Super-efficient Israeli engine bids to power car revolution

Posted: October 29, 2016 by oldbrew in innovation, Travel
Gal Fridman, co-founder of Aquarius Engines, with the firm's single-piston car engine [image credit: / Aquarius]

Gal Fridman, co-founder of Aquarius Engines, with the firm’s single-piston car engine [image credit: / Aquarius]

Too good to be true? If not, what might the future hold for this innovation? takes a look.

An Israeli firm says a super-efficient engine it has created could drastically reduce fuel consumption and help power an auto industry revolution as manufacturers search for environmentally sound alternatives.

Industry analysts, however, question the reinvented internal combustion engine’s chances of success at a time when purely electric car technology is advancing and attracting investors.

The invention from Israeli-based Aquarius Engines is currently being discussed by France’s Peugeot, the firm said.

Aquarius says the cost of the engine will be as low as $100 (92 euros). According to the firm, the engine can allow cars to travel more than 1,600 kilometres (990 miles) on a single tank of fuel, more than double current distances.

Aquarius’s technology works by stripping back the traditional engine under the bonnet. It replaces the combustion engine with its multiple pistons thrusting up and down with a single piston that goes side-to-side.

It has fewer than 20 parts and a single action, the company said. In tests by the German engineering company FEV, the Aquarius engine’s efficiency was more than double that of traditional engines.

Aquarius’s Fridman argued there is too much “hype” around purely electric cars, and that their actual popularity is limited because of small ranges and high prices.

“50,000 units is nothing,” he said of Tesla’s projected sales.
“It is amazing as there has been a push from governments, municipalities, etc. And still after 15 years the segment is not really successful.”

Full report: Israel firm wants super-efficient engine to power car revolution |

  1. oldbrew says:

    Re hybrid vehicles:
    In a rethink of engine fundamentals, Aquarius has pared the range extender down to a single piston that blasts to and fro inside a valveless 600cc cylinder, generating power from electromagnetic coils with each stroke. It delivers more than twice the overall energy efficiency of a typical combustion engine, according to simulations by German engineering firm FEV. 

    read more:

  2. Curious George says:

    It still has Carnot Cycle limitations. And it produces a rocking movement, which will have to be compensated for and converted to a rotational movement. This is a pure hype. The efficiency hype seems to be based on models, not on a real measurement. I hope they will come back with real numbers soon.

  3. oldmanK says:

    The link at the top shows pics of an expensive contraption with plenty of sealing problems and friction losses -and wear. Petrol or diesel, still has the same thermodynamic limitations. What’s behind it?

  4. Jerry says:

    I will take a guess at answering oldmanK’s question. I seem to remember conventional internal combustion engines are very inefficient in converting the energy in gasoline and diesel fuel to useable energy out of the crankshaft. So, perhaps this engine has greatly approved this efficiency. But, as others have pointed out, the side-to-side motion of the piston still requires a means of converting the translational piston motion into rotating energy for the crankshaft. All of the above is just a wild guess with, in part, the objective of stimulating further discussion.

  5. oldbrew says:

    Jerry says:
    ‘But, as others have pointed out, the side-to-side motion of the piston still requires a means of converting the translational piston motion into rotating energy for the crankshaft.’

    Not if it’s used as a range extender for a hybrid vehicle. Then it just generates extra electricity which is already being used to turn the wheels. [see: oldbrew says: October 29, 2016 at 4:42 pm]

  6. Jerry says:

    But, this sounds like extracting the same rotating energy twice from a single source. First is the energy to drive the wheels. Second is the additional extracted energy required to produce the electrical current. The latter cannot “piggyback” for free on the former. If electrical energy is indeed extracted from a shaft driving wheels, then the torque on the drive shaft must also increase. Fuel consumption will therefore increase.

    This is analogous to the electrical energy produced at hydro-power projects by extracting translational energy from flowing water to turn the turbines that produce electricity.

  7. pg sharrow says:

    An IC engine-generator that drives electric wheels is at least 20% more efficient then any mechanical drive. IC engines are more efficient the any Battery system can be at converting fuel to motive power. Only by putting a bureaucratic thumb on the scale can all electric cars be made to look good.
    Real engineers know that there is NO FREE LUNCH!
    An oscillating piston engine with electric generation can be nearly sealed except for the piston rings but this one also requires an external blower and fuel pump. It is very hard to beat a modern piston engine for efficiency and long life…pg

  8. fast says:

    For hybrids my bet would be on the stirling electric combination. Although all of these are long shots to accomplish much over the next ten years.

