NHTSA Modeling and Technology Projections Underlying the Proposed CAFE Target of 34.1 mpg by MY 2016
21 September 2009
| Three of the NHTSA scenarios for penetration of technologies for passenger cars for MY 2016. Shown are slow growth (3%), the preferred proposed alternative, and the maximum potential. Data: Preliminary Regulatory Impact Analysis. Click to enlarge. |
On 15 Sep, NHTSA and the US EPA proposed a joint rulemaking on fuel economy and greenhouse gas emissions for light duty vehicles: an average new car 34.1 mpg and 250 g CO2/mile for model year 2016. (The 250 g/mile of CO2 equivalent emissions limit by EPA is equivalent to 35.5 mpg if the automotive industry were to meet this CO2 level just through fuel economy improvements.) (Earlier post.)
Behind the targets is a significant amount of modeling, including revisions to certain aspects of the Volpe modeling process, such as the inputs, data, modeling techniques, and the constraints used in assessing appropriate stringency for future CAFE standards. In developing the proposed preferred alternative for the rulemaking, NHTSA also projected technology penetration and associated costs for the vehicle fleet. NHTSA details the modeling and the projections in the “Preliminary Regulatory Impact Analysis”, and the NHTSA/EPA “Draft Joint Technical Support Document”.
| Three of the NHTSA scenarios for penetration of technologies for light trucks for MY 2016. Shown are slow growth (3%), the preferred proposed alternative, and the maximum potential. Data: Preliminary Regulatory Impact Analysis. Click to enlarge. |
In an earlier rulemaking, NHTSA reformed the corporate average fuel economy (CAFE) standards with a size-based standard based on footprint. (Earlier post.) The new proposed rulemaking continues this approach; a continuous mathematical function provides a separate fuel economy target for each footprint. Individual manufacturers will be required to comply with a single fuel economy level that is based on the distribution of its production among the footprints of its vehicles.
Although the same reformed CAFE scheme is required for both passenger cars and light trucks, they are established with different continuous mathematical functions specific to the vehicles’ design capabilities.
The baseline assumptions for the NHTSA proposed rulemaking differ from previous analyses. In the past, the baseline was the manufacturers’ confidential plans for each model year; in the new analysis, the baseline is each manufacturer’s MY 2008 fleet. NHTSA assumes that similar vehicles will be produced through MY 2016 and technologies are added to this baseline fleet to determine what mpg levels could be achieved with technologies. This approach, said the agency, is more transparent than relying on manufacturers’ confidential plans.
NHTSA examined eight scenarios examined include five alternatives that are annual percentage improvements over the baseline. The “Preferred Alternative” proposed in the rulemaking would require fuel economy levels that are between the 4 and 5% annual increase alternatives.
Technologies. In developing technology inputs for MY 2012-2016 standards, NHTSA and EPA reviewed, as requested by President Obama in his January 26 memorandum, the technology assumptions that NHTSA used in setting the MY 2011 standards and the comments that NHTSA received in response to its May 2008 NPRM.
The agencies also reviewed the technology input assumptions identified in EPA’s July 2008 Advanced Notice of Proposed Rulemaking and 2008 Staff Technical Report and supplemented their review with updated information from more current literature, new product plans and from EPA certification testing. The two agencies are continuing with their analysis, and will incorporate the upcoming National Academies update of the 2002 NAS Report, which presents technology effectiveness estimates.
The technologies considered by the NHTSA and EPA fall under the five broad categories of engine, transmission, vehicle, electrification/accessory, and hybrid technologies. The agencies did not consider technologies in the research stage because their effectiveness and/or costs are presently only known with greater levels of uncertainty.
Engine technologies
Low-friction lubricants: low viscosity and advanced low friction lubricants oils are now available with improved performance and better lubrication.
Reduction of engine friction losses: can be achieved through low-tension piston rings, roller cam followers, improved material coatings, more optimal thermal management, piston surface treatments, and other improvements in the design of engine components and subsystems that improve engine operation.
Conversion to dual overhead cam with dual cam phasing: as applied to overhead valves designed to increase the air flow with more than two valves per cylinder and reduce pumping losses.
