Choosing an Alternative Car
Filed Under: green automotive technology, Green Technology on December 1, 2010
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by Aaron Turpen, AboutAlternativeCars
A recent survey conducted by Harris Interactive for Mercedes-Benz USA found that most Americans don’t have the basic knowledge of the fuel alternatives out there to make an informed decision about alternative vehicle options. This means that many may be holding off on buying one because, well, they don’t know what they’re getting into.
Since that’s kind of the point of About Alternative Cars, I guess I should get crackin’ on explaining the differences and which are better for what driving need or lifestyle.
For this, we’ll approach it as if you have total access to every major fuel alternative available today and are merely making a choice based on need. It’s obvious that gasoline and diesel engine options are going to be straight forward for most: the standard EPA numbers will tell you what you probably want to know.
So our focus will be on the other fuels for alternative cars out there: all electric, biodiesel, diesel electric hybrid, ethanol (flex-fuel), gasoline electric hybrid, and methane gas (CNG/LPG).
First, a point of clarification: a hybrid is any vehicle that operates on more than one fuel and propulsion type. So a gasoline electric hybrid runs on both gasoline and electricity, either at the same time or alternately. In these hybrids, there are also plug-in hybrids and range extended hybrids. Plug-ins are capable of running for very short distances on just electricity whereas range-extended hybrids are always running on electricity and use the combustion engine as a generator to provide power.
Now, let’s look at the options.
All Electric
There are a handful of mass-produced all electric cars, nearly all battery electrics, that are available today or will be available by the end of the year. There are two basic categories of electric car: neighborhood (or low speed) and standard (highway-ready).
Neighborhood electric vehicles (NEV) are usually capable of no more than 35mph (often less) and usually average about 40 miles range per charge. These are not allowed on highways or freeways and are meant for around-town driving or commuting. Until recently, nearly every electric car widely available was an NEV.
Standard electric vehicles (EV) are similar to NEVs, but are capable of highway speeds and are licensed and operated much like a normal combustion engine vehicle. Most on the market today are capable of about 100 miles per charge and speeds of at least 75mph.
Most drivers don’t require more than 40 miles per day from their car, believe it or not. Many people’s average driving day covers only about 24-27 miles. So for the average driver, electric is definitely an option. It will get you through your normal day, but will not get you the 200 miles to grandma’s house on the weekend.
The majority of people need a lot less range than they think, however, but battery electrics have another down side: price. The car usually has a premium price or will require a lease payment for the batteries. They also have a limited life span, as most manufacturers are not offering more than 7 years warranty on the batteries. Lithium-ion batteries (the most commonly used in longer-range vehicles) have a lifespan measured in about 7-10 years. Lead-acid batteries have less than half that.
Still, for the majority of car owners, that’s probably not much of an issue. If you currently spend $40/month on gasoline for your car and your battery lease on an electric car is that much, you’re not losing any money. Currently, many of the price premiums on electrics are negated by state and federal tax incentives as well.
Biodiesel
There are several types of biodiesel on the market and people talk about all of them, often inclusively. They are very different, however, so we’ll address the big ones individually under this title.
Biodiesel itself is not usually 100% biologically-derived, but is instead a mix of bio-based diesel fuel and standard petroleum diesel. At the pump, these will be listed with a “B” number: B15, B10, B85, etc. The number after the B indicates the amount of biologically-based diesel in the mix, so B85 is 85% bio and 15% petroleum. Most diesel fuel vehicles, such as heavy-duty trucks and European cars, can operate on the lower mixes of biodiesel like B15. Running on higher mixes may require alterations to the engine block or components, especially with TDI and similar technologies.
Vegetable Oil is often used to run a diesel vehicle that’s been converted to do so. Most biodiesel is, in fact, vegetable oil-based and diesel engines were originally made to run on veggie oil, but today’s engine technology usually requires some changes be made to the block and components to do so. The seals, injectors, and other parts may have trouble utilizing pure vegetable oil and fuel gelling is always a concern.
Kitchen Grease is another popular biodiesel type. Often called “greasel,” this is used kitchen grease that’s been filtered of contaminants and is burned as vegetable oil in an engine. Like vegetable oil, greasel requires modification to the engine to be used.
There are both vehicles and conversion kits on the market that are made specifically to run on pure biodiesel and/or vegetable oil. These kits or vehicles will have fuel heaters built in or will require additives in the colder months to keep the fuel from gelling.
Diesel Electric Hybrid
These types of vehicle are gaining ground in Europe and the first of them will be available in the U.S. soon. They are hybrids that operate as a normal combustion engine car (in this case with a diesel engine) coupled with an electric drive train. They can be either plug-in electric or straight hybrids.
