Quote from https://www.autoguide.com/auto-news/201 ... le-ev.html
Mazda: Emissions of Skyactiv-X Engine Comparable to an EV
At the forefront of Mazda’s green-vehicle strategy is its Skyactiv-X internal combustion engine. This might not seem very earth-friendly, but allow the automaker to explain.
Because two-thirds of global electricity production relies on fossil fuels, Mazda believes the “tank-to-wheel” evaluation currently used to render electric vehicles “emissions free” is disingenuous. Instead, it proposes the industry adopt a “well-to-wheel” evaluation, which takes into account fuel extraction, shipping, and manufacturing when deciding a vehicle’s CO2 emissions.
For example, a mid-sized electric car consumes around 20 kilowatt-hours of electricity per 100 kilometers.
Producing this much power at a coal plant translates into 200g of C02 per km.
It would translate into 156g/km if the power were sourced from a gas plant, and to 100g/km from a natural gas plant.
It says the average well-to-wheel emissions of an EV are about 128g/km, while its current Skyactiv-G gas engine produces about 142g/km.
With the new Skyactiv-X compression ignition engine set to make huge gains in efficiency, Mazda is certain the engine will return impressive well-to-wheel emissions and will be more earth-friendly than many EVs being charged with fossil fuel-sourced energy.
“Committed to the principal of the right solution at the right time, Mazda has concluded that, until the growing quantity of power from renewables replaces the dirtiest forms of electricity generation such as brown coal, electric powertrains do not currently satisfy to society’s wish for a drastic reduction in greenhouse gas emissions,” it said.
End of Quote
Here Mazda’s engineer is explaining the SkyActiv-X and how it will affect the car driving:
After Mazda announced their SkyActiv-X tech, Toyota (the world leader n Hybrids?) increased their share in Mazda.
Back to the OPRE 2-stroke and its potential.
Even with normal “2-stroke brake thermal efficiency” (BTE about 20%) the Portable Flyer would consume a dozen times less fuel than the state-of-the-art Jet Packs (Zapata, Mayman, Browning), would pollute a dozen times less, and would have a dozen times longer range (taking off with the same quantity of fuel).
With its longer piston dwell, with the low friction losses of the 2-strokes and, potentially with HCCI combustion (and thereby lean-burn and cool combustion, i.e. lower heat losses and lower heat loads on the materials, escpecially on the lubricant film), the OPRE-Tilting seems capable for doubling-up the BTE.
These are for the Portable Flyer (based on the OPRE Tilting engines).
But the OPRE engine
and PatOP engine (which is the single crankshaft version of the OPRE),
with direct injection (either Diesels, or spark ignition or HCCI),
with their “pulling rod” architecture (which substantially increases the piston dwell at the CDC (Combustion Dead Center), increasing the time provided to the fuel for more efficient / clean combustion, increasing the “constant volume portion of the combustion” and the “actual expansion ratio”, substantially improves the BTE),
and with their “four-stroke-like lubrication (check the specific lube consumption of the Achates Power 2-strokes, whose architecture is not as good as the architecture of the OPRE-PatOP in this area, with the trust loads taken away from hot ports, at the cool side of the cylinder), can make the 2-strokes cleaner than the best existing 4-strokes.
As Mazda says:
"until the growing quantity of power from renewables replaces the dirtiest forms of electricity generation"
. . .