Cylinder deactivation: deactivates the intake and exhaust valves and prevents fuel injection into some cylinders during light-load operation. The engine runs temporarily as though it were a smaller engine which substantially reduces pumping losses.
Variable valve timing: alters the timing or phase of the intake valve, exhaust valve, or both, primarily to reduce pumping losses, increase specific power, and control residual gases.
Discrete variable valve lift: increases efficiency by optimizing air flow over a broader range of engine operation which reduces pumping losses. Accomplished by controlled switching between two or more cam profile lobe heights.
Continuous variable valve lift: is an electromechanically controlled system in which cam period and phasing is changed as lift height is controlled. This yields a wide range of performance optimization and volumetric efficiency, including enabling the engine to be valve throttled.
Stoichiometric gasoline direct-injection technology: injects fuel at high pressure directly into the combustion chamber to improve cooling of the air/fuel charge within the cylinder, which allows for higher compression ratios and increased thermodynamic efficiency.
Combustion restart (CBRST): can be used in conjunction with gasoline direct-injection systems to enable idle-off or start-stop functionality. Similar to other start-stop technologies, additional enablers, such as electric power steering, accessory drive components, and auxiliary oil pump, might be required.
Turbocharging and downsizing (TRBDS): increases the available airflow and specific power level, allowing a reduced engine size while maintaining performance. This reduces pumping losses at lighter loads in comparison to a larger engine.
Exhaust-gas recirculation boost: increases the exhaust-gas recirculation used in the combustion process to increase thermal efficiency and reduce pumping losses.
Diesel engines: have several characteristics that give superior fuel efficiency, including reduced pumping losses due to lack of (or greatly reduced) throttling, and a combustion cycle that operates at a higher compression ratio, with a very lean air/fuel mixture, than an equivalent-performance gasoline engine. This technology requires additional enablers, such as NOx trap catalyst after-treatment or selective catalytic reduction NOx after-treatment.
Transmission technologies
Improved automatic transmission controls: optimizes shift schedule to maximize fuel efficiency under wide ranging conditions, and minimizes losses associated with torque converter slip through lock-up or modulation.
Six-, seven-, and eight-speed automatic transmissions: the gear ratio spacing and transmission ratio are optimized for a broader range of engine operating conditions.
Dual clutch or automated shift manual transmissions: are similar to manual transmissions, but the vehicle controls shifting and launch functions. A dual clutch automated shift manual transmission uses separate clutches for even numbered and odd-numbered gears, so the next expected gear is pre-selected, which allows for faster and smoother shifting.
Continuously variable transmission: commonly uses V-shaped pulleys connected by a metal belt rather than gears to provide ratios for operation. Unlike manual and automatic transmissions with fixed transmission ratios, continuously variable transmissions can provide fully variable transmission ratios with an infinite number of gears, enabling finer optimization of transmission torque multiplication under different operating conditions so that the powertrain can operate at its optimum efficiency.
Manual 6-speed transmission: offers an additional gear ratio, often with a higher overdrive gear ratio, than a 5-speed manual transmission.
Vehicle technologies
Low-rolling-resistance tires: have characteristics that reduce frictional losses associated with the energy dissipated in the deformation of the tires under load, therefore reducing the energy needed to move the vehicle.
Low-drag brakes: reduce the sliding friction of disc brake pads on rotors when the brakes are not engaged because the brake pads are pulled away from the rotors.
Front or secondary axle disconnect for four-wheel drive systems: provides a torque distribution disconnect between front and rear axles when torque is not required for the non-driving axle. This results in the reduction of associated parasitic energy losses.
Aerodynamic drag reduction: is achieved by changing vehicle shape or reducing frontal area, including skirts, air dams, underbody covers, and more aerodynamic side view mirrors.
Mass reduction and material substitution: Mass reduction encompasses a variety of techniques ranging from improved design and better component integration to application of lighter and higher-strength materials. Mass reduction is further compounded by reductions in engine power and ancillary systems (transmission, steering, brakes, suspension, etc.).
Electrification/accessory and hybrid technology
Electric power steering (EPS): is an electrically-assisted steering system that has advantages over traditional hydraulic power steering because it replaces a continuously operated hydraulic pump, thereby reducing parasitic losses from the accessory drive.
