Confused by "flex fuel?" Perplexed by "plug ins?"
 
With the ever growing number of options among alternative fuel-powered vehicles and the rapid growth of technology, it's getting tough to understand how it all works and what's best for you as a consumer.
 
Michael Omotoso, J.D. Power's senior manager of global powertrains, was willing to help unravel the confusion.
 

Diesel
 

Question: How do diesel-powered cars work?
A: They basically work pretty much the same as a conventional car, but the main difference is that an engine powered by diesel fuel is 25 to 30 percent more efficient. That's because diesel fuel has a higher energy content than gasoline, which results in 25 to 30 percent higher fuel mileage.
 
Q: How much more expensive is a diesel-powered car to a comparable conventional one?
A: For instance, the Mercedes E Class diesel costs just a thousand dollars more than the nearest gasoline E Class.
 
Q: What are the disadvantages of diesel-powered cars?
A: Diesel exhaust is dirtier than gasoline. It has nitrous oxides and diesel particulate matter -- basically soot. But diesel fuel is much cleaner than it used to be because we have low sulfur diesel instead.
In addition, we now have exhaust treatment systems that get rid of most of the nitrous oxide and particulate matter.
 
Q: So what type of consumer would be most likely to benefit from a diesel-powered car or truck?
A: Diesel would be best for people who drive long distances. Right now, we see more diesels in the luxury segments. Mercedes has the E Class diesel model, and they will soon have three kinds of diesel powered trucks or SUVs. They are the ML Class, GL Class and R Class. There also is now a diesel-powered Jeep Grand Cherokee.
 
Hybrids
Q: Most of us know by now that hybrids are cars and trucks that have both electric batteries or generators as well as internal combustion systems. But what's new these days in the world of hybrids?
A: The latest thing are plug-in hybrids, but more about that later. What's also new is that General Motors has launched hybrid-powered versions of its Big Chevy Tahoe and GMC Yukon SUVs. Up until now, hybrids have mostly been small cars and crossover vehicles.
 
Q: I often hear from readers who own hybrids who are worried that it will cost them thousands to replace a battery in a hybrid if they need to do that. What's the story on these batteries' replacement and their costs?
A: Replacement costs are still a little unclear. These batteries are designed to last eight to 10 years. We might soon see some of those people who bought the first generation of the Prius needing to replace their batteries in a couple of years. We think that Toyota will simply take the batteries back and replace them, but we are not sure at what cost.
 
Q: What type of buyer is best for hybrids?
A: Hybrid buyers are typically very environmentally conscious, and they are better educated and wealthier than the average vehicle buyer.
But the hybrid market is heavily biased toward the East and West coasts, where the big cities are and because of congestion. There are also states that have California emission standards and you can't sell diesels in those states. So if people are looking for alternative fuel vehicles, they need to go with a hybrid.
 
Plug-in hybrids
Q: First, what's the difference between plug-in hybrids (also known as extended range vehicles) and other electric cars?
A: The main difference is that electric vehicles do not have an internal combustion engine while extended-range electric vehicles do. The range (distance you can drive at one time) on an electric vehicle as of now varies from 30 to 100 miles.
 
Q: So what's the biggest obstacles to widespread use of electric vehicles?
A: One main obstacle is the safety of the batteries and the other obstacle is the cost of electric vehicles. The Tesla sports car, for example, costs between $75,000 to $100,000. The average cost of a car today is about $29,000.
 
Q: So what type of owner or driver will likely be drawn to all-electric vehicles?
A: These will be people who are very environmentally conscious people who live in congested cities and who have short commutes of 40 miles or less. And technofiles who want to be the first ones to buy the latest thing also will be attracted to them.
 
Q: Now let's talk about plug-in hybrids, also known as extended-range electric vehicles.
A: These vehicles use a combination of conventional gasoline or internal combustion engine and a lithium-ion battery.
Lithium-ion batteries are lighter and they store more energy. The plug-in part is that you literally plug the vehicle into a household socket with a cable, and you charge up the battery overnight.
The next morning, you would get up and go to work and drive on electric power only for 40 miles. The reason that auto manufacturers aim for the 40 miles target is because studies show that 75 percent of Americans have a commute of 40 miles or less round trip.
 
Q: So about how far away are we from production of plug-in hybrids, such as Chevrolet's Volt?
A: We're about two to three years away. General Motors says the Chevy Volt plug-in hybrid should be ready in 2010 , though some people are skeptical about that.
 
Q: Why the skepticism?
A: There are still issues with the battery. Basically this is the same kind of battery used in laptop computers, cell pones and iPods, for instance. The batteries have heated up and in some cases, caught fire. That's what happened with a few Sony laptops. Obviously you wouldn't want that to happen in a car -- huge lawsuits would probably follow.
 
Hydrogen fuel cells
Q: Explain how hydrogen fuel cell vehicles work.
A: A Hydrogen tank is on board that generates electricity and there's also a battery included. What comes out of the exhaust system is just pure water. Hydrogen fuel cell powered vehicles are very clean. Honda just launched its FCX Clarity sedan, which uses hydrogen fuel cells, but it's only come to California so far, and you lease it, not buy it.
 
Q: What are the disadvantages to hydrogen fuel cell cars?
A: The big disadvantage is the high cost, and I think there are still issues with the range of these vehicles, similar to plug-in vehicles. The safety issues surrounding the use of hydrogen fuel cells have been mostly solved.
 
Q: What kind of person or driver will hydrogen fuel cell cars be best for?
A: It would be similar to the plug-in car driver, except the hydrogen fuel cell-powered car would have a little more range.
 
Q: So how long will it be before we see hydrogen fuel cell cars every day?
A: The technology is there but it's much more expensive than either plug-in hybrids or hybrids. It will be 10 years or more before we start seeing hydrogen vehicles in any significant numbers.
 
Flex fuel
Q: What are the main advantages of flex fuel vehicles that can use either conventional gasoline or ethanol?
A: The main advantage is the fact that we are reducing our consumption of oil by using ethanol. Most of the ethanol we have in the United States is from corn, and grown domestically, and that helps domestic farmers. A gallon of ethanol is also cheaper than a gallon of gas.
 
Q: So what are the disadvantages of using ethanol fuel?
A: You get worse fuel economy with ethanol fuel than you do with gasoline. The ethanol has a lower energy content, so you pay a penalty of 25 percent or so lower mileage. That's a pretty big drop, and a lot of people don't realize that will happen. So if you get 25 miles per gallon with gasoline, you'll only get 17 and a half miles per gallon with ethanol.
 
Q: What about the idea that relying on ethanol fuel will raise our costs of corn and thus drive up the cost of food?
A: There is some truth to that. Popcorn is more costly, tortillas are more expensive and even meat costs are higher because the farm animals are fed with corn. But with ethanol you are importing less gasoline, which has hit $110 a barrel. Using ethanol also would allow people to continue to drive larger cars and trucks. But if you want to reduce fuel consumption without ethanol, we're going to have to shift to smaller cars and trucks.
 
Q: So what else can we do to lessen our dependence on corn for making ethanol fuel?
A: One alternative to corn for ethanol is sugar cane, which is used in Brazil. The other method that the government would like us to use is cellulosic ethanol. This is ethanol made from garbage, waste material, switch grass or wood chips. It would be an advantage to use materials that you normally throw away.
 
Q: How's the infrastructure for ethanol right now?
A: There are only 1,400 ethanol fueling stations in the whole country, and they are mostly in the Midwest. That compares with 170,000 gas stations.
 
Don Hammonds can be reached at dhammonds@post-gazette.com or 412-263-1538.