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Exclusive: Carmakers forced back to bigger engines in new emissions era
By Laurence Frost and Agnieszka Flak PARIS PARIS Tougher European car emissions tests being introduced in the wake of the Volkswagen (VOWG_p.DE) scandal are about to bring surprising consequences: bigger engines.
Carmakers that have spent a decade shrinking engine capacities to meet emissions goals are now being forced into a costly U-turn, industry sources said, as more realistic on-the-road testing exposes deep flaws in their smallest motors.
Renault, General Motors and VW are preparing to enlarge or scrap some of their best-selling small car engines over the next three years, the people said. Other manufacturers are expected to follow, with both diesels and gasolines affected.
The reversal makes it even harder to meet carbon dioxide (CO2) targets and will challenge development budgets already stretched by a rush into electric cars and hybrids.
"The techniques we've used to reduce engine capacities will no longer allow us to meet emissions standards," said Alain Raposo, head of powertrain at the Renault-Nissan alliance.
"We're reaching the limits of downsizing," he said at the Paris auto show, which ends on Saturday. Renault, VW and GM's Opel all declined to comment on specific engine plans.
For years, carmakers kept pace with European Union CO2 goals by shrinking engine capacities, while adding turbo chargers to make up lost power. Three-cylinder motors below one liter have become common in cars up to VW Golf-sized compacts; some Fiat models run on twin-cylinders.
These mini-motors sailed through official lab tests conducted - until now - on rollers at unrealistically moderate temperatures and speeds. Carmakers, regulators and green groups knew that real-world CO2 and nitrogen oxide (NOx) emissions were much higher, but the discrepancy remained unresolved.
All that is about to change. Starting next year, new models will be subjected to realistic on-the-road testing for NOx, with all cars required to comply by 2019. Fuel consumption and CO2 will follow two years later under a new global test standard.
Independent testing in the wake of VW's exposure last year as a U.S. diesel emissions cheat has shed more light on the scale of the problem facing automakers.
Carmakers' smallest European engines, when driven at higher loads than current tests allow, far exceed legal emissions levels. Heat from the souped-up turbos generates diesel NOx up to 15 times over the limit; gasoline equivalents lose fuel-efficiency and spew fine particles and carbon monoxide.
"They might be doing OK in the current European test cycle, but in the real world they are not performing," said Pavan Potluri, an analyst with influential forecaster IHS Automotive.
"So there's actually a bit of 'upsizing' going on, particularly in diesel."
IN RETREAT
Carmakers have kept understandably quiet about the scale of the problem or how they plan to address it. But industry sources shared details of a retreat already underway.
GM will not replace its current 1.2-litre diesel when the engines are updated on a new architecture arriving in 2019, people with knowledge of the matter said. The smallest engine in the range will be 25-30 percent bigger.
VW is replacing its 1.4 liter three-cylinder diesel with a four-cylinder 1.6 for cars like the Polo, they said, while Renault is planning a near-10 percent enlargement to its 1.6 liter R9M diesel, which had replaced a 1.9-litre model in 2011.
In real-driving conditions, the French carmaker's 0.9-litre gasoline H4Bt injects excess fuel to prevent overheating, resulting in high emissions of unburned hydrocarbons, fine particles and carbon monoxide.
Cleaning that up with exhaust technology would be too expensive, sources say, so the three-cylinder will be dropped for a larger successor developing more torque at lower regimes to stay cool.
The turnaround on size is a European phenomenon, coinciding with diesel's sharp decline in smaller cars. Larger engines prevalent in North America, China and emerging markets still have room to improve real emissions by shrinking.
INEVITABLE RECKONING
Fiat, Renault and Opel have the worst real NOx emissions among the newest "Euro 6" diesels, according to test data from several countries. They now "face the biggest burden" of compliance costs, brokerage Evercore ISI warned last month.
Such reckonings are the inevitable result of on-the-road testing, said Thomas Weber, head of research and development at Mercedes DAIGn_.DE, which has nothing below four cylinders.
"It becomes apparent that a small engine is not an advantage," Weber told Reuters. "That's why we didn't jump on the three-cylinder engine trend."