  9. oldbrew says:

    Wikipedia: ‘As an REEV is only propelled by the electric motor it can do away with the weight and cost associated with the gearbox transmission system typically used in internal combustion engine cars.’

    Range-extender engines
    By The Engineer

    ‘…the engine is not mechanically linked to the drivetrain’

  10. […] Source: Super-efficient Israeli engine bids to power car revolution | Tallbloke’s Talkshop […]

  11. ivan says:

    Jerry, in simple terms you have a piston that moves back and forth in a cylinder. This motion generates electricity by, I assume, magnetic induction – nothing rotating at this stage. From there the electricity may go to charge the battery – again nothing rotating, but it can also go to the electric motor/s that move the car – this is where rotation appears. There is no conflict or ‘piggybacking’ in any form – the engine does not directly produce any rotary output at all.

  12. oldmanK says:

    ivan says: […]. However the starting point is still a reciprocating piston of an Otto cycle. There is only one point of best efficiency–at full load and one particular speed. This means that excess power than is needed has to be stored in batteries. A range extender.

    I have come across similar. A half-baked idea that still sells. There will be no further interest than that.

  13. USteiner says:

    The article is a bit short on details on the technology of the engine, but things remind me strongly of the OPOC engine, “Opposed Piston Opposed Cylinder”:

    Details on the Chinese company’s website:

    Ecomotors came into play in 2011

    Inventor is an Austrian guy, who had been in charge of engine development at VW. However, VW was not interested. Investors in opoc are Khosla Ventures, Bill Gates, and other. Claims are 50% fewer parts, 50% lighter, 50% less fuel, and 20% lower cost.

    Questioned by a blogger Ecomotors stated “Production of the opoc engine is expected to begin in 2016.”

    The $100 per engine cost claimed by Aquarius Engines does look a bit dubious.

  14. USteiner says:

    An animated gif of the opoc is found here:

  15. oldmanK says:

    The picture shows something very different. It is single piston, double acting – firing on both sides-, single central air/fuel?(if not injection) inlet. Likely two stroke for high power/weight ratio. Power out from straight moving con-rod on either side via seals. Inlet valveless, out ??.

    Need not convert to rotary action if connected to reciprocating type generator -which then can serve as starter motor. Nice idea, but skeptical on claimed effcy.

  16. oldbrew says:

    Gates has a finger in the OPOC pie.

    ‘The OPOC engine is an opposed-piston 2-stroke engine. The OPOC is a reciprocating internal combustion engine in which each cylinder has a piston at both ends, and no cylinder head. There are no valves or a cylinder head.’

  17. John Silver says:

    Even I have invented that in the 80’s

  18. Looks like a single cylinder version of the Deltic diesel engine
    which was powering British trains in the 1950’s and 60s.

    Where’s the novelty?

  19. oldbrew says:

    B&T says: Where’s the novelty?

    You can hold the engine above your head – as shown 😉

  20. Oldbrew- I’m with you on that!

  21. Jerry says:

    For Oldbrew and Ivan: I understand both of your comments. My comment is independent of type of motion, whether translational or rotational motion. However, my point remains: the generation of the electrical field requires energy and its exploitation is thus not “free”.
    Interesting discussion.

  22. oldbrew says:

    Jerry: it’s powered by fuel like any other ICE.

  23. ivan says:

    From what I can see this is the IC adaptation of the Stirling engine with a linear alternator – not the most efficient but if it can be manufactured for the price stated we might see electric sars cars become viable for long distance travel.

  24. ivan says:

    Sorry, that should be electric cars

    Note to self; read carefully before hitting post button!

  25. oldbrew says:

    ‘we might see electric cars become viable for long distance travel’

    Viable perhaps, but value for money? Only a small portion of longer journeys is or would be electrically powered, i.e. not dependent on a fuel-burning range extender, but the buyer has to pay for two means of propulsion and haul heavy batteries everywhere.

  26. Jerry says:

    Oldbrew: agreed re your ICE comment. But this still does not address my point. The generation of the field will require more power/fuel than if it were not present. The field and any exploitation of it is not “free.” Addition power/fuel will be required.

  27. oldbrew says:

    Jerry: yes, but that’s what a range extender is.

    Under electric power only, the batteries have to ‘carry’ the range extender and its fuel as well as themselves. That’s the downside if you like, and the upside obviously is you can burn fuel to keep going when the stored battery power runs too low.

    Realistically EVs are for people who mainly want to do short journeys, and can afford to pay premium prices. And are willing to do so.

