- Posted on Thursday, September 20th, 2007 at 1:46 pm
Introducing HCCI Technology
By Susan Garavaglia
External Communications Manager
Recently, GM demonstrated a fuel-saving engine technology that I think has real potential to reduce our nation’s dependence on oil.
It’s called HCCI, which is shorthand for Homogeneous Charge Compression Ignition engine, and we think it will improve fuel economy, when combined with other advanced fuel savings technologies, by about 15 percent.
With HCCI, a variety of advanced engine technologies combine to allow for lower temperature fuel burning, which is more complete and more efficient and cuts vehicle emissions. It also cuts the amount of heat energy that is lost with traditional combustion. HCCI creates the same level of power as a traditional engine system, but it uses less fuel to create that power.
If you are a diesel fan, this probably sounds really familiar to you. Similar technology has long been used in diesel engines, but this is one of first times it has been brought to the gasoline engine. Now that we have the tools to make this technology real, we’re moving forward as quickly as we can.
Beyond the efficiency gains, there are other advantages to HCCI, too. It doesn’t require special exhaust systems, it’s adaptable to conventional gasoline engines and it can be used with E85 fuel. In short, we don’t need to design a brand new engine platform to effectively use HCCI. It can enhance much of what we already have.
We believe HCCI will become an important fuel-saving technology in our drive to reduce our nation’s dependence on oil. We’re continuing to perfect the interaction of HCCI with other elements like direct injection, variable valve timing and Active Fuel Management to maximize the potential benefits, which means we haven’t put HCCI into production yet. But we’re working hard to reach that goal to make it part of our future portfolio.
I’m interested in what you think about HCCI. I know it’s far from the only solution to our dependence on oil — and it certainly isn’t the only solution GM is working on — but it’s the one I’ve been working on lately. That makes it pretty important to me.
22 Comments
Tim
Maybe it’s time to think outside the box. There are many alternatives. http://peswiki.com/index.php/Directory:Engines
When considering E-Flex, the field opens even more because of the narrow power band and space/weight to power ratio considerations. HCCI may be harder to pull-off than just looking in another direction.
noel park
The great race car engineer Steve Smith once said that the way you get the weight of a race car down is to patiently find 1 or 2 ounces at a to remove until you meet your goal. Anyone who will not bother with these small gains will never be truly competetive.
Can we have this on the gas engine in the Volt? 15% better in the Volt would just increase the bragging rights.
I have repeatedly (with many others) called for better (Yaris like) mileage from the Aveo. 15% would get us a lot closer.
Good work! However, as good as advanced concepts are, actual hardware in the showrooms is 1000 times better. Bring it on.
kurtW
This sounds like a very worthwhile technology, along with direct injection and other engine improvements.
Hopefully (for most of us) HCCI will offer better vehicle performance (in economy, power, durability, etc).
As for enthusiast’s market, could HCCI be biased to offer more of the Horsepower they crave in a smaller, lighter package?
OhmExcited
My understanding is that one disadvantage of the HCCI engine is limited power range. On the other hand, that would make it ideal for electrically driven vehicles like the Volt. Is that your intention? Or to put them in all types of vehicles?
Edward Hayes
Let me indulge the numbers.
The U.S. uses 140 billion gallons of fuel a year. If we get 15% fuel savings from this one technology alone and it is implemented in all vehicles that would save 20 billion gallons a year. That is about three times the amount of ethanol the U.S. is expected to produce next year.
That is a significant step in the right direction and proves nothing is too small or insignificant, it all can contribute and make an important impact to our goal of energy independence.
ghent
how does it compare with Diesotto? i would say a 4-cylinder engine with V6 performance driving an S-Class sedan is simply fantastic!!! I hope GM put this into the new CTS soon.
HarryC
With all due respect to GM powertrain, would it be all that difficult to just bite the bullet (as Honda has done) and develop a world-class diesel engine?
Diesels can run on a wider range of fuels, include biodiesel and vegetable oil.
Paul
So are you going to be putting this in cars I’m interested in or just road behemoths? GM’s small care offerings are pretty lame in terms of MPG. I’d buy an Astra in a heartbeat if it got over 40mpg, which is possible because you’ve got several models in Europe that can do it.
When is GM going to stop being the Big Car company and start making great small cars for people like me?
Paul Eccles
The key words I read are 15% better mpg when combined with other advanced fuel saving technologies. What are these technologies?
How about using current technologies like direct gas injection and 6 speed automatics across the GM lineup to increase fuel economy now?
Dan
While HCCI is a very promising and exciting technology that will offer significant advantages, don’t lose sight also of the single most effective conservation and performance technology: weight savings.
All manufacturers, GM included, have met safety standards and customer expectations over the last fifteen years or so by adding significant extra weight to the typical vehicle. Heavier vehicles require larger engines, brakes, drivetrain components, everything is less efficient and detracts from fun to drive.
Many vehicles are 300 - 500 kg or 600 - 1100 pounds overweight! Intensive, long-term efforts to lower vehicle weight, component by component, will have many, many benefits.
Safety considerations will require more weight than equivalent vehicles from the 1980’s, but there are tremendous opportunities for improvement.
JohnP
I think it is great that GM is not sitting still or putting all of their mpg eggs in one basket. As prototyped I have read that there is a distinct change from HCCI to regular operation that I know will not be acceptable to an American driver. Technology is wonderful but to soccer moms and football dads it must be invisible. That’s why we never favored cars that shut themselves off at stoplights and restart when we push go, although in a golf cart it is more than acceptable.
Even as you develop this technology I am sure you are still looking at alternatives, such as Bruce Crower’s 6-stroke.
