5 Technologies that Make Internal Combustion Engines Better
by Michael Graham Richard, Ottawa, Canada 
on 08. 7.08
5 Fuel-Saving Technologies
In the long run, the internal combustion engine (ICE) is on the way out and electric motors are on the way in, but ICEs have been around for so loooong that we should be careful about announcing their demise. They're going to stick around a while longer, and so it's very important to make them as efficient and clean as possible.
Car and Driver looks at 5 fuel-saving technologies that are keeping the ICE relevant (if far from ideal). As they say, they still work on basically the same principle as they ever did, but old 4-cylinder engines produced about 20 horsepower while modern ones can generate up to 250 hp while being cleaner and burning less gas. Read on for more details on the 5 fuel-saving technologies: Clean diesel, direct injection, cylinder deactivation, turbochargers, and variable valve timing and lift.
Clean Diesel
Various advances such as the availability of ultra low sulfur diesel fuel, better catalysts and particulate matter traps, better control over combustion are making diesel engines cleaner, so you can expect a new wave of diesel passenger vehicles to come to the US in the next few years.
Diesel engines are certainly far from perfect, but they have inherently better thermal efficiency than gasoline engines, and they are usually more durable (if also more expensive and heavier). Another benefit is that they can run on biodiesel, which if you can find fuel made from waste cooking oil or (in the next few years) from algae can be very green.
Direct Injection
Before direct injection, the fuel was mixed with air in the car's intake manifold. Now, with direct injection, the fuel is mixed with air inside the cylinder, allowing for better control over the amount of fuel used, and variations depending on demand (acceleration vs. cruising). This makes the engine more fuel efficient.
Cylinder Deactivation
The name says it all. ICEs with this feature can simply deactivate some cylinders when less power is required, temporarily reducing the total volume of the engine cylinders and so burning less fuel. This feature is found on V6 and V8 engines.
Turbochargers
Turbochargers increase the pressure inside cylinders, cramming more air and allowing combustion to generate more power. This doesn't make the engine more economical in itself, but since a smaller displacement engine can generate more peak power, you can more easily downsize and save there.
Variable Valve Timing and Lift
Valves open and close to allow air and fuel to enter cylinders and for the products of combustion to exit. Different valve timings produce different results (more power, better fuel economy). Traditionally, you couldn't vary that timing, so the choice had to be made once when the engine was designed. But many modern engines can vary valve timing, allowing for example the default low RPM range of the engine to have more economical timing, and the higher RPM range to go for max power. This allows a smaller displacement engine to produce more peak power, so it allows for downsizing and fuel savings.
One Big Problem With All of This
The problem is that most of the gains from these technological breakthroughs have been used to increase power instead of reducing fuel consumption. At best, fuel economy stayed the same while power increased.
Now that environmental awareness is increasing, that global warming is on everybody's mind and that oil is very expensive, we can hope that carmakers will end the horsepower arms race and finally use these technologies to truly make more efficient cars.
A Second Life for the Internal Combustion Engine
All the technologies listed above (and more, like Homogeneous Charge Compression Ignition) could be useful for longer than we think. If series plug-in hybrids like the GM Volt become popular and battery-only electric cars (or hypercapacitors) take a while to mature fully and come down in price, many cars could still have an ICE as a range-extending generator that only kicks in when the batteries are low. The more efficient and clean these are, the better.
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All these "improvements" are also something else to go wrong to cost people more money (but hey, its more work for mechanics!). Cadillac did try a V8-6-4 engine back in the 80s, I remember seeing the display in a funeral hearse. I heard that many of those engines were very unreliable.
"All these "improvements" are also something else to go wrong to cost people more money (but hey, its more work for mechanics!). "
Honda engines have many of these, and they are pretty reliable.
The cadillac variable thing was indeed a poor implementation, but things have to start somewhere. This tech is much more mature now. Like comparing a 386 with a Mac Pro, or a 1990 cell phone with a current one.
Only turbochargers have a big reliability tradeoff in that list. The rest is pretty much neutral as far as I know.
The fact that you can use a smaller capacity engine with a turbocharger bolted to it to make the same power as a large engine is not that black and white.