  28. Jerry says:

    Oldbrew: I understand. But the electrical energy has to come from somewhere. If it is from a coil around a shaft — wherever, it doesn’t matter — then that energy must be generated and accounted for and does not come free. To me, the original article implied that it did.
    About three weeks ago, I drove a Chevie Volt. It has a 70 mile electric range with fully charged battery and enough gasoline/petrol for 330 additional miles. I can certainly see some net saving from the electrical motor simply because the batteries, in part, are charged when the brakes are applied, recovering some of the kinetic energy as the vehicle slows and stops. So, kinetic energy can be partially or even mostly recovered. But it is a small part of the total energy provided by the batteries for typical driving. Further, the batteries and generator are heavy, so additional energy is required to accommodate that additional weight.
    The Volt was fun to drive but I am not going to buy one.

  29. oldbrew says:

    Several gallons of fuel also add to the weight. The hybrid is an admission that electric-only vehicles are inadequate.

  30. oldbrew says:

    Toyota raises the hybrid EV bar to 37 miles max. (in ideal conditions)

    ‘Toyota says its Prius Prime, a soon-to-be-launched plug-in electric version of the world’s top-selling gasoline hybrid, will use lithium-ion batteries, with enough energy to make the car go around 60 kms (37.3 miles) when fully charged before the gasoline engine kicks in. Because of different methodology in measuring a car’s electric mode range, the Prime’s 60 km range will be listed in the United States as around 25 miles (40.2 kms).’–finance.html

  31. jim says:

    Actually, the combination engines were around prior to trains. The Detroit musems didn’t have one, they have an early electric, but the same time period had an pulled generator, behind a electric truck, from the ww1 era. Remember seeing that contraption, for getting to the front, must have been French? But I am delighted to see a lightweight upcoming option for future vehicles. Now, if they can produce power with it, one or two generators, would power a big heavy haul truck? Neat.

  32. oldbrew says:

    jim: the engine in question is 600 cc so we’d need to know how much electricity it can generate in a given time period, and how much power that would translate to.

  33. oldbrew says:

    Another pic of the metal in question…


  34. oldmanK says:

    The finned production unit shows two spark plugs. Its a double acting single piston, unlubricated so 2strk + lube; requires many accessories (air-charger, ecu, etc).

    But upon consideration, nothing simple about it. A two stroke motor hoe engine of same capacity is simpler, less parts and less machining to produce, with rotational output that is more convenient. This is unbalanced too (shakes side to side).

    Two stroke were being banned due to hydrocarbon pollution from added lube in fuel. The unit can be made to work 4strk but unbalance gets worse and power/wt ratio reduces by half.

  35. catweazle666 says:

    Free-piston engines have been around since the late 1920s.

    Click to access FPEreview.pdf

    The efficiency is utterly constrained by the good old Carnot cycle, the limits of which we have pretty well approached decades ago, so any claims about improvements in excess of a per cent or so are just blowing smoke.

    The very compact Deltic engine was in fact an adaption of a Napier marine design, incidentally.

    Then there is the old Commer TS3 unit, another very compact unit for its output.

  36. oldmanK says:

    There may be another angle to this ‘curiosity’. A patent get-around.

  37. USteiner says:

    Nissan just announced their new e-Power system, another variant of an electric drive. This is one which I myself had envisioned as a viable system for all users, but nobody else seemed to be interested.

    It is always propelled by an electric engine, but it does have a combustion engine on board which has the sole duty of generating electricity and feeding it to the battery on board (or directly to the e-motor when needed). This battery is only “1/20th of the battery in the present Nissan Leaf EV”. Since this has a 24 or 30 kWh, this amounts to 1…2 kWh, i.e. only about the size of starter batteries of today’s cars. The two batteries used fit under the front seat (as seen in the video).

    It does not even have a connection for a charger, so no plug-in charging possible nor needed.

    Your range is thus limited to the size of the gas tank, and you refuel as today in a few minutes.

    The benefit comes from the differential between the efficiency of the combustion engine at best performance, and the efficiency at typical usage. For gasoline engines the best efficiency is 36%, while at typical city usage it is 15%. (Diesel: 41% and 18%). If the electric generator and battery work at 75%, which I think is possible, such an e-Power car might do the city with 36%*75%=27% instead of 15%, or almost doubled efficiency, or halved fuel consumption.

    And in fact, in the video they do state the benefit to come only for similar stop-and-go traffic.

    The battery costs for as little as 1…2 kWh are almost negligible (and could even be lead-acid batteries, weight also does not matter much at this scale).

    But now you have two systems in the car. Hence such combo-systems will benefit greatly from simple, light, cheap combustion engines as those discussed in this post!