This has been in the works for a few years.
 

https://global.nissannews.com/en/releases/210226-01-e

A strong hybrid with an engine optimized to run in one power band has always been one of my solutions of choice.

Basically what has been attempted on buses for a while, even in my country.

The ICE part begins at youtu.be/jeUEEfnr5-k?t=1149

It relies on promoting a swirl in the combustion chamber. The spark plugs would need to be clocked correctly.

Don't have time to pay attention to the video at the moment (funny they dub male speakers with female voices).

This appears to be a series hybrid. I'm always confused if the first gen Volt was a series hybrid or not, but I know the BMW i3 with ICE was. Makes all kinds of sense to me, especially if they incorporate ~16 kWh battery that can be plugged in for an initial all electric range of 60 miles.

I'll really get excited when these technologies reach the vehicles most in need of them; larger trucks, SUVs, and vans.

Interesting,

The Epower transmission peaks at about 80% efficient similar to an antique slush box.

By increasing engine efficiency they should be able to overcome the inherent inefficiency of a series hybrid

Nissan has teased the epower coming to the US for 5 years, see if it ever makes it.

Make mine a plug in Note when it comes over (doubtfull any epower ever will and if it does expect it in a landbarge)

Nissan has been selling an e-Power Note in Japan since 2016. This is the same powertrain with a step up in efficiency (if it works outside the lab)

My understanding is that although serial hybrids work well for low speed operation they aren't the most efficient way to transfer power at highway speeds. That is why the Prius, Volt, and pretty much every other hybrids is a series / parallel hybrid to allow the most efficient mode for the travel conditions.

Japan would have ideal conditions for a serial hybrid with their dense cities and low speed limits. (The highest speed limit I saw in my travels to Japan was 80 kph on an urban expressway.)

Energy conversions are inherently inefficient, so improvements in processing any particular energy conversion needs to be extremely efficient to offset the losses from additional conversions.

ICE converts energy from chemical > heat > mechanical.
Throw in series hybrid and the process is chemical > heat > mechanical > electrical > chemical > electrical > mechanical.

The electro-chemical conversions are more efficient than the initial chemical > heat conversions, but they still represent loss of efficiency.

If internal combustion ever got to say 70% efficiency, it would be game over for alternatives. The density of fossil fuels combined with high efficiency conversion would be an insurmountable obstacle. That doesn't appear likely, so we will see EV powertrains begin to displace ICE.

Exactly.


IIRC the Volt could be driven on ICE power when the batteries were low, so it's not a serial hybrid at all.


Wrightspeed has been proposing that approach mostly for trucks and buses. Had it provided a similar driveline for something like a Jeep Wrangler or the compact trucks, maybe there would be a good chance for success in the fleet market.

Ernie Rogers, a former member . . .
 

. . . provided a white paper calculating that the application of the Atkinson Cycle to a diesel engine could yield a tad over 60% thermal efficiency. Use of various materials in construction could pull out a few more percentages. Your 70% efficiency target is not that far off for the intrepid.

A single speed atkinized Diesel could also get away with a much more simplistic emissions system