Navigant Research Blog

Automakers Go for MPG Records

— July 10, 2014

Automakers have had some poor publicity recently, with safety recalls and financial penalties imposed for exaggerating fuel efficiency performance.  In the United States, Ford was forced to apologize and offer customers compensation when its vehicles did not deliver the promised number of miles per gallon.  Honda and Hyundai suffered a similar fate in 2012 in the United States, and Hyundai and Ssangyong have also recently incurred the wrath of legislators in their home country of South Korea.

Fuel economy has risen to the top of the list of factors that influence new car purchases, even in North America, where historically cheaper fuel has made miles per gallon a low priority for consumers, until recently.  Thus, many manufacturers have shifted their marketing emphasis from 0-to-60 miles per hour (mph) times to average miles per gallon (mpg) under standardized testing.

Taking the Long Way

The big problem with standardized tests is they don’t represent anyone’s actual driving, so the prospect of achieving the stated figures is unlikely.   Most people have bad driving habits (from a fuel economy perspective), such as hard acceleration and braking, driving with under-inflated tires, and carrying excess weight around without realizing that all of these factors affect how much fuel is used.   Others make it their life’s work to squeeze the most miles from a gallon of fuel, and there are competitions for those who want to be the best.

Mercedes periodically attempts long-distance driving feats with its production cars.  In July 2005, three standard Mercedes-Benz E 320 CDI cars drove from Laredo, Texas on the Mexican border to Tallahassee, Florida, covering 1,039 miles on a single tank (80 liters/21.1 gallons) of fuel.  This was part of Daimler’s introduction of diesel vehicles to the U.S. market.  In 2012, a Volkswagen Passat TDI made it 1,626 miles from Houston, Texas to Sterling, Virginia, again on a single tank of fuel.

Out of Africa

Now, a Mercedes-Benz E 300 BlueTEC HYBRID has driven the 1,223 miles from Tangier, in Northern Africa, to the United Kingdom in 27 hours, arriving at the Goodwood Festival of Speed with an estimated 100 miles of range still available.  The BlueTEC averaged 73.6 mpg on the journey.  This type of demonstration shows what can be accomplished in a production vehicle in driving conditions that included heavy rain, intense heat, rush hour traffic jams, and significant elevation changes.

This sort of feat is one of the biggest challenges facing electric vehicle sales.  Although few people would actually want to tackle a journey of over 1,000 miles on a single tank of fuel, many people are happy that their vehicles can do that, just in case.  And few would want to undertake such a journey where they have to stop every 100 miles to recharge for a couple of hours, even if there was a network of charging stations in place.


Hybrid Race Cars Dominate the Le Mans 24-Hour Race, Again

— July 6, 2014

The annual 24-hour endurance race at the Le Mans circuit is famous for presenting both car and driver with a grueling challenge.  The goal is quite simple – teams of drivers and mechanics battle to see who can complete the most laps of the circuit in 24 hours of driving.  The Fédération Internationale de l’Automobile (FIA) organizers set rules for the vehicles taking part, such as minimum weight and limitations on the use of four-wheel drive, so it’s not simply a case of developing the most powerful engine.

In this month’s 82nd running of the race, Audi secured its 12th victory in 14 years with a one-two finish.  The Audi team’s No. 2 car finished with 379 laps, three more than its No. 1 team, and Toyota took third place.  The winning team overcame turbocharger problems for its third success in the world’s most famous endurance race, watched by 263,000 spectators – the highest attendance in 20 years.  The  Porsche team was in second place overall with its new vehicle when it was forced to retire in the 22nd hour with technical issues.

Full Day’s Drive

The race is won by a combination of performance and reliability, and the winners had to replace key engine components, such as the fuel injector and turbocharger, along the way.  With speeds exceeding 200 mph along the straights, the Le Mans race gives auto manufacturers an extreme testing ground for the technology that often ends up in production vehicles.  With a lap distance of just under 8.5 miles, the winning car traveled just over 3,200 miles in 24 hours.

This year, Audi, Toyota, and Porsche all raced different variants of hybrid drive:

  • The Audi R18 e-tron quattro couples a mid-mounted 3.7-liter V6 turbo diesel injection engine powering the rear wheels with a hybrid system on the front axle, which uses a flywheel energy storage system.  The 2014 model features an electric motor linked to the engine’s turbocharger that converts thermal energy from the exhaust gas into electric energy.
  • The Toyota TS040 HYBRID also features a four-wheel drive hybrid boost system for the 3.7-liter V8 gasoline engine.  Toyota Racing is using an Aisin AW motor-generator on the front axle to complement the DENSO unit on the rear.  Under deceleration, the motor-generators apply braking force in combination with traditional mechanical brakes to harvest energy, which is transferred via inverters to store in a bank of ultracapacitors.  During acceleration, the stored energy delivers a power boost as required at each axle.
  • Porsche’s 919 Hybrid drive system is based on a 2.0-liter V4 gasoline engine.  The engine is a structural component of the chassis and features direct injection, a single turbocharger, and thermodynamic energy recovery capabilities.  Two different energy recovery systems charge the lithium ion battery pack used for energy storage.  One is the recovery of thermal energy by an electric generator powered by exhaust gases.  The second hybrid system is a motor on the front axle using regenerative braking to convert kinetic energy into electric energy.