Improved accessories (IACC): may include high efficiency alternators, electrically driven (i.e., on-demand) water pumps and cooling fans. This excludes other electrical accessories such as electric oil pumps and electrically driven air conditioner compressors.
Air Conditioner Systems: These technologies include improved hoses, connectors and seals for leakage control. They also include improved compressors, expansion valves, heat exchangers and the control of these components for the purposes of improving tailpipe CO2 emissions as a result of A/C use. These technologies are covered separately in the EPA RIA.
12-volt micro-hybrid (MHEV): also known as idle-stop or start stop and commonly implemented as a 12-volt belt-driven integrated starter-generator, this is the most basic hybrid system that facilitates idle-stop capability. Along with other enablers, this system replaces a common alternator with an enhanced power starter-alternator, both belt driven, and a revised accessory drive system.
Higher Voltage Stop-Start/Belt Integrated Starter Generator (BISG): provides idle-stop capability and uses a high voltage battery with increased energy capacity over typical automotive batteries. The higher system voltage allows the use of a smaller, more powerful electric motor and reduces the weight of the motor, inverter, and battery wiring harnesses. This system replaces a standard alternator with an enhanced power, higher voltage, higher efficiency starter-alternator, that is belt driven and that can recover braking energy while the vehicle slows down (regenerative braking).
Integrated Motor Assist (IMA)/Crank integrated starter generator (CISG): provides idle-stop capability and uses a high voltage battery with increased energy capacity over typical automotive batteries. The higher system voltage allows the use of a smaller, more powerful electric motor and reduces the weight of the motor, inverter, and battery wiring harnesses. This system replaces a standard alternator with an enhanced power, higher voltage, higher efficiency starter-alternator that is crankshaft mounted and can recover braking energy while the vehicle slows down (regenerative braking).
2-mode hybrid (2MHEV): is a hybrid electric drive system that uses an adaptation of a conventional stepped-ratio automatic transmission by replacing some of the transmission clutches with two electric motors that control the ratio of engine speed to vehicle speed, while clutches allow the motors to be bypassed. This improves both the transmission torque capacity for heavy-duty applications and reduces fuel consumption and CO2 emissions at highway speeds relative to other types of hybrid electric drive systems.
Power-split hybrid (PSHEV): a hybrid electric drive system that replaces the traditional transmission with a single planetary gearset and a motor/generator. This motor/generator uses the engine to either charge the battery or supply additional power to the drive motor. A second, more powerful motor/generator is permanently connected to the vehicle’s final drive and always turns with the wheels. The planetary gear splits engine power between the first motor/generator and the drive motor to either charge the battery or supply power to the wheels.
Plug-in hybrid electric vehicles (PHEV): are hybrid electric vehicles with the means to charge their battery packs from an outside source of electricity (usually the electric grid). These vehicles have larger battery packs with more energy storage and a greater capability to be discharged. They also use a control system that allows the battery pack to be substantially depleted under electric-only or blended mechanical/electric operation.
Electric vehicles (EV): are vehicles with all-electric drive and with vehicle systems powered by energy-optimized batteries charged primarily from grid electricity.
Projected technology penetrations for the preferred alternative. EPA and NHTSA expect that automobile manufacturers will meet the proposed standards by utilizing technologies that are mainly available today, but with more widespread use across the light-duty vehicle fleet. With commercialization of electric vehicles and plug-in hybrids just beginning within the rulemaking period, their penetration in the modeled scenarios is negligible—0%, even by MY 2016, and even in the most aggressive scenario.
Among the results of the MY 2016 technology penetration projections under the preferred alternative scenario—i.e., the basis for the proposed CAFE rulemaking—based on total sales of 16.6 million units of MY 2016 vehicles are:
- Dual cam phasing: 61% for cars, 52% for trucks
- Stoichiometric Gasoline Direct Injection (GDI): 44% for cars, 56% for trucks
- Discrete variable valve lift on DOHC: 34% for cars, 33% for trucks
- Turbocharging and downsizing: 26% for cars, 15% for trucks
- Dual Clutch or Automated Manual Transmission: 61% for cars, 92% for trucks
- Electric Power Steering: 86% for cars, 96% for trucks
- Belt mounted Integrated Starter Generator: 33% for cars, 27% for trucks
- Power Split Hybrid: 5% for cars, 2% for trucks
- 2-mode hybrid and plug-in hybrid: 0% for both cars and trucks
- Mass Reduction (1.5%): 73% for cars, 71% for trucks
- Mass Reduction (3.5% to 8.5%): 32% for cars, 31% for trucks
Resources
Most, if not all, the technological changes mentionned could have been incorporated 10 years ago, not by 2016.
