel, GM going from 1.2 l turbodiesel to ~1.5-1.6 l turbodiesel, VW going from 1.4 l turbodiesel to 1.6 l turbodiesel)


2016-04-28: Volkswagen’s new engine packs a variable geometry turbo (1.5 l turbo Atkinson-cycle engine replacing 1.4 l turbo Otto-cycle engine - while the displacement increase isn’t explicitly stated to improve efficiency, it was likely necessary for the Atkinsonization that Volkswagen did, and that improved efficiency - also, due to that and other technologies added to the engine, they’re claiming that the benefits apply in the real world)

2013-10-10: Toyota lays out future powertrain plans in catch-up bid (Atkinsonizing and upsizing suggested as the way to go for future Toyota powertrains to improve power and efficiency - however, Saga in a 2014 interview with the same outlet suggests going with downsizing and turbocharging anyway)


2013-06-03: Technology Breakthrough by Operation Breakthrough (last slide of this PDF mentioned that Mazda maintained displacement in the SkyActiv-G family from the previous Z and L families due to real-world efficiency benefits)

2009-03-02: All-New Third Generation Toyota Prius Raises the Bar for Hybrid Vehicles - Again (1.8 l NA Atkinson-cycle replacing a 1.5 l NA Atkinson-cycle engine, claims of improved highway fuel economy due to lower RPM operation)