It’s fascinating to see major manufacturers testing their hybrid technology under race conditions.  In 2012, Peugeot, which won Le Mans in 2009 with a diesel hybrid race car, had to withdraw funding for its team.  Motor racing is an expensive sport.  But lessons learned by all participants about thermal energy recovery, lightweight vehicle structures, and the relative performance of gasoline V4, gasoline V8, and diesel V6, as well as the different energy storage options, can deliver valuable benefits when translated into production vehicles.


Tesla Looks to Fuel a Battery Revolution

— June 18, 2014

Elon Musk, CEO of Tesla Motors, stunned the automotive world with his announcement that he was making all his company’s electric vehicle (EV) patents open source.  “Tesla will not initiate patent lawsuits against anyone who, in good faith, wants to use our technology,” he said on his blog.  Musk explained that he decided to do this because the “world would all benefit from a common, rapidly-evolving technology platform.”

Automotive companies are well-known for developing proprietary solutions for almost anything in an effort to get one step ahead of the competition, even for a short time.  But this approach means that often the opportunity to share in the rapid growth of a new technology is lost, and suppliers can miss out on the potential for much higher volumes.  Some have speculated that this change in attitude to patents is a move to create bigger demand for battery cells from Tesla’s planned Gigafactory.

Weight and Range

Conventionally powered vehicles are still the main business of all major automakers, which are continually investing in new ways to make these vehicles more efficient.  One of the current trends is to develop stop-start technology to capture some of the efficiency gains of a full hybrid at a fraction of the cost premium.  Full details on the latest developments are discussed in Navigant Research’s 48 Volt Systems for Stop-Start Vehicles and Micro Hybrids report.

When designing an electric or electrically assisted powertrain, manufacturers have to weigh a number of characteristics for each particular model.  Not all hybrid vehicles and EVs are optimized for economy.  Some use the stored energy to boost power or drive an additional pair of wheels.  Bigger batteries cost more and also add weight and take up space, but they provide greater electric-only range.  Small, light vehicles can travel further per kilowatt-hour of battery capacity than larger, heavier vehicles.  These compromises are difficult to resolve, and battery manufacturers have a role to play.

Step Up

Anticipated sales of battery electric vehicles (BEVs) are projected to be large enough to lead the demand for lithium ion (Li-ion) batteries in the automotive world.  Even though sales numbers of hybrid electric vehicles (HEVs) dwarf those of plug-in hybrid electric vehicles (PHEVs) and BEVs, a much larger battery capacity means that at least 60% of the Li-ion batteries made for automotive use will end up in a BEV over the next couple of years.  That percentage will increase slowly until the end of this decade, after which stop-start vehicles will begin to influence the distribution.  Maybe this move from Tesla will be an incentive for the established carmakers to put more effort into their BEV product range.

Navigant Research expects that the overall market for vehicle Li-ion battery revenue will reach $26 billion by 2023, and that revenue could exceed that if newly emerging 48V micro hybrid technology delivers on its promise of fuel efficiency at a low-cost increment, and a significant number of original equipment manufacturers choose to implement it with Li-ion battery packs.  In addition, the expected steady lowering of per-kilowatt-hour cost will encourage the market if manufacturers pass the savings on to customers.  Full details of the automotive market for Li-ion batteries are covered in Navigant Research’s report, Electric Vehicle Batteries.


Europe Overtaking United States in Autonomous Vehicles

— June 2, 2014

In the last few years, as the technology to make self-driving vehicles has neared production-readiness, vehicle manufacturers have begun to press legislators to ensure that the technology will be legal to use on the road when the cars go on sale.  In some countries, anything is legal unless it’s specifically banned, but in others everything is illegal unless it is specifically allowed.  One of the major pieces of legislation that concerns automakers globally is Article 8 of the 1968 United Nations (UN) Convention on Road Traffic (also known as the Vienna Convention on Road Traffic), which stipulates: “Every driver shall at all times be able to control his vehicle or to guide his animals.”

An amendment to this statement, agreed to in March by the UN Working Party on Road Traffic Safety, would allow a car to drive itself as long as the system “can be overridden or switched off by the driver.”  This, of course, means that a driver must be present and able to take the wheel at any time, so it does not open the door to fully autonomous vehicles on public roads.  Provided the amendment clears the usual bureaucratic hurdles, all 72 countries that are party to the convention will then have to work the new rules into their laws.  The convention covers European countries, Mexico, Chile, Brazil, and Russia, although it does not cover the United States, Japan, or China.

Wake Up and Drive

The big benefit of this agreement is that the European carmakers can continue to develop and introduce more advanced driver assistance systems, such as lane keeping, motorway cruising, and traffic jam mode.  Many of these systems have been under testing for a few years and are now allowed on public roads under specific licenses from local authorities, such as described in my recent blog on Google cars.  But these self-driving functions have been held back from production by the requirement that the driver must be in control at all times.  So it now looks likely that European customers will be able to order these and more advanced systems much sooner than people in Japan, China, and especially North America, where litigation is a way of life.

The automotive manufacturers are working hard to develop suitable protocols for handing back control to a driver who may not be paying attention.  While allowing technology to take over routine driving tasks is likely to improve safety, especially on long journeys, the nature of the systems will lead inevitably lead to drivers falling asleep or focusing on other tasks such as email or reading.  If an automated driving system encounters a set of circumstances beyond its capability, it will need to return control to the driver immediately.  If the driver is unprepared, this could have serious consequences.

There is still a long way to go before bringing fully autonomous vehicles to the road is practical.  The long-term societal benefits mean that it is not a question of if, but of when.  This change to the Vienna Convention is a small but very significant event, and it surprising that there has not been more media coverage of the announcement.


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