Nissan shows ultra-frugal Micra DIG-S (Direct Injection Gasoline - Supercharger)
While electric, hybrid and diesel power trains have been grabbing headlines in recent times, work continues unabated on the good ol’ gasoline internal combustion engine and some significant headway has been realized with the news of a new Nissan Micra which will run a supercharged, direct injection 1.2 litre power-plant. The lightweight, low-friction, three-cylinder engine emits just 95g/km, produces 72kW (98PS) and 142Nm, and delivers combined cycle fuel economy figures of a staggering 68.9mpg. The car will debut in Geneva, will be available in both manual and CVT transmissions and will have a healthy top speed of 112mph.
Technical innovation has been packed into the engine. The DIG-S uses the Miller cycle and direct petrol injection to raise the compression ratio to 13 to 1 for greater combustion efficiency and a supercharger for instant throttle response and added power.
By minimizing heat, friction and pumping losses as much a possible, Nissan's engineers have created an engine that sets the standard for the rest of the industry. Its three-cylinder configuration gives many benefits including less weight and further reductions in friction loss, thanks to having fewer moving parts. Further gains are made thanks to the adoption of advanced engine management systems with Start/Stop and energy regeneration.
One of the biggest advantages of a small car with such a frugal engine are very low running costs, not just from the fuel economy but also thanks to tax concessions based on its emissions and to lower servicing bills from the smaller engine. For example, cars producing less than 100g/km of CO2 attract no annual road tax in the UK and are exempt from London’s daily congestion charge.
The DIG-S will be given its European debut at the Geneva Motor Show (March 3-13) with sales starting mid-year.
About the Author
Mike grew up thinking he would become a mathematician, accidentally started motorcycle racing, got a job writing road tests for a motorcycle magazine while at university, and became a writer. As a travelling photojournalist during his early career, his work was published in a dozen languages across 20+ countries. He went on to edit or manage over 50 print publications, with target audiences ranging from pensioners to plumbers, many different sports, many car and motorcycle magazines, with many more in the fields of communication - narrow subject magazines on topics such as advertising, marketing, visual communications, design, presentation and direct marketing. Then came the internet and Mike managed internet projects for Australia's largest multimedia company, Telstra.com.au (Australia's largest Telco), Seek.com.au (Australia's largest employment site), top100.com.au, hitwise.com, and a dozen other internet start-ups before founding Gizmag in 2002. Now he writes and thinks.
All articles by Mike Hanlon
bergamot69 very good explanation! Thank you. :-)
For a 68.9mpg economy, I should not be out of place to ask what is its 0-60 seconds.
Just guessing 9-10 second range would probably be about tops to 60 mph but they do not list the weight of vehicle. However I doubt any faster than that would be feasible.
O.K. for the most part I kind of like this car and there is a need for cars like this, BUT I can\'t understand how come they can take a 1.2 liter motor with this kind of compression and add a supercharger and only get 97 H.P.? I have a motorcycle with 11.5:1 compression and no supercharger and I have about 150 H.P. where did all the power go out of it? Just curios is all. :-)
@mrhuckfinYou have to understand the fundamental differences between car engines and those found in sportsbikes.A sportsbike is not designed with very high mileages in mind. It is designed to transport only the rider (maybe with one passenger on a limited basis) and a small amount of luggage. The engine is usually bespoke to the bike itself- and usually is an actual structural member in its own right- and for these reasons it is made as light as possible. Therefore, it needs to only generate a limited amount of torque as motorbikes tend to rely more on horsepower for performance (ie engine speed versus low-down slugging power).By comparison, a small car needs to be able to transport 4 adults (5 at a squeeze), plus luggage, and possibly a trailer- so needs to be able to provide far more torque. The engine has to be built for far higher milages (and Nissans traditionally go on forever as long as you change the oil). The engine can\'t be structural because of the need for crash-worthiness).Engine designers have to achieve an ideal compromise between horsepower and torque depending on application. You can have a 200hp farm tractor and a 200hp sportscar. if you swapped engines you\'d have the world\'s slowest sportscar and a tractor that couldn\'t pull the skin off a rice pudding. 97hp is a healthy output for a small car- especially one tuned for economy. I think you\'d find that it would give pretty good performance on the road, as long as you weren\'t expecting to go racing Porsches off the lights.
