Gas engines: Here to stay

[leobold1]

Internal combustion here to stay - May. 2, 2008

Despite its limitations, the internal combustion engine won't be pushed aside so easily, but it can be made better.

By Peter Valdes-Dapena, CNNMoney.com staff writer
Last Updated: May 3, 2008: 7:12 PM EDT

NEW YORK (CNNMoney.com) -- Despite all the hype for electric cars and hydrogen fuel cells, experts say we'd better get used to pumping gas, but we can look forward to much better fuel economy down the road.

"For the foreseeable future, the gasoline engine will stay the predominant power source," said Uwe Grebe, General Motors' executive director for advanced powertrain engineering.

That's because, despite it's imperfections, the internal combustion engine has a lot of inherent advantages but plenty of room for improvement. As those improvements are made, future gasoline engines will be more and more fuel efficient, making it tougher for competing technologies to show a big benefit.

Another reason is the fuel itself. Whether we're talking about diesel fuel or gasoline, it's hard to beat hydrocarbons for delivering energy in a potent, easy-to-handle package.

Small non-hybrid gasoline engine cars already get more than 35 miles per gallon on the highway. But only about 15 percent of the energy in gasoline actually makes its way to the wheels, said Fedewa.

That leaves plenty of upside potential, he said.

Gas/electric hybrid technology is a major step in boosting efficiency, but it's complex and expensive. Smaller changes are also squeezing out more of internal combustion's wasted power at lower cost.

Engineers are working on some of the subtler aspects of the engine's inner workings: The timing and spacing of the opening of valves, when and how fuel is injected into the cylinders and when the spark goes off are just some of the things that can be tweaked to extract more motive power from gasoline.

Combining all of these technologies, several car companies are working on something called "homogenous charged compression ignition" - HCCI for short - that allows gasoline engines to mimic the behavior of diesel engines.

In an HCCI engine, gasoline is ignited inside the cylinder using compression and the engine's own heat without the need of a spark. (Spark plugs are still used when the engine is cold.) While there are differences in how the engines work, this is essentially the same way that a diesel engine ignites diesel fuel.

Diesel-powered cars go up to 35% farther on a gallon of fuel than similar gasoline-powered cars. The downside of diesels is that they create more pollution, and the exhaust-cleaning technology needed to deal with that pollution is expensive.

That's why HCCI engines seem like an attractive option, provided engineers can get all the bugs worked out. HCCI engines still won't go as far on a gallon as diesel engines, in part because diesel fuel puts out more energy, but they should get about 15 percent better fuel economy than current gasoline engines, said Grebe.

Electrifying technology

Another process that's already well underway is the "electrification" of more systems within the car. In most cars now on the road, power steering and brakes get a boost from hydraulic pumps or vacuums powered directly by the car's engine. Air-conditioning compressors are also powered directly by the engine.

Many new cars now use electrically-assisted power steering and power brakes as well as electrically operated air conditioning compressors. These sorts of systems are an absolute necessity in gas/electric hybrid cars. Without them, the power steering and brakes as well as the air conditioning would stop working whenever the engine stopped.

Electrification of these accessories could add up to 10% to a vehicle's fuel economy said Nick Cappa, an advanced technology spokesman for Chrysler.

The final big step in the electrification of the car will be to remove the gasoline engine from the job of moving the car's wheels. That's the benefit of a so-called range-extended electric vehicle like GM (GM, Fortune 500)'s planed Chevrolet Volt.

While the Volt will get enough power to drive 40 miles or so just by plugging into a socket for a few hours, for longer trips extra power would come from a small gasoline engine. The engine would produce electricity that would be stored in a battery to drive the car.

Freeing the engine from directly driving the car has another big benefit. With the engine no longer connected to the wheels, it becomes easier to install entirely different powerplants in what is otherwise the same vehicle.

Hydrogen alternative

That could make vehicles like these the next step to hydrogen fuel cell cars. Both Ford (F, Fortune 500) and GM have created range-extended plug-in vehicles with hydrogen fuel cells to generate additional power instead of internal combustion engines.

Hydrogen fuel cells combine hydrogen with oxygen to create water while giving off energy.

The hydrogen fuel cell itself is nearing commercial viability, said GM's Grebe. The problem now is that there isn't much "hydrogen infrastructure" yet. In other words, if you were given a hydrogen fuel cell car today, finding a place to fuel it would be tough.