Boosted engines have a higher brake specific fuel consumption.
Basically, you have to add extra fuel to cool the cylinders when using a turbo which means you consume more fuel than you would of with a larger engine without a turbo to get the same power.
As long as you stay "off boost" then fine, but on boost the fuel consumption of a turbo charged engine is actually pretty bad.
ICEs. Improving them is polishing the handrails on the Titanic.
"ICEs. Improving them is polishing the handrails on the Titanic."
Yes, because NOT improving them is going to make all of them magically disappear and be replaced with unicorn-dust powered cars.
why have cars?
"why have cars?"
Personal mobility?
I mean, feel free not to have one if you don't need it. I don't have a car now, and never had one. But I can certainly understand how it has HUGE upsides, despite the also numerous downsides.
On technology that has gone unmentioned here is an engine cut off when the driver comes to a stop, yet allows the radio and cooler to keep functioning.
Here's an article about it.
"... unicorn-dust powered cars..."
Oh! Oh! Where can I get one?????
I notice that transmissions are noticeably absent from the list.
Recent 7 speed DCTs from Borg Warner and 8 speed ATs from ZF allow for optimal gearing, improved acceleration, and, in the case of the ZF, integrated start/stop technology.
DI and VVT will become common place. The jury is still out on boosted engines. Japan prefers NA, Germany preferes FI, and North America is hedgining its bets. It is true that additional fuel is needed to cool the charge but this can be avoided by using an intercooler and expansion in the immediately before intake (ala Porsche 997 GT2). If the need to cool can be avoided, and thus the higher BSFC, then turbocharging can actually become a means of waste heat recovery by running a miller cycle.
Ultimatley, running a higher number of gears in a downsized engine with VVT and DI will provide the biggest gains in fuel economy with the lowest cost. Big gains to be had in aerodynamics, reducing rolling resistance, and eliminating parasitic loads.
About stop-start and 7-speed trannies, I think they're great, but this article seems to be specifically about stuff directly in the engine that is in fairly wide use.
Stop-start isn't that widely used yet (though it should).
I know electric motors are all the rage these days but is it really a better technology? Sure electricity is cheap and petrol is the enemy but electric cars are made of some nasty things too. Batteries aren't environmentally friendly, nor is burning more coal to make up for the shift from gas to electricity. Just ask the mountain tops, more electricity doesn't solve the problem it just shifts the burden to other places. I'm no expert in the matter but why is switching from one bad solution to another bad-in-a-different-way solution better?
@ Christopher.
There are so many reasons to switch from gasoline powered cars to electric cars powered by batteries (or someday fuel cells).
1) Gasoline is a dead end. It's on the verge of running out. There's no way to make more, not even by growing fuel (the world oil consumption in calories exceeds all calories grown on earth including food by seven times). Not changing means no more cars at all.
2) Global warming. Electric cars don't produce global warming gases. Global warming is the largest environmental threat to the future of mankind.
3) Better efficiency. The internal combustion engine (ICE) is only about 20-30% efficient (depending on a lot of factors). Most of the energy is lost as waste heat. Electric engines have much higher efficiencies, 80-90% or so. And things like regenerative braking can recapture energy, something impossible with an ICE-based vehicle (excepting hybrids).
4) Recycling. Almost all the components of an electric car can be recycled. The same can't be said of the gasoline burned in ICE's.
5) Electricity from renewables. It's true that currently most electricity comes from non-renewable sources like coal and natural gas, but that's changing. The price of all fossil fuels is rising, and the cost of installing wind, solar, and other renewables is falling. 20 GW of wind was installed last year worldwide (vs 2 GW of nuclear). Solar efficiencies improve while costs fall every year. New solar and wind plants are coming online all the time.
In short, we're not replacing a bad apple with a bad orange. There are issues using electric cars, but solutions to address them are achievable through proper government policy and foreseeable techlogical advances. And starting the switch now will reduce fossil fuel usage which will ease the symptoms of the energy crisis for all of us.
Excellent comment JSD. In fact, most new chemistries of batteries are non-toxic and recyclable, and they might get replaced by hypercapacitors that have a much longer life at some point.