The tougher tests may kill diesel engines smaller than 1.5 liters and gasolines below about 1.2, analysts predict. That in turn increases the challenge of meeting CO2 goals, adding urgency to the scramble for electric cars and hybrids.
VW has been far more vocal about ambitious plans announced in June to sell 2-3 million electric cars annually by 2025 - about a quarter of its current vehicle production.
"You can't downsize beyond a certain point, so the focus is shifting to a combination of solutions," said Sudeep Kaippalli, a Frost & Sullivan analyst who predicts a hybrids surge.
In future, he said, "downsizing will mean you take a smaller engine and add an electric motor to it".
(Additional reporting by Gilles Guillaume, Edward Taylor and Paul Lienert; Editing by Pravin Char)
The turnaround on size is a European phenomenon, coinciding with diesel's sharp decline in smaller cars. Larger engines prevalent in North America, China and emerging markets still have room to improve real emissions by shrinking.
Toyota may have struck the right formula with gasoline-electric hybrids after all...
Quite true but having sat on their laurels they now seem to be behind the game. At the lower end Hyundai is offering alternatives to the Prius and at the top end Porsche's Panamera shows the way.
It all depends on the use type. The current generation of engines all operated on the fact that if you dump a big heavy cubic engine for a small tiny FI engine, MPG can be inflated. However as with anything there isnt a one size fit alls scenario. If your consistently pedalling an FI engine MPGs will drop. They need to be in their sweet spot to achieve their so called gains. For incity electric is probably the only way to increase MPGs. Out on the highway a FI or NA motor is the necessary
For years, while the Americans were lowering many different types of emissions (including oxides of nitrogen NOx), the Europeans were chasing ever-lower fuel consumption by lowering CO2 emissions limits but not other types of emissions (only very recently, with Euro 6 standards, starting to lower NOx emissions). So the Europeans encouraged diesels to lower fuel consumption and lower CO2 emissions. Lowering fuel consumption became an obsession.
The abnormally-optimistic European fuel consumption testing cycle did not help matters. So we see large, full-size luxury sedans being powered by forced-induction (turbocharged or twin super- and turbocharged) 4-cylinder engines, yet we all know that a 4-cylinder is not powerful enough for such large cars and will be constantly under boost. Larger, more powerful engines powering these big, heavy cars will be under less stress and strain, and will probably (ironically) consume less fuel.
Other tricks to lower fuel consumption include lean-burn (less fuel than normal) engines. But lean burn engines run very hot, which increases NOx emissions. At startup, and to cool things down, engines run rich (more fuel than otherwise necessary for efficient combustion). Running rich gives us incomplete combustion, which gives us soot (particulate emissions) and carbon monoxide (CO) emissions. So we need exhaust after-treatments. And you thought that slapping a turbocharger on an engine is easy!
A well-designed hybrid drivetrain is an excellent choice to lower fuel consumption. The electric motor is most efficient and most powerful at low RPM, while the gasoline engine is most efficient and most powerful at higher RPM. And that electric motor can act as both a source of power and a generator of electrical power. At slow speeds, run on the electric motor; at higher speeds, run on the gasoline engine and when coasting or slowing down, recoup some of the otherwise wasted energy to recharge the battery.
But it is not that easy to design a good hybrid drivetrain. Simply replacing the torque converter on an automatic transmission with an electric motor is simple but not the most effective, yet it is how most automakers do it, including Hyundai, BMW, Mercedes-Benz, Porsche and now Nissan (after giving up the licensed Toyota hybrid system). The best (most efficient) hybrid systems come from Toyota, Ford and now Chevy. The problem with Toyota's hybrid system is that Toyota is stubborn about not using higher-capacity lithium-ion batteries, which all other automakers are now using.
For years, while the Americans were lowering many different types of emissions (including oxides of nitrogen NOx), the Europeans were chasing ever-lower fuel consumption by lowering CO2 emissions limits but not other types of emissions (only very recently, with Euro 6 standards, starting to lower NOx emissions). So the Europeans encouraged diesels to lower fuel consumption and lower CO2 emissions. Lowering fuel consumption became an obsession.