Edward Hobart
HCCI sounds great. If only I can get it on my hybrid Tahoe.
Luke
This is great! I love the torque delivered by the diesel engine in my Jetta. Having the extra efficiency and torque (albeit in a limited but useful power-band) for the gasoline-owning public would make the world a better place.
However, one of the advantages of a traditional Diesel engine is the flexible-fuel capability. I’ve tried to brew beer at home, and the expense of the ingredients and my lack of success makes producing ethanol sounds hard. I’ve also accidentally squeezed oil from various foods at home - this makes biodiesel sound easy. (I know that the economies of scale are vastly different between my kitchen and an industrial operation, but physics and chemistry don’t chage.)
Anyway, is there a chance that this thing could run off of veggie oil? What can you share about any alternative fuel capabilities that this engine may have?
Also, do you all intend this engine for conventional cars, or constant-RPM applications like the Volt?
Glen
Is this not like Smokey’s hot vapour engine? Is the intake charge pressure high enough to prevent precipitation of fuel during compression?
Charlie
Ms. Garavaglia said, “I’m interested in what you think about HCCI.”
Well, I don’t think much about it. Your article didn’t really tell us all that much about the technology of the engine and I can’t try one at the Chevy dealer today. How is it different from a diesel? How is it similar? What’s the extra gizmo on the head in the illustration for? What’s different about the combustion process? One wonders if an “External Communications Manager” actually understands what’s different about the engine.
I do think about 15% better fuel economy, of course, which is one of the reasons I don’t presently have a GM car. Will the HCCI engine change that? That depends on when I can buy it and what improvements other manufacturers make in the interim.
Alex
It is difficult to comment on this technology without understanding how it works and how it is different from other combustion engines. This is not explained in the top post. In general, anything that saves energy is good. My understanding is that the efficiency of combustion engines is only in 20% range. That is, only 20% of the energy in the fuel is converted to mechanical energy. Therefore, a 15% improvement (with HCCI) over the current engine technologies raises this to 23% from 20%. So, we still have a long way to go to reach a breakthrough engine technology.
E.L.
HCCI four cylinders should be next–and yes, this needs to be in the Lithium Two-Modes as well as the Volt.
Can’t wait.
E.L.
Oh yeah,
Weight is a big issue also in terms of handling etc.
And Paul, GM is a big car company. I don’t know what to make of hang-ups like that. It will always be big.
John Varga
Guess I should start out with saying that any technology that saves fuel is a good thing. But from what I know about this technology it is only a small thing. This is bascally controlled detonation and as such with a fuel such as gasoline can only be used under a small spectrum of the driving range. Thus it can probably be switched on only in a light load condition such as highway cruising. Increasing highway mpg (and emissions) but not much else.
I would agree with many of the previous posts that GM has a long way to go from an efficiency standpoint with the public. Truth being that GM has made good efficiency bigger cars and truck for years. Problem is that the public notices things like the Toyota Prius (boooo!) So to change the perception (perception is reality to most people, not facts) you need to PRODUCE a small percentage of really high mileage cars and maybe even small commerial trucks. Some of these vehicles are running around Europe as little diesels. (I’ve heard the emissions law differances and I don’t buy it.)
Also, as a parting note I would say that with a little company savy you could really take advantage of the grass roots bio diesel movement. It seems to be much more viable than the government supported ethanol project.
Keep up the new spirit on innovation.
John
Reiner Kappenberger
While I think HCCI is a step towards the right direction I don’t see it coming to a showroom anytime in the near future.
GM cars (and trucks) aren’t seen for efficiency, even so the latest Silverado is doing much better than the past. If I want a fuel efficient vehicle GM would be very low on the shopping list. Fuel efficiency is right now the key selling point for small cars.
As well the move from Full Size PickUp to Midsize is something that GM doesn’t really support. The Colorado/Canyon are sized to small to fit that shopping list (and they can’t even tow a descent trailer). As well even so they have smaller engines (and are lower weight) than the competitors they don’t get better mpg that one would assume from that.
Right now working on a Diesel Engine for smaller vehicles (cars and trucks) would be a much better short to mid-term investment for GM. As it looks right now GM leaves this area for the competitors (Honda, Volkswagen and most likely Dodge as they will source the engine from Daimler or Volkswagen).
Bottom line for me is that HCCI is a lot of hype right now with little real world impact for the next decade.
Reiner
Thunder
I agree with Charlie. It’s hard to tell you if we like something or not without more background information.
Will HCCI engines be able to rev like a regular gasoline engine, or are they limited like most diesels to a lower RPM range?
Are HCCI engines as noisy as the average diesel, or are they quiet like a gasoline engine?
It they’re quiet, rev and behave like a traditional gasoline engine plus get 15% better gas mileage, it sounds like a great idea. If it’s better than current engines that are being offered, how can it go wrong?
I think one of the most important things any car manufacturer can focus on now is weight reduction.
Mazda has reduced the weight of the Mazda 2 to about 2100 pounds I’d like to see GM do even better. Why not start developing hypercars now? Saving weight is the trend of the future and benefits efficiency no matter the engine or motor.
TC
What about an HCCI engine that drives a generator. The generator charges an ultra high capacity capacitor as well as LI batteries. The stored electricity powers hub-wheel motors on the vehicle. The UHC capacitor is used for that ‘burst’ of speed while the LI batteries provide power to sustain movement. Put this into a truck and you have a system that powers the motion of the truck as well as provides electrical power while the truck is stationary. Good for contractors, concessionnaires, and others who require the capability to transport large items and also require electricity when they arrive at their destination.
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