Many excellent points JSD
Of course, battery charging can be just as efficient as discharging. And even if the electricity comes entirely from outdated 35% efficient coal plants with 25% loss during transmission, that means about 20% efficiency overall. So even in the worst possible case (all electricity from fossil fuels, no regenerative braking) the electric car uses no more fossil fuels than an ICE might, and in any realistic situation it will do much better.
Anthony, even the worse possible case might be better than it first looks. Most coal plants don't shut down at night and off peak, so if you charge at that time, you might be using power that would be lost anyway.
Still, coal has got to go. It's still easier to clean up a few thousand coal plants than a few hundreds of millions of tailpipes.
Rather than discuss a fairy tale world where non existent technology dominates or an unrealistic paternalistic state where freedom is crushed, we need to applaud expansion of incremental technologhy that can be widely dissemenated t do a lot of good
Rather than discuss a fairy tale world where non existent technology dominates or an unrealistic paternalistic state where freedom is crushed, we need to applaud expansion of incremental technologhy that can be widely dissemenated t do a lot of good
I still have a car but now I commute to my workplace on my bicycle that I bought for $800 with all of the attachments. Thant was last year and its already paid for its self! I still have a car but I use it to go other places my bike cant. I say if you really dont need a car...dont get one!
Electric makes sense as a replacement to petroleum because the infrastructure already exists (archaic as it may be here in the U.S.) and it is easier to incrementally replace the energy source with more sustainable options.
Hydrogen fuel cells effectively require a whole new infrastructure on top of their various other issues. Even switching to 'clean' diesel engines running on plant-based fuels requires significant adjustments to our liquid fuel distribution networks.
On the other hand, electricity is electricity. Turning new wind an solar installments on while turning coal plants off can be done without major supply chain headaches—in fact, electricity customers generally would be completely unaware of any change to the source of their energy outside of green marketing. Satisfied customers makes for a smoother transition.
Just my 2¢.
"... unicorn-dust powered cars..."
But wouldn't that cause complete unicorn-dust depletion by 2050??
"If series plug-in hybrids like the GM Volt become popular..."
Does anyone else feel a tinge of anxiety every time the GM Volt is refered to on this website?
Is anyone else disgusted by a GM business plan built on Leasing the battery for the Volt to consumers?
To be fair, with the state of our electrical grid in the US, we'd need a whole new infrastructure to support electric cars.
And for us folks in the city who don't have off-street parking, electric cars and plug-in hybrids aren't viable. We can't be running extension cords up and down our blocks to charge our cars. So improving the ICE is pretty important to me.
"... unicorn-dust powered cars..."
"But wouldn't that cause complete unicorn-dust depletion by 2050??"
I understand it's pretty hard to find already...
Icelander, I agree with you. We can make ICEs better and more efficient. Ok, I give in that if you are running high boost pressures and have a lead foot you will not do very well on gas, but that is the same with any car.
Plus one thing people don't think about when talking about how hot the charge is..... water injection. It cools the engine, cleans the engine, and does not add any pollutants.
This is a great topic. I have been reading about the development of the ICE and found it interesting the early engines, up until EFI, were long stroke and had quite efficient combustion. The down side was that they were slow off the line. With the desire to have faster 0-60s, compression became higher and the stroke shortened. While these are certainly not the only changes, it has been suggested that a return to longer stroke engines could be made, and greater fuel efficiency sustained.
Personally, I would like to see more hydraulic hybrids, like those being piloted by UPS and Ford. They store energy in hydraulic systems, which are great for stop/start driving. I read a great piece called "Hybrid Hummer Hums" at http://economicefficiency.blogspot.com/2008/07/hybrid-hummer-hums.html It has some great backers like Siemens and Eaton Corporation.
Of course, all of these technologies have been around for a very very long time. Nothing here is new.
European and Japanese cars have had all of this and more for 20+ years.
-Dan
Hey everyone!
