Mercedes hits 50% efficiency in IC engine

[Ecky]

Meanwhile Honda built a mass-market engine almost 2 decades ago which was within a hair of 40% on street fuel, without the Atkinson cycle or a turbine in the exhaust.

[cRiPpLe_rOoStEr]

Originally Posted by Stubby79

With the kinds of RPMs they spin at, getting higher voltages would be really easy...kinda annoying that they haven't put these on hybrid production cars by now.

Considering the more intermittent operation of a hybrid's engine in heavy city traffic, and that many hybrids still resort to natural aspiration even when a similar non-hybrid is turbocharged (i.e. the Lexus NX), I'm not sure how much beneficial it would be. OTOH it would be perfect for a Diesel, since nowadays it's practically impossible to get them compliant to the stricter emission requirements relying on natural aspiration.

[sendler]

It's a great idea to harvest electricty from the otherwise wasted exhaust gas but that gen set turbo is just way too expensive for passenger cars.

[sendler]

Modern engines such as in the newest Prius are as efficient as they can get and still meet emissions. Whatever they did in the past can't hold a candle to these modern, high egr, Atkinson hybrids.

[cRiPpLe_rOoStEr]

Originally Posted by sendler

Modern engines such as in the newest Prius are as efficient as they can get and still meet emissions. Whatever they did in the past can't hold a candle to these modern, high egr, Atkinson hybrids.

One thing I consider quite intriguing is the hybrid versions of the Camry, the RAV4 and the Lexus NX being fitted with a dual-injection setup, while the Prius retains the port-injection only. Anyway, since the engine fitted to them is from the same series as the turbocharged one currently available in the Lexus NX, which also features dual-injection and a variable cam phasing that can also lead to the Atkinson effect which became mainstream in the hybrids, it would be at least interesting to see how such engine could perform in a hybrid if fitted with some sort of motor-generator coupled to the turbocharger in a way similar to what is done in some aircraft turbine engines.