A CO2 level of 250 g/Km by 2016 is not serious. Fiat will reach the EU standard of 130 g/Km by 2010. By 2016 Fiat (a many others) may be below 100 g/Km.
Chrytsler may do much better than 250 g/Km if allowed to use Fiat's technologies.
Posted by: HarveyD | 21 September 2009 at 12:19 PM
@HarveyD I would prefer to describe 250g/Km as a travesty.
Also, it would be of interest to compare a list of technologies for over-the-road hauling with what seems to be a list intended for passenger vehicles.
Posted by: jcwinnie | 21 September 2009 at 03:00 PM
jwc:
And you could add that many people think that clean drinking water is a pasquinade, decent health care is a parody, public schools are a masquarade, public roads are not necessary etc.
Posted by: HarveyD | 21 September 2009 at 04:39 PM
Correction -- 250 g/MILE, not km.
The NHTSA/EPA targets are equivalent to 6.9 L/100km of fuel consumption and 155 g/km CO2.
--Mike
Posted by: mmillikin | 21 September 2009 at 06:52 PM
Of course virtually all of this technology could have been incorporated 10 years ago.
And the 70 mpg Honda Insight was for sale about 10 years ago.
And what?
It didn't sell. Not because of patents, or being crushed, or brain washing.
It didn't sell because no one wanted it.
It was the other "crushing" failure.
Posted by: ToppaTom | 21 September 2009 at 10:28 PM
Eliminate belts from an automobile entirely. All pumps, fans and compressors can be replaced by more efficient brushless permanent magnet motors.
When, more than ten years ago, I first learned of the Switched Reluctance company owned by Emerson, I thought-invented the flywheel motor-starter-alternator for start-stop operation of automobiles. It was also for low speed creeping in traffic jams. Several engines have now tried the concept.
Add electric engine valves and injectors and very high efficiency operation is possible. It also makes it much easier to move the vehicle with the "starter" motor in very slow traffic. It also makes it possible to start an engine without using a starting motor by filling selected cylinders with air, injecting fuel and applying sparks.
LG is now producing their most efficient refrigeration compressor with free piston technology. Only the coils and drive circuit would have to be changed for an automotive system that can be leak free because it is frame mounted with no hoses required. There will only be accidental leaks of refrigerants because the system can be soldered tight. I know of both a refrigerator and freezer that have worked for over fifty years without additional refrigerant.
Many ordinary alternators can be modified to supply much higher voltage at high engine speeds, and the same voltage regulation used in millions of computers can charge the battery with very high currents and power if necessary for battery drains later on.
MITI has created air-bearing lubricated turbo chargers that operate at high efficiency. This will allow small two stroke diesel engines to operate at higher efficiency. Two stroke diesel engines do not emit unburned fuel as the old gasoline ones did. In fact, direct fuel injected turbocharged gasoline engines can be highly efficient and low pollution.
Hydraulic hybrids with the Artemis system seem to allow great reductions of fuel use and energy recovery with regeneration. They will also allow the use of smaller more efficient engines.
The NOAX hydraulic transformers and motors may work as well as the Artemis electric valve system. NOAX keeps the idea of the use of their single piston diesel hydraulic engine in an automobile well hidden. It is the ultimate start-stop engine, but I don't think many single piston cars were sold after 1900.
All cars can be retrofitted with batteries that will allow almost all operation of lights and electronics to be done with home charging and limited use of the alternator. Partial regenerative braking with an alternator can then be implemented at very low cost.
Electric valves have been made for engines and they will be much improved by innovation. Gasoline engines will need no throttle valve. With additional valves, air hybrids can be invented with rapid air starting and power boost.
If much of the money and time spent on developing the Lithium Ion batteries had been spent on developing and implementing cheap manufacturing methods and equipment for ZEBRA batteries, the EV1 could have had a 300 mile range at low cost.