I think turbos are one of the best improvements available to ICEs. The specific bhp fuel use number is an nissue, but not the most important one. Sure, turbos tend to be used in sports cars to make them perform better (WRX, 911, Evo) but the most significant use of turbos is in family cars (SAAB 9000, 9-5). That is where huge gains can be made, while keeping dad happy at the throttle! Volvo is another pioneer of turboed family saloons and estates that really provide grins inbetween family duties.
MICHAEL...STOP PERPETUATING A MYTH.
How many times do I have to post here about the incompatibility of biodiesel and the new T2B5 diesels? I swear, its shocking how blithely you lot go on about using biodiesel in the new diesels. Just look under the fuel filler door of the new Audis, BMWs, VWs, and all the others that are already out in EU and coming here shortly. What will you see???
NO BIODIESEL
Will they be able to run for a time on biodiesel? Sure. Will you screw up the very complicated emissions systems after a time? Sure. Will you get warranty coverage for that very expensive damage? Good luck with that.
Sheesh!
--
MGR: Willy, nobody knows everything. Instead of acting outraged, please share your sources and I'll check them out. I haven't seen anything about 'clean diesels' not being able to run on biodiesel, and if it's the case, I'd like to know more.
Don't forget something completely fundamental about ICE's: The fewer the cylinders, the lower the internal friction. This has a massive effect on gas mileage and the upper RPM range. With a low number of cylinders, you can crank up the RPM's and shrink the mass to equal the same horsepower. The 1300cc 4 cylinder Hayabusa puts out about 170HP. That is a TINY engine. 170HP is a lot of power for a fuel efficient vehicle.
The automotive industry could learn a lot from the motorcycle industry.
"In the long run, the internal combustion engine (ICE) is on the way out and electric motors are on the way in, but ICEs have been around for so loooong that we should be careful about announcing their demise. "
I LOVE this outlook. The entire automotive industry was built on fossil-fueled ICE's. It's BY FAR the most portable and versatile source of energy known to exist. While I don't disagree that major changes appear to be in the offing, to casually announce that ICE's are "on the way out" sounds a lot like the unicorn dust referred to earlier.
Speaking of which, If I hear one more time of the magical battery enhancements that we're supposed to be on the verge of, I may just vomit. Everybody assumes that the ICE is going away, and that revolutionary batteries will appear any second, as if just wishing it so can make it happen.
I'll believe either one when I see them. Until then, they're both unicorn dust.
"Don't forget something completely fundamental about ICE's: The fewer the cylinders, the lower the internal friction. This has a massive effect on gas mileage and the upper RPM range. With a low number of cylinders, you can crank up the RPM's and shrink the mass to equal the same horsepower. The 1300cc 4 cylinder Hayabusa puts out about 170HP. That is a TINY engine. 170HP is a lot of power for a fuel efficient vehicle.
The automotive industry could learn a lot from the motorcycle industry."
A 1300 ccHayabusa runs at much higher RPM than a 2000cc Honda Civic does, and friction increases at a non-linear rate so it's not just a matter of low cylinder count. The Hayabusa also has much higher compression ratio as well, which requires a higher octane fuel. Nobody argues much when you claim a Honda Civic will go 100k miles with only an oil change, and nobody argues when you claim they can go 200k miles with routine maintenance. Can the more highly stressed Hayabusa do that?
I've often wondered and posted here that Suzuki and Honda with 600cc motorcycle engines that are well proven and in production may have an advantage with a series hybrid since the ICE would only have to produce slightly more than the average power required. A 600cc motorcycle engine at half power might be more than sufficient.
My sources are:
VWOA
AUDI
BMW
Daimler
Simply call any of their customer service centers and ask. Or go to a dealership and ask. Or take a trip to EU and look. I have done all three.
All of the VW, AUDI, Mercedes enthusiast forums have been talking about this for 2 years now. Jalopnik has been talking about it for 2 years. Why do I have to give you exact sources for something that is almost difficult to miss? This is why I come off as so exasperated with this misinformation.
I unsubscribed a while ago (when one of the writers tried to justify why he bought a SUV), however I just stumbled upon this article via Digg and I think you forgot one technology: the six-stroke engine.
I won't detail it here, but I urge you to see the wikipedia article on the matter, it's very interesting and I can't understand why it's not already in our production cars.
