Moore's Law & Hybrids

Sometimes we zoom down the road without knowing exactly where we are going. Then, it’s time to stop and ask for directions. When that happens on our drive to sustainable transportation strategies, we give a call to John DeCicco, senior fellow at Environmental Defense.

Moore’s Law is the empirical observation in 1965 that the number of transistors on an integrated circuit for minimum component cost, doubles every 24 months. It is attributed to Gordon E. Moore, co-founder of Intel. So, the speed and storage capacity of computers keeps going through the roof. Why can’t this happen for vehicle efficiency?


In recent years, the performance and capabilities of computer chips has increased exponentially. This growth is commonly referred to as Moore’s Law. Computer controls and batteries lie at the heart of hybrid cars. Can Moore’s Law applied to hybrids mean exponential gains in fuel efficiency?

John’s Reply

If only that were so! But until someone actually invents StarTrek-style matter transporters to transmit bodies and baggage in the form of bits and bytes—in other words, "beam us up" as data streams—Moore’s Law won’t be able to supersede the laws of motion.

Computer chips process information, which for practical purposes is massless. That’s why computer technologists can keep cramming more circuits onto chips, slashing the space and time scales for moving information and doubling processor power every two years.

Moving matter, however, is a different story. Bodies and baggage (and batteries) have real mass and take up real space. Even a very streamlined car with a perfectly efficient powertrain will require a certain minimum amount of energy to move it a given distance. Adding in all the creature comforts, performance desires and safety features we expect in our vehicles, and then factoring in the laws of physics, one soon bumps into serious practical limits for fuel efficiency. Although some advanced prime movers, such as fuel cells, do not have the same thermodynamic limits of combustion engines, they still face limitations in electrochemical energy conversion efficiency. Speaking of electrochemistry, batteries certainly have not seen Moore’s Law-like progress. Battery technology is progressing, but incrementally and often frustratingly slowly, whether the application is laptops, cell phones or cars.

Hybrid drive can indeed help any propulsion system maximize its efficiency by smoothing energy use over the variable loads of a driving cycle, avoiding fuel burn during times of minimal energy need, and recovering energy otherwise lost to braking. But hybrid technology does no more than enable engineers to achieve efficiencies that come closer to the basic limits rooted in the form and function of the vehicle. It offers no Moore’s Law magic that would let fuel efficiency grow by leaps and bounds.

That’s not to say that steady—linear, shall we say, rather than exponential—gains in fuel efficiency can’t be made. Many technology refinements offer higher fuel economy and the advent of hybrids extends that potential even further. It is not, however, a game-changer in any fundamental sense of the term. The same desires for larger, faster, more luxurious and powerful vehicles that consume other forms of automotive engineering progress can also devour much of the efficiency benefit from hybridization. In short, even technology as wonderful as hybrid drive can’t "beam us up" beyond our ability—or inability—to make fuel economy itself a priority in automotive choice and design.

Based in Ann Arbor, Michigan, John DeCicco is a Ph.D. mechanical engineer who specializes in automotive strategies for Environmental Defense, where he evaluates vehicle technologies and helps develop market-based policies for addressing the car-climate challenge. John was the original creator of ACEEE’s Green Book, which references for the its Gas Mileage Impact Calculator and lists of the "greenest" and "meanest" vehicles, and he has published widely-cited technical studies on automotive energy and climate issues.

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  • Saad Rahim

    Moore’s law increased performance by increasing power consumption. From an environmental perspective, Moore’s Law is probably responsible for garbage, energy consumption and pollutants comparable to automobile industry.

    And by the way, it has never been applied to batteries.

  • Paul Burnett

    There’s an old joke that goes something like “If automotive technology had kept pace with Silicon Valley, motorists could buy a V-32 engine that goes 10,000 m.p.h. or a 30-pound car that gets 1,000 miles a gallon — either one at a sticker price of less than $50. Detroit’s response: “OK. But who would want a car that crashes twice a day?” (Later versions attributed to Bill Gates with a response from General Motors are bogus.)