Much, if not all, of the cost of the EV1 car development and manufacturing was subsidized by the US taxpayer and the cars should have all been delivered to the government for further research and testing instead of being crushed. Now the taxpayer is again subsidising the people who destroyed valuable useful government paid for property. GM should have been allowed to fail so that there was a larger market for Ford and it would not have to be subsidised too.
There is no way that GM can claim that there was no market for EV1 as GM never sold any and never intended to sell any. GM had the real opportunity of making hundreds of thousands of dollars off of the sale of the vehicles instead of crushing them. GM had the cooperation of High US officials in destroying publicly supported property that sill had a high value. GM also sabotaged the car by making it an expensive sports car with limited seating and much too high power for practical use.
Air bearing electric turbochargers and air bearing exhaust gas turbo-alternators can make a small engine run like a larger one and maintain efficiency. Welded sealed organic boilers turbines and compressors and condensers can also recover additional energy.
None of the above will help as much as 55 MPH limits on motorways. ..HG..
Posted by: Henry Gibson | 21 September 2009 at 10:37 PM
I agree with HG that there was no market for the EV1 because it was an expensive sports car with limited seating and much too high in power for practical use.
And.
Was GM responsible for killing the EV by not making it?
Well then, did HG, BC, Kelly, and I build EVs? . NO.
Then we are equally guilty.
Posted by: ToppaTom | 21 September 2009 at 11:06 PM
"Well then, did HG, BC, Kelly, and I build EVs? . NO."
I was not much more than a kid when they came out. Now I and all other younger people are going to have to deal with the mess created by the oil industry for the next 50 years of my life.
I'm instead looking forward to the Nissan Leaf, I doubt there's any way big oil can kill that one. It's interesting, the more I think about it, the more I realize there is absolutely nothing big oil can do to save itself. They can't stop the EV now and once it comes out it will be a swift transition, the market will take care of everything. I wonder what they are thinking right now, do they realize that in 10 years their industry is going to be on its last breath? I guess they'll try to hang on to aviation applications and natural gas for heating. But by then, everything else will have been electrified.
Maybe they can read the writing on the wall and are planning a strategy to move into coal for electricity generation.
Posted by: Mark_BC | 21 September 2009 at 11:47 PM
It's encouraging to see the realization that the market will take care of everything.
Not quite true, though; we still need a minimum of laws (gas tax, imported oil tax, or CAFE, etc.), but thinking oil companies are some evil entities that make us choose big vehicles is scary.
Yes it is interesting; the more people think about it, the more they realize there is absolutely nothing big oil can do to stop the EV now, nor could they for the last 10 years; nor ever.
But it will be a slow transition, as electrification becomes "affordable" the market will take care of, not everything, but it will of most things.
Do not pin all your hopes on the Nissan Leaf, Volt or any other early EV – like the Insight; when the time is right, when the technology is ready . . .
Don't you wonder why some people are so afraid to admit that the public, ON THEIR OWN VOLITION, bought Hummers in great numbers, while letting the Insight die ?
I think these are the same people who want to outlaw pure battery EVs and force their private vision of utopia on everyone else.
We are safe from that - unless we undergo our own Cuban revolution.
Posted by: ToppaTom | 22 September 2009 at 05:28 AM
What will be the role of post-lithum batteries and/or future e-storage units in the affordability of future BEVs?
Will ferrous-ion batteries be more performant and cheaper than lithium-ions?
Will another, more performant, battery technology come up by 2015?
Will ultra-capacitors (ESStor?) ever become a reality and if so what will be their impact on affordable practical BEVs?
Can ultra-capacitors be effectively combined with high power baterries to supply future BEVs with the high energy and high power required at an affordable price? Newly developped DC to DC converters should help to manage those two very different e-storage units effciently.
On-board e-storage units performance have to be improved at least 5 folds (from 100 Wh/Kg to 500 Wh/Kg) and their price reduced in the same ratio (from about $1K/Kwh to less than $200/Kwh) before affordable and practical BEVs are mass produced.
Can that be done by 2015/2016 or will it be by 2020/2021?
BYD is actively working on both. Will it succeed? If so, when?