The abnormally-optimistic European fuel consumption testing cycle did not help matters. So we see large, full-size luxury sedans being powered by forced-induction (turbocharged or twin super- and turbocharged) 4-cylinder engines, yet we all know that a 4-cylinder is not powerful enough for such large cars and will be constantly under boost. Larger, more powerful engines powering these big, heavy cars will be under less stress and strain, and will probably (ironically) consume less fuel.
Other tricks to lower fuel consumption include lean-burn (less fuel than normal) engines. But lean burn engines run very hot, which increases NOx emissions. At startup, and to cool things down, engines run rich (more fuel than otherwise necessary for efficient combustion). Running rich gives us incomplete combustion, which gives us soot (particulate emissions) and carbon monoxide (CO) emissions. So we need exhaust after-treatments. And you thought that slapping a turbocharger on an engine is easy!
A well-designed hybrid drivetrain is an excellent choice to lower fuel consumption. The electric motor is most efficient and most powerful at low RPM, while the gasoline engine is most efficient and most powerful at higher RPM. And that electric motor can act as both a source of power and a generator of electrical power. At slow speeds, run on the electric motor; at higher speeds, run on the gasoline engine and when coasting or slowing down, recoup some of the otherwise wasted energy to recharge the battery.
But it is not that easy to design a good hybrid drivetrain. Simply replacing the torque converter on an automatic transmission with an electric motor is simple but not the most effective, yet it is how most automakers do it, including Hyundai, BMW, Mercedes-Benz, Porsche and now Nissan (after giving up the licensed Toyota hybrid system). The best (most efficient) hybrid systems come from Toyota, Ford and now Chevy. The problem with Toyota's hybrid system is that Toyota is stubborn about not using higher-capacity lithium-ion batteries, which all other automakers are now using.
Useful and insightful perspective. Toyota and Lexus seem to be abdicating the segment where people wish for performance with hybrids, resting instead on existing technology and concentrating on SUVs. Hardly any exciting news coming out from them nowadays.
...
The best (most efficient) hybrid systems come from Toyota, Ford and now Chevy. The problem with Toyota's hybrid system is that Toyota is stubborn about not using higher-capacity lithium-ion batteries, which all other automakers are now using.
I also hope Toyota comes to their senses and redesigns hybrids in a modular way to swap the position - such that the significantly denser lithium ion batteries lie under the rear seats for a lower center of gravity to minimize body roll & weight transfer to the outside wheels to maximize grip, while the lighter albeit smaller capacity fuel tank lies under the trunk, and if the trunk is rather small [like overseas IS300h Hybrids], then they can omit the spare tire altogether for an aerosol can of tire repair kit so that run-flat tires don't have to be used.
This type of design would also give Toyota the option of making the under the trunk fuel tank smaller in capacity, to allow room to simultaneously fit a space saving spare tire under the trunk as well.
Back in the 1980's, rear wheel drive sedans used to have both the fuel tank, and a full size spare tire simultaneously mounted under the rear trunk.
I also hope Toyota comes to their senses and redesigns hybrids in a modular way to swap the position - such that the significantly denser lithium ion batteries lie under the rear seats for a lower center of gravity to minimize body roll & weight transfer to the outside wheels to maximize grip, while the lighter albeit smaller capacity fuel tank lies under the trunk, and if the trunk is rather small [like overseas IS300h Hybrids], then they can omit the spare tire altogether for an aerosol can of tire repair kit so that run-flat tires don't have to be used.
This type of design would also give Toyota the option of making the under the trunk fuel tank smaller in capacity, to allow room to simultaneously fit a space saving spare tire under the trunk as well.
Back in the 1980's, rear wheel drive sedans used to have both the fuel tank, and a full size spare tire simultaneously mounted under the rear trunk.
Toyota already places the hybrid battery under the rear seat in its newer hybrid vehicles. And if it means giving up the spare tire, I do not want the fuel tank in its place, for safety reasons. I guess you do not remember the Pinto?
Toyota already places the hybrid battery under the rear seat in its newer hybrid vehicles. And if it means giving up the spare tire, I do not want the fuel tank in its place, for safety reasons. I guess you do not remember the Pinto?