    The payload size of cars (people) doesn’t change, and the overhead mass/volume of associated hardware can only shrink so much – nothing much smaller than a SmartCar can possibly transport two people inside itself. That’s the end of that evolutionary path.

  • Patrick Leonard

    We can’t really speak of technology evolution on cars since the technology evolution has been stopped under pressure from oil interest as soon as the EV1 was produced.

    If computers technology evolution had been stopped by the counting frame builders interest we would still be waiting for the first PC to appear on the market.

    The real car technology evolution will only start when the first plug-in flex-fuel hybrid comes on the market.

    From then on, and only from then on, will we see, near zero friction axels, Bose electromagnetic suspensions, 99% efficiency regenerative braking, reversible thermoacoustic heat pumps, vehicle integrated photovoltaics and aerospike front air spreaders. All items that will make cars a genuine technology and not an oilies on purpose oil consumption machines.

  • John Acheson

    Taking into consideration the costs from getting a barrel of oil into gasoline ready for filling up a vehicle and pushing it around Earth, Moore’s law impacts one very important variable over them all: efficiency.

    Every vehicle is a hybrid and uses electricity except purebred diesels. Porsche built the first hybrid. It was also the first FWD hybrid as well as the first hybrid racecar. Oh, and it also was the first hybrid without a tranny. How efficient? It was estimated at 83% circa 1900.

    Most internal combustion engine vehicles are about 20%. Yep, for every 10 barrels of oil, 8 end up in the air or heat things up. Only 2 end up turning the wheels.

    100 years ago, Porsche turned those 8 into propulsion. So we’ve been going backwards about .5% per year until the Prius…

    Only Toyota has released efficiency figures. The first gen Prius or 2nd gen US Prius is rated at 32%. The following generation upped that to 37% or an incredible 1-2% per year eclipsing the last 100 years of regression.

    Combined with a 80-90% oil to gasoline value chain, the Prius only throws away 6 or 7 barrels of oil per 10 pulled out of the ground.

    One barrel of oil or one gallon a gas saved for every 10 doesn’t sound like much in volume, but in acceleration, it’s a leap forward.

    Acheson’s law says that vehicle efficiency will improve an average of 1% per year until we get back to Porsche’s 83%. Then we will convert back to electrics and continue the progression…

    Imagine how long a battery or tank of fuel or fuel cell or accumulator or liquid or gas battery will last at 80%?

    That’s more scary than Moore’s law because it displaces oil/gasoline excise taxes, sales taxes, income taxes, property taxes, company profits, sales, jobs, communties and economies.

    On the other hand, each 1% in efficiency improvement can gross an estimated one billion dollars worth of marketshare, jobs, local economies, sales tax revenues, income and other streams of money.

    Every transportation and energy company has a choice, find more natural resources or improve efficiency…

    PS If you’re way ahead of me and thinking about electric cars, according to the VP of sales at Tesla, the Roadster is about 88% efficient with a 90% battery pack. Yes it has regenerative braking, so you get .9x.88 back out every time you slow down. BUT, many electric grids around the world are about half as efficient as the gasoline and diesel value chains.

    Then again, electric companies are elephants in the room next to the oil giants with big ag in the background. Would you rather have big oil, big ag or big energy powering your household when the ice caps are gone in 2050?

  • murphy

    I think that the US motor indudtry needs to make some very bold steps to keep-up with Toyota in Hybrid vehicle technology. They are well behind on engine management systems for hybrids and have no volume base to drive unique hybrid component costs down. In order to get ahead they need to successfully harness the innovation skills of 3rd party technology suppliers in the hybrid area. Circa 50% of the extra cost of a hybrid drive is in the battery. Why not work with there existing OEM suppliers to quickly find a lower cost solution in this area. There must also be a change in focus to fuel efficiency. With $60 per barrel oil here to stay and a Goverment that is much more likely to introduce a green tax to encourage fuel efficiency there is a real need to respond even incrementally. Not sure if lobbying efforts are also not misdirected. Why not bring in deisel engines which are much more efficient and where aAmericans still have a lead.