Why Gasoline Is Still King
From the Magazine: Wednesday, December 17, 2008
Any sufficiently advanced technology is indistinguishable from magic.
--Arthur C. Clarke’s “Third Law”
A little respect, please. For gasoline. Yes, we know it contributes to pollution, and yes, it is “nonrenewable,” and yes, we still haven’t learned to use it as efficiently as we could. But the fact remains: no other fuel delivers so much energy in such a small package with such flexibility, utility, safety, and simplicity. That’s precisely why it caused so much national heartburn when its price spiked this summer. It was like suddenly being told you had to pay for air.
Even though the higher prices caused a temporary downturn in gasoline consumption, the general figures still hold true: We Americans drive our 210 million motor vehicles—from abstemious little Smart Cars to big Mercedes S-Class sedans and hulking Hummers—7 billion miles and consume 390 million gallons of gasoline every day. But we still don’t seem to appreciate this amazing liquid. Gasoline is just … well, there. At the pump in about 167,000 locations across the country. Ready to power a Lamborghini or a leaf blower. One gallon contains so much energy (113,000 to 117,000 Btus) that even though almost 80 percent of it is wasted as heat and exhaust, it will still carry a loaded Chevy Suburban over the mountain or a Mini Cooper to the mall swiftly and with ease.
U.S. refineries currently wring about 20 gallons from each 42-gallon barrel of oil they process. And although this mysterious mixture of hydrocarbons has been adulterated, oxygenated, and reformulated to improve its performance and reliability and comply with ever-more-stringent air pollution standards, gasoline remains an incredibly elegant helpmeet for our personal transportation.
Once feared for its explosive properties, sometimes used as a cleaning fluid, and often dumped by early refiners as a “useless” byproduct, gasoline grew to become the magic elixir of the modern world. We’ve lost sight of the magic because gasoline is so commonplace. We grumble about its price, but we don’t really think about its true value to us.
We’ve lost sight of the magic because gasoline is so commonplace. We grumble about its price, but we don’t really think about its true value.
Whatever the price, gasoline is still an extraordinary bargain. The utter simplicity of its daily use belies its exceptional complexity. Crude oil can contain as many as 100,000 carbon compounds, and gasoline is a refined blend of several hundred of these compounds, formulated to perform in extremes of hot and cold and at widely varied altitudes, not burn too fast or too slowly, burn as cleanly as possible, and remain stable during transportation and storage.
Gasoline comes to us through a prodigious formulation and delivery infrastructure. It leaves refineries mostly through pipelines and is stored in bulk terminals near main consuming areas. Then, it is pumped from the terminals into tanker trucks that typically hold 10,000 gallons. Special additives such as ethanol or detergents that keep fuel systems clean, as well as lubricants and stabilizers, are blended into the gasoline as it goes into the tankers. When you buy a nationally branded gasoline, you are essentially getting its special additive package. The gasoline itself may have been piped to bulk storage from refineries that have processed a variety of domestic and imported crude oil, which makes it impossible to boycott oil from a particular country by your choice of gas station.
The result of all this complexity, this technical sophistication in manufacture and delivery, is gasoline of reliably high quality throughout the country—a user-friendly substance, simple to dispense; a compact and powerful liquid sitting in our fuel tanks, waiting to be summoned into the combustion chambers of the engines of our cars, boats, motorcycles, lawn mowers, string trimmers, and home generators. We may expatiate on the latest developments in electric cars and the delicious prospects of hydrogen fuel cells and various biofuels made with everything from switch grass to garbage; we may earnestly speculate about flywheels and compressed air and various gases, natural and unnatural—but we go with gasoline.
A gallon of gas weighs about 6.3 pounds and produces roughly 35 kilowatt hours of energy. That’s enough to burn a 100-watt light bulb continuously for more than two weeks. A lead-acid battery could do the same thing without needing a recharge—if it were the size of a desk and weighed a ton. Energy density is the point. We just haven’t come up with a fuel or a device that will safely and economically offer the same calorific value in such a small space as an automobile’s gasoline tank. Compressed natural gas (CNG) and liquefied natural gas (LNG) intrigue us, but the problems of storing them (or hydrogen) in a car in sufficient quantity to approach gasoline’s range and performance continues to be a sticking point. We always come back to density.
Oddly, nothing better illustrates the overall efficacy of gasoline than an electric car. In 1900, when electric, gasoline, and steam cars were vying with one another, an article in American Monthly Review of Reviews pointed out that the gas car had “developed more all-round good qualities than any other carriage,” not the least of which was that “it carries gasoline enough for a 70-mile journey and nearly any country store can replenish the supply.” It was true back then and it remains true today. The standard to which electric cars aspire—for speed, flexibility of operation, and range—is the gasoline standard.
We may earnestly speculate about flywheels and compressed air and various gases, natural and unnatural—but we go with gasoline.
Right now the impressive Tesla electric roadster is the darling of the automotive press. Its beguiling style and cutting-edge technology have made it a sensation, albeit an expensive one, at close to $100,000 a copy. Instead of conventional lead-acid batteries, or nickel metal-hydride (NiMh) batteries such as those that are used in the Toyota Prius hybrid, the Tesla draws its energy from an elaborate and sophisticated array of 6,831 interconnected lithium-ion batteries—the kind used to power top-line laptops. These batteries, each a little bigger than a common AA alkaline, are immersed in a liquid cooling system to prevent them from becoming too hot and possibly bursting into flames when under the stress of feeding a total of 375 volts to the Tesla’s electric induction motor.
Enthusiasts see the Tesla as the “I told you so” electric car, with its world-class acceleration (a reputed 0 to 60 mph in 4 seconds), a top speed of over 120 mph, and a claimed range of 220 miles. But that range will bear some scrutiny in real-life conditions as Teslas start getting into the hands of owners. Automotive testers are already sounding some warning bells. John O’Dell, who test-drove the car for Edmunds Inside Line, notes that its range may be “more like 180 miles if you like to goose it every once in a while and down around 150 if you regard speed limits as mere suggestions.” In other words, if you drive it like a sports car (which it is) you will experience a steady deterioration of performance as you drive. Add the weight of a passenger or the challenge of a curving road through hills and the downturn is more pronounced. O’Dell observes: “The quickest your electric sports car will be is in the first few minutes after you leave the garage. It just gets slower after that until you return home again.”
Make no mistake—the Tesla is an impressive performer, praised for its handling, its responsiveness in tight spots, and its rocket-like acceleration. It is often compared to a Porsche 911. Okay. Let the Porsche drag with the Tesla a few times. The Tesla may well reach 60 mph slightly faster than some versions of the 911. But, while the Tesla’s batteries are electronically panting and cooling off and its dash displays are flashing warnings about decreased range and automatically restricting the electric motor’s torque, the Porsche will go merrily on its way and cruise up to 400 miles on the remaining gasoline in its 17.7 gallon tank.
And while the Tesla is recharging its batteries over a period of hours, the Porsche can have its tank refilled in a minute or two and be on its way. The electrically refreshed batteries in the Tesla will then begin another cycle of diminishing performance