Here's what I learned and things that I wanted you to know when deciding among low-mileage gasoline cars, diesel-powered vehicles and gasoline-electric hybrids...
Fuel Economy Reality
Let's start with the fuel economy numbers on a window sticker of a new vehicle--studies show the average drive can expect only 75 percent or so of the mileage figures that are on the sticker of their new vehicle.
This has changed some since the federal government began phasing in a new way to calculate those fuel economy figures for the window stickers. The goal is to make the fuel economy statistics better reflect what real-world drivers will get.
What I discovered was that the numbers don’t come from real-world driving but from U.S. Environmental Protection Agency emission testing procedures on new vehicles. This means that the laboratory procedure does not involve cars using gasoline for the testing. And let’s don’t forget that there are a lot of other factors that we need to take into consideration like the weather, terrain, driving habits and condition of the vehicle—these factors affect the kind of mileage that regular drivers get.
This is not to say the reported numbers can't be used for comparison purposes between vehicles, especially those in the same class.
But you should know that a few owners of gas-electric hybrids, have complained that this is a huge difference between their mileage and that posted on their vehicle window stickers. Honda, Toyota, Lexus and Ford hybrid vehicles have real-world mileage via graphical displays on the dashboard, making it easier for the driver to pay attention to fuel use and mileage statistics more so than in conventional vehicles.
Consumer Reports magazine, which calculates its own fuel economy stats, noted that its Toyota Prius hybrid test car got 44 miles a gallon in real world driving, not the city/highway rating of 55 mpg that the government reports.
Do hybrid vehicles give you better mileage than like-sized vehicles in their class? Yes, but just be aware it will take more than just a gasoline-electric powertrain to get the fuel economy they think they've been promised.
Hybrid Pricing
Gasoline-electric hybrid vehicles cost more than non-hybrid vehicles—anywhere from a couple thousand dollars to several thousand dollars.
For example, the Honda Civic Hybrid has a starting manufacturer's suggested retail price of more than $22,500 for a base, 2007 model. A 2007 Civic LX gasoline-powered sedan with many comparable amenities carries a starting MSRP that is some $4,800 less.
True, the 2007 Civic Hybrid is rated by the EPA at 49 mpg in city driving and 51 mpg on the highway, for a combined 50 mpg. This is 30 percent better than the combined rating of 33 mpg for the gasoline-powered, 2007 LX model.
But even if you could maximize your fuel savings and gets the full 17-mpg benefit in the Hybrid, you would need more than a dozen years of 15,000-mile annual travel before the gasoline savings—calculated with gasoline at approximately $2.40 a gallon—would recoup the $4,800 extra paid for the Hybrid over the traditional Civic LX.
Other Hybrid Issues
Like any new product in this world, the auto industry has predicted that the hybrid vehicle prices will drop as they become more plentiful and there are greater economies of scale.
Today's hybrids are fairly new which means that the technology mates an electric motor to a gasoline engine so the electric motor supplements the engine at times. This reduces greenhouse gases as well as optimizes the use of gasoline.
Hybrids have electronic engine controls that modulate the smooth working of these two systems together and manage power delivery to maximize fuel efficiency.
Hybrids store electric energy on board in large battery packs. The packs are warranted for eight to ten years, depending on the manufacturer, current prices are about $3,000.
Diesel Efficiency
Diesel-powered passenger vehicles are another fuel-efficient choice.
Popular in Europe, diesel models are limited in their availability in the U.S. because five states—California, New York, Massachusetts, Maine and Vermont—prohibit their sale due to emission restrictions. And it’s worth mentioning that gas-electric hybrid vehicles are sold in all states. Indeed, hybrids are far cleaner in many emission properties than even conventional gasoline vehicles.
Having said that, diesels are known for getting extra mileage out of every gallon of fuel, they offer better torque than many gasoline engines. And their price differential over gasoline models generally is much smaller than that for hybrids.
For example, Mercedes-Benz's midsize 2007 E320 diesel sedan has a starting MSRP of $51,550, which is only $1,000 more than the starting price for a 2007 E350 gasoline sedan.
Yet the 3.0-liter V6 in the E320 BLUETEC sedan, as the diesel version is called, puts out an amazing 388 lb-ft of torque starting as low as 1600 rpm and compares with the 258 lb-ft of torque starting at 2400 rpm in the 3.5-liter V6 gasoline engine in the E350 sedan.
The diesel E-Class's fuel economy rating is 26/35 mpg, for a combined 30 mpg, and compares with 19/26, for a combined 21 mpg, in the gasoline E350.
So, if you maximized the diesel's fuel economy and were able to get 9 extra miles per gallon, it would take less than three years to recoup the approximately $1,000 extra cost for the diesel engine in the E-Class if diesel prices were in the neighborhood of $2.40 a gallon.
Diesel engines are getting cleaner all the time. Thanks to cleaner diesel fuel with lower sulfur content now available in the U.S. and new vehicle tools that filters or traps troubling engine particulate emissions, diesels are becoming cleaner and cleaner all the time.
Mercedes states that its Bluetec is the "cleanest diesel in the world." And with all of the advancement with diesel engines, people still complain that diesel cars typically—though not always—are noisier than gasoline-powered vehicles. Some don’t like the telltale odor that is associated with diesel vehicles as well.
And, you can’t always find a gas station that has a diesel pump. In some cases, drivers may need to drive farther from suburban neighborhoods to find a place to fill up.
But needless to say, diesel engines have been with us for a long time—the first diesel-powered passenger car was a 1936 Mercedes—and diesel engines are known for their durability. That is why they're standard engines under the hoods of big semi-trucks.
Gasoline Models Can Shine
You don’t have to go to far from conventional gasoline models to find fuel-thrifty vehicles. But you will need to focus on small, lightweight vehicles in order to maximize the gas they use.
Gasoline models with the best fuel economy all have four-cylinder engines, rather than V6s or V8s.