Toyota is also working of post-lithium batteries. Will it succeed by 2015/2016?
A breakthrough in on-board e-storage unit is essential to increase performance and lower cost.
Meanwhile, improved PHEVs could bridge the gap between gas guzzling ICEVs and clean BEVs and offer a progressive transition.
Posted by: HarveyD | 22 September 2009 at 07:44 AM
The evi failed because most people at the time saw a battery car and thought of the nicad trash they had bought...
It also failed because almost everyone with the money to buy them back then wasnt interested in a us made car nor were they interested in saving the world nor were they interested in anything other then themsevles.
To make matters worse remember nimh isnt all that spiffy a tech. It eats 1/3rd the energy put into it and back then the charger alone would eat anouther third BOTH when charging and again when discharging.. and it lost 105 just sitting there for more then a few hours...
This ment.. from coal to your wall.. about 30% eff.. from wall to battery about.. 70% eff half would be lost in the battery and then again only 70% would make it past the inverter and then the electric motor would eat a sizable chunk too...
So the well to wheels was abysmal.
Posted by: wintermane2000 | 22 September 2009 at 12:26 PM
Toppa Tom wrote;
"[The Insight] didn't sell. Not because of patents, or being crushed, or brain washing."
Oil was $11/barrel when it came out; even then, there were waiting lists for the vehicle. At most locations, you couldn't just walk up and buy one, you had to put a deposit down and wait some unknown number of months before your vehicle would arrive. Such a model is not meant for the typical sales volume.
"Was GM responsible for killing the EV by not making it?"
Certainly, and on top of that, they wouldn't even sell it. The even fought off people enthusiastically waving checks at them and spirited the EV-1s away to be secretly crushed in a remote desert location. Funny that 2 weeks after they bought Hummer, they killed the EV-1...
"It's encouraging to see the realization that the market will take care of everything."
As recently as 2004, GM's market share was 27.3%. Now, it stands about 19%. With GM market share down almost 30% in 5 years, it certainly has caught the attention of some there. Hopefully, enough of them...
"The Market" is often held up as an glorified icon in some quarters, though the debilitating effects of a market-based economy run wild are more than evident today (try making that claim 2 years ago). Most people have stopped worshipping "The Market" and have realized it for what it truly is.
"Don't you wonder why some people are so afraid to admit that the public, ON THEIR OWN VOLITION, bought Hummers in great numbers, while letting the Insight die?"
The Hummer was advertised to the hilt; not so for the Insight. The Hummer was mass produced; the Insight was a handcrafted automobile replaced by the Hybrid Civic, which is doing just fine these days. Now, the next generation Insight is out and selling like hotcakes in Japan. Hardly dead...
Posted by: Will S | 23 September 2009 at 09:53 AM
Actualy the hummer never sold all that well. We have likely sold more million dollar yachts then hummers.
Posted by: wintermane2000 | 23 September 2009 at 02:38 PM
By going deeper in debt, at the rate of 2 to 3 trillion $ a year, we bought $1 000 000 houses and $ 100 000 wheeled monsters we could not afford during too many years. Bankers and Wall Street Smart Operators rejoiced until mid 2008.
When the roof caved in, we the gulibles, gave those very same people another 3+ trillion $, to supposedly correct their ways, but not to change our long time acquired attitudes. We still want oversized house, oversized gas guzzling ICE monsters. Another 3 trillion $ may be required to de-program us and re-learn to live within our means.
A 6 trillion $ exercise is not that easy to do, specially when the majority doesn't want to change and still believe that free, unchecked economy and God will fix things up.
Dreamers will have to wake up and pay for it sooner or latter; before our all mighty $ is devaluated to a second rate currency.
First generation PHEVs and BEVs to not have to have 7 large seats, be able to haul a huge boat, to accellerate to 100 Km in less than 5 seconds, to have a top speed of 200+ kph, to go 500+ Km between charges etc. People with very large over-weight families could buy two smaller units and not drive over 100 kph.
No doubt that second and third generation BEVs (by 2015+ and 2020+) will have much better performance and that ...my BEV is bigger and faster than yours... attitude may relive again.
Posted by: HarveyD | 24 September 2009 at 08:41 AM