Nevertheless, I agree with everybody regarding the electric car: it's the way to go. I ride an electric motorcycle for my everyday commute since March 2007, and it's perfect.
Great comment JSD.. We should all be taking a look into the future.
Hydrogen fuel cell vehicles are in fact electric vehicles. Switch the fuel cells for a small ICE and you have a serial hybrid. If fuel cells are the future, then we need years of development with hybrids to prepare the way for the engineers to sort out the accessories as well as the drive system. I'm old enough to remember that most people were nervous about the new fangled electric windows and power steering. When Honda introduced V-tec for motorcycles, the press lamented the increase in complexity and predicted shortened engine life. GM's problem has been that it is run by bean counters and not engineers. Break up the monopolies and watch for a boom in new tech.
Why dont you ever mention the Compressed Air Technology?
They are already making commercial production of cars, and they are not expensive.
Just browse Google, and you will find.
I'm not sure I agree with cylinder deactivation being listed here. After all, you state right there that it's used in V6 and V8 engines - and IMO there is NO justification for those being used in passenger cars anyway. No ordinary car needs more than a 2-litre 4-cyl or thereabouts. Moving up to pickups/light trucks, most of those would be more than adequate with a four-cylinder turbodiesel of some sort. After that, you're getting into serious commercial vehicles, which will have bigger diesel engines, but I've not really heard of cylinder deactivation being used in diesels anyway.
It seems to be mostly a way of making ridiculously massive SUVs slightly less wasteful. Which IMO is rather like polishing a turd...
Why not focus on the development of better hybrid cars. It would be much worth the time and effort than trying to improve the ICE which really consumes more fuel than hybrid ones.
Yeah, except hybrid cars still use an ICE, so improving ICEs would also make hybrid cars more efficient.
What's with the constant "forget about [technology x]! MY pet technology is much better and we should ignore all others" especially in the context of vehicles...? We need ALL technological improvements *and* better public transport *and* alternative fuels we can get.
There was no mention of a new technology (well new to the market anyway) coming from a company called Turbine Truck Engines...30% more efficient, 30% less emission and can run on any fuel type (gas, diesel, hydrogen, etc...)
www.ttengines.com
I'm surprised in the research done for this article that treehugger didn't come up with this technology.
Cheers,
An electric motor is a simple device which consists of one moving part which is turned by electromagnetic induction. An electric vehicle (EV) is one which is powered by electricity, rather than fuel combustion, which powers conventional vehicles which use ICEs (Internal Combustion Engines). Most electric vehicles are powered by conventional DC electric motors, while some locomotives are magnetically levitated. Electric motors have many advantages over gasoline and diesel powered engines, gasoline engines are 20-25% efficient, while electric motors are 80-99% efficient, meaning that they convert 90% of the electrical energy consumed into mechanical energy. Electric motors are quieter, safer, more reliable, and more cost effective than gasoline powered engines. Since electric motors are powered by electricity, their power can come from a wide variety of power sources, such as batteries, fuel cells, and batteries can be charged with wind power, solar power, hydroelectric power, geothermal power, biofuel powered generators, and other sources. Electric vehicles' motors do not idle, so they don't waste electricity when idle, except for car electronics, such as radios and air conditioners/heaters. Regenerative braking is possible, meaning that when you release the acceleration pedal of your electric vehicle, it will use the kinetic energy (energy that it possesses due to it's motion) that it possesses due to it's intertia (resistance to a change in velocity) to turn the electric motor which will generate electricity and recharge the batteries. If you charge them overnight, and every night, range should not be an issue unless you drive extremely long distances, but it shouldn't be too difficult to charge them. ICE's are becoming increasingly complicated, expensive, and there are many signs proving that they have to be replaced ASAP, that technology is no good.
Electric motors do not require the following:
- Transmissions.
- Cooling systems.
- Oil changes.
- Firewalls.
- Gasoline/Diesel.
- Overhauls.
- Maintenance.
- Exhaust.
Robert Anderson: "ICEs. Improving them is polishing the handrails on the Titanic.". That is right. :)
Source: http://www.kompulsa.com/kae/vehsalt.php#ev