But talk of pumping hydrogen gas into electric cars brings to mind one of gasoline's big advantages.

The reason range-extended electric vehicles need their ranges extended in the first place has to do with "energy density." That's the amount of energy stored in a given amount of space within the vehicle, including both the fuel and whatever it's kept in.

The low energy density of batteries is what limits the range of electric vehicles. A battery big enough to take a long trip could be as big as the car itself. Compressed hydrogen, including the thick-walled tank needed to store it, is better than a battery.

But it's still not nearly as good as a simple plastic bladder filled with gasoline. If you want to go somewhere far away, there's still nothing better than gas.

At least not for now.

[BrianK]

I wonder if any studies have been conducted to determine vehicle use. When I see advertisements for 35 MPG highway. I kind of chuckle at the deception of advertising.

Deception because I see people stuck in traffic using interstates as a short cut to go to work. My guess is most people use their vehicles to commute to work & back and for local shopping. That isn't highway by any stretch of the imagination.

I don't know how the electric/small gasoline engine concept works but it does seems reasonable given what I think is more likely to be typical use. I could envision a small 5 HP Briggs & Stratton type of go cart engine kicking on to turn an alternator to recharge batteries as they discharged during use.

Would that reduce consumption enough to cause airline & better mass transit to cost less to use for long trips? I don't know but with more people retiring and less real desire to be going someplace that could harbor anti American sentiment, changing how vehicles are used does seem like it's on the minds of manufacturers.

[cato2]

Originally Posted by BrianK

I wonder if any studies have been conducted to determine vehicle use. When I see advertisements for 35 MPG highway. I kind of chuckle at the deception of advertising.

Deception because I see people stuck in traffic using interstates as a short cut to go to work. My guess is most people use their vehicles to commute to work & back and for local shopping. That isn't highway by any stretch of the imagination.

I don't know how the electric/small gasoline engine concept works but it does seems reasonable given what I think is more likely to be typical use. I could envision a small 5 HP Briggs & Stratton type of go cart engine kicking on to turn an alternator to recharge batteries as they discharged during use.

Would that reduce consumption enough to cause airline & better mass transit to cost less to use for long trips? I don't know but with more people retiring and less real desire to be going someplace that could harbor anti American sentiment, changing how vehicles are used does seem like it's on the minds of manufacturers.

You bring up some good points Brian.

I have lived in the Los Angles area at one time. And the grid lock of that city is infamous. Unlike most major cities of the east coast, the population vs. job location is spread out. Downtown Los Angles is not were most of the inhabitants work. People commuting from Venture or Orange county to work in the Los Angles area is common. As well as the those who traverse from Venture, cutting through Los Angles to work in Orange country.

And that is not the only city were a high mileage commute is common. Oklahoma City, Jacksonville Fl. and El Paso are cities that share the problem of extreme travel.

While hydrocarbon combustion will be the major component of the matrix, I see alternative combinations arising in our future. In an urban setting these will seem to be a good alternative. But when travel is involved, the infrastructure is not yet built that would allow long distance traveling. There are just not enough stations built as of yet to service alternative fuels for these motors. Los Angeles has Natural gas stations right now available, but I am not aware of any other cities.

The gasoline engine may be here to stay for the foreseeable future. But the cost of operation will increase as well.

One other note. Many cities are now going to Natural Gas, including my city. Los Angles is one of those cities as well. It seems that the State of California, which has sought solutions since the 60's, may hold the answers to these problems since they have been the first state to invest heavily in solutions.

[BrianK]

At one time I was involved with electric vehicles. The company I worked for was on board with trying to promote them as a viable replacement. The facility I ran was named by FERC as the repair center for the east coast for electric vehicles. Those were fun times for the mechanics because there is nothing more challenging that learning something new.

We even had one of GM's EV1 cars to experiment with. My sons have coffee cups made from the same synthetic material the body of those cars was made from. That and the original spec sheets that came with the car.

Other things of interest for me was shooting a promotion vido on my property for a Canadian made battery powered Van. That was not a good design because the battey pack took up a lot of the possible carrying capacity of the Van. I believe it had something like 27 deep cycle marine type batteries as the power source. The range was limited and cold weather reduced the range even more.

But without those as a beginning the ongoing progression wouldn't be possible.