This is great! Finally, a company who is capitalizing on the benefits of direct injection. Combine this with a turbo instead for even higher efficiency, shove it in the back of a car to drive the rear wheels with a 15hp alternator/motor in series with the engine/trans, downsize it to 800cc, install a small battery and put a 2 small 15 hp motors in the front wheels to make the most of regenerative breaking. Then you\'ve got an AWD, 145 peak hp car that should edge up towards 100mpg!Rear wheel drive makes for such a nice platform, and since it is such a small engine anyway it shouldn\'t be too hard to package it. The in-wheel front electric motors wouldn\'t need to be large, they don\'t need to achieve 15hp steady state, only for 5 second bursts or so. Plus, they have abundant cooling considering they are in the wheel. We aren\'t making a performance car, so I\'m not too worried about unsprung weight, but you could use copper-clad aluminum wire in the windings to lighten it up. The little engine/trans in the back would probably be lighter than this Nissan\'s, the alternator/motor that you add to the trans shouldn\'t add weight as it would negate the regular alternator and starter motor, which on this Nissan is probably a little heavier than usual due to start/stop. I\'d also make that engine a flat 4 for packaging considerations.If you could keep the weight down to 3200lbs- or so, it wouldn\'t be too much of a slug. With 45 hp coming from the electric motors it would move off the line well, and the turbocharged 800cc engine will take care of the rest. With that much electric power, you should be able to tool around town on electric alone (and you\'d still have AWD!). The only problem is complexity, I\'d rather just build an all electric car , but that would be a waste of this new direct injection technology they\'ve spent so much money on!
The development of this vehicle is significant technologically in that its mpg surpasses many hybrids presently on the market. It may change the minds of people\'s who are considering the purchase of hybrids. I believe that Nissan has a good product to offer. I hope that in the future, they will also place just as much effort into developing the Micra DIG-S body that will be light and aerodynamic.
I\'m mystified by the entire automotive industry\'s refusal to use the two cheapest and easiest yet highest gain adaptations for the gain of power and efficiency and reduction of emissions...
High voltage multi-spark ignitions and static charge fuel atomizers
The use of these technologies collectively can boost the power of an engine by anywhere from 10-40% and the efficiency anywhere from 20-50% realistically, depending on the inherent efficiencies of the engine.
I\'m not opposed to direct injection, multi-valves and induction chargers, but they would be wise to make cheaper improvements that yield higher gains first.
This car does indeed present an alternative to hybrid vehicles. People are beginning to realize the \"rest of the story\" on hybrids. They have a huge carbon footprint and the mileage isn\'t that great. (Even my old Jetta TDI gets about the same mileage around town and better mileage on the hi-way.)
The production of batteries and other parts, shipping and manufacture of hybrids have a huge impact, much larger than on a non-hybrid.
High voltage multispark. I\'m going to need some clarification on this one, last I checked most spark plugs are firing with voltages in the tens of thousands. And multiple sparks? This is technically already being used on every ICE aircraft engine today, plus the modern day Hemi engines. Proper fuel atomization is currently being researched in the form of HCCI, and is no simple or cheap feat.
Nonetheless, if you really believe that the use of multispark and fuel atomizers can \"realistically\" increase an ICE engine\'s efficiency 50%, then I\'m willing to bet that most of the engineering decisions that the car companies make \"mystify\" you.
I just don\'t understand why they don\'t put \"bipolar\" magnets on the fuel line and install the \"tornado\" in the intake! That would increase efficiency at least 378%! Right?
What is the curb weight, drag, and acceleration? Tell me this and I\'ll know if they are serious about making an economy car.
When will it hit US showrooms?
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