Interesting.
They have squeezed a tiny battery pack on top of the fuel tank under the rear seats.
But still, I'm worried such a design results in such a tiny battery pack, no wonder the overseas IS300h I tested runs flat very quickly, and has the 2.5L four cylinder ICE taking over very quickly too.
Off the top of my head, I suspect they should use the entire sub-rear seat space to house the very dense and heavy big battery pack for a really low center of gravity, and have a much smaller fuel tank positioned behind the rear seat, but above the rear axle and still allowing the rear seat backrests to fold forwards, leaving space for a space saving spare tire in the rear overhang as a crumple zone.
Thus, these plug-in hybrids PHEV's are using less ICE, and much bigger batteries and bigger electric motors, as we transition to full blown electric vehicles.
The ICE and its accompanying tiny fuel tank is almost just a gasoline power generator like in the Chevvy Volt.
^ You can also put the gas tank under the front seats, that's where it is on a Honda Fit.
The fuel tank can be placed under the front seat, as in the Honda Jazz/Fit/HR-V, or under the floor, as in the Toyota/Scion iQ.
But placing the tank any place other than the usual place of under the rear seat would involve big changes to the platform, meaning such a car would be expensive, unless the automaker intends to have a full lineup of such vehicles to share the costs of the midship fuel tank platform.
Originally Posted by peteharvey
Interesting.
They have squeezed a tiny battery pack on top of the fuel tank under the rear seats.
But still, I'm worried such a design results in such a tiny battery pack, no wonder the overseas IS300h I tested runs flat very quickly, and has the 2.5L four cylinder ICE taking over very quickly too.
Off the top of my head, I suspect they should use the entire sub-rear seat space to house the very dense and heavy big battery pack for a really low center of gravity, and have a much smaller fuel tank positioned behind the rear seat, but above the rear axle and still allowing the rear seat backrests to fold forwards, leaving space for a space saving spare tire in the rear overhang as a crumple zone.
Thus, these plug-in hybrids PHEV's are using less ICE, and much bigger batteries and bigger electric motors, as we transition to full blown electric vehicles.
The ICE and its accompanying tiny fuel tank is almost just a gasoline power generator like in the Chevvy Volt.
Designing an effective and efficient hybrid vehicle is an act of balancing 2 different drivetrains, the normal internal combustion engine and the electric drive motor(s) and battery.
Giving the hybrid car a battery of too little or too much capacity will have negative effects on fuel consumption.
A battery that is too small means that it can only drive a very short distance and only at very slow speeds before the battery discharges; the engine will be spending a lot of time driving the vehicle and re-charging the battery. If the engine is forced to run for long periods of time, even when idling, that defeats the purpose of a clean hybrid vehicle. Why not remove the electric-drive portion and just leave the idle-stop system?
A battery that is too large means that normal coasting and braking will not be enough to fully charge the battery; the engine will have to run for longer periods to keep the battery charged. If the engine is forced to run even when idling, that defeats the purpose of a clean hybrid vehicle.
So why not increase battery capacity more and make it a plug-in hybrid vehicle? But it takes a lot of battery to give a plug-in hybrid more than a few miles of range. The Chevy Volt has a range of about 80km / 50miles, but it has a HUGE battery that takes up a lot of space in the passenger cabin. The Prius Prime will have a range of about 40km / 25 miles with a battery that takes up a fair bit of cargo space; but it draws criticism from people who say that it does not have enough electric-only range.
This is why Toyota is holding off on more plug-in and battery-electric vehicles, because the current state of battery technology is not far enough along to make a battery with enough capacity that is small enough not to be too intrusive, but also be able to re-charge quickly (in a few minutes rather than a few hours).
I have no doubt that Toyota's under-seat hybrid battery has about the same capacity that its behind-the-seat battery did, i.e. Toyota has been able to shrink battery size down somewhat while retaining capacity but it is still not enough to give a reliable electric car the same range as an equal-size internal combustion-engined car.
10-25-16, 02:40 PM
So we're back to slightly bigger cubic capacity, with an electric motor...