Diesel has the advantage of being a fuel that’s easier to make and that often results in much higher mileage per gallon than gasoline. Newer diesel engines are also much less polluting and are often on par or even better at lowering pollution levels than are gasoline engines.
In range-extended hybrid applications, in which the electric drive train is all that powers the car while the diesel engine acts as a generator to provide electricity, the diesel electric hybrid can really shine. Diesel engines have a small, optimum rotations per minute (RPM) range and under these conditions, that can be utilized for maximum efficiency.
Ethanol
Ethanol is a very controversial fuel in the United States because of its primary source, which is corn. Corn is not the only option for ethanol production, however. In Brazil, which has the largest number of ethanol cars per capita in the world, most ethanol is made from sugar cane. Other sources can include flax, algae, and others.
Most vehicles in the U.S., like with biodiesel, are not capable of running on pure ethanol. Many are standard gasoline engines and can only run 10-15% ethanol mixes with regular gasoline. Ethanol, like biodiesel, is labeled at the pump with its bio-content mix as E10 or E15.
Some car makers, of course, are making engines that are specifically built for ethanol use and allow up to E100. There are few of these on the road and the pure ethanol is harder to come by, but these vehicles are also capable of running on standard gasoline as well. They are commonly labeled “flex fuel” vehicles.
Gasoline Electric Hybrid
Similar to a diesel electric hybrid, gasoline electric hybrids are much more common in North America. These include all brands of hybrid, whether they be straight hybrids, plug-ins, or range extended hybrids.
These cars usually have much better fuel mileage than their gas-only counterparts. Their MPG (miles per gallon) is often higher by 20% or more. They often have a price premium, however.
Methane
Methane is the proper name for natural gas and is available for vehicular use as compressed natural gas (CNG), liquefied natural gas (LNG), and propane. CNG is the most common of these.
These vehicles run using the methane gas as a fuel, burning it in the same way your gasoline car burns gasoline fumes. In fact, the two engine types are very similar and conversion kits to go from one to the other are relatively common.
Natural gas has a much lower emissions profile than does gasoline or diesel, because methane has a high ratio of hydrogen to carbon (1:4). Burnt methane has almost no particulate matter (PM) and little of other emissions and is thus often said to be “clean burning.”
Several manufacturers offer methane vehicles, but fuel availability to the public remains a problem. Propane is readily available, but requires a relatively large storage space per mile driven whereas compressed methane, such as CNG or LNG, does not.
Choosing Based on Need
Now that you know the options available, let’s consider your needs. Most drivers have three basic requirements for a vehicle: range, fuel availability, and specialty tasks.
Range is obvious, as some drivers have a 24 mile commute while others have a 90 mile drive daily. Fuel availability is something that requires some work on the driver’s part if fuel alternatives are being considered. Specialty tasks include things like a need for 4-wheel drive, the ability to carry heavy loads, or a multi-passenger capability.
Range - Of the alternative vehicle types we’ve gone over here, only all electric vehicles have a range issue. For most who consider this a problem, but have a short daily drive, options like rentals and car sharing are definite solutions. If you’re driving 27 miles daily and visit grandma or Uncle Bob every couple of months or just during the Holidays, you probably don’t really need to worry much about range.
Fuel Availability - This is the biggest issue with alternative cars. In most areas, gasoline and diesel fuel are readily available. In many, propane is also easy to get. CNG and LNG are not so easy to find and ethanol is really only easily accessible in the Midwest.
Look around, however, and you might be surprised at what’s available. Biodiesel is becoming more and more common, especially at truck stops and travel centers. Those places often also have methane options beyond propane as well. Many places sell CNG to the public, but are not what you would consider your normal “gas station.” Sources for these fuels are available online. Including this one from the U.S. Department of Energy.
Specialty Requirements - These are often a function of the vehicle, not the fuel. There are a few things that you will not likely see as a combination, though. A combination heavy vehicle and ethanol or gasoline hybrid is not likely. Many medium- and heavy-duty vehicles, however, are commonly biodiesel, diesel electric hybrid, and methane vehicles.
Most specialty requirements are not exclusive of most fuel types. So it’s not likely that this need will remove a fuel alternative from your list.
Conclusion
It’s hoped that this breakdown of the various alternative fuels and drive types will help you make a better decision when choosing a new vehicle. There are many great options for replacing standard gasoline or diesel in our daily lives, all available right now.
In the next ten to fifteen years, more alternatives such as hydrogen fuel cells and algae-based fuels will also be coming to the open market.
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