1.4L is the *magic* number for 2016 engines

[gone-ot]

From the SAE website: The 1.4-liter solution for 2016 fuel economy - SAE International

[Frank Lee]

I want more sub-one liter choices.

[gone-ot]

Originally Posted by Frank Lee

I want more sub-one liter choices.

I agree 100%!

[Baltothewolf]

The time of 1L gas engines have come to an end. With all the safety regulations on cars now, they are just to heavy to get good FE with 1L gas engines. Now, how about 1L diesel! They still have enough torque to push heavier cars and still get good FE!

[niky]

Turbo 1.0s work very well on compact and subcompact cars. Plus they help you clear more space for crash structure.

Ford uses them on the Fiesta, Focus and the Ecosport.

MINI now uses them in place of the old naturally aspirated 1.6 in the hatchback.

Never had much love for naturally aspirated 1.4s... The economy (usually) of a 1.6 mated to the power of a 1.3. Your typical lose-lose situation.

[gone-ot]

The formula for the future:

Turbo + direct gasoline injection + smaller CID + appropriate gearing = more HP & better MPG

[serialk11r]

Honestly I am not so sure that turbo is *the* solution. Toyota seems to be fighting every single new feature in engines, including DI, turbo, and variable lift. Their new crop of engines is going to use the same variable cam phasing with a bigger range and faster actuation plus plain old port injection, and they say these engines are going to have class leading efficiency.

Displacement is cheap, and most engines are not near maxed out in the displacement department. GM's small block engine with its 7L capacity and unrivalled power density is a reminder of that fact. I would say Toyota is being smart with their increase displacement, add EGR, increase compression ratio, allow valve timing tweaks strategy.

Honda has a slightly different approach with their 3 stage VTEC, which is even better for producing high power density, but they are willing to bite the bullet and throw in direct injection as standard. I think the Earthdreams K24 is still the usual 2 stage VTEC but the J35 Earthdreams is doing very well in the mpg department thanks to the 3 stage VTEC.

If you think about it, the reason why these turbo engines look like they're much more efficient is because there's a much wider range under which the throttle is nearly wide open and the throttling is being controlled at the turbine's wastegate and recirculation valve. Fortunately, a turbo is able to collect a decent amount of waste energy from the exhaust so wasting this energy is not a big deal. An electrically assisted turbo would make good use of this and further increase efficiency under full load.

However the underlying engine still has a lot of room for improvement. Using a high compression ratio and an Atkinson cycle mode, you can expand the high BSFC range by a lot, and better yet, improve the peak efficiency considerably.

Bang for the buck wise, it's easier to add these small improvements to the underlying engine than to downsize and then add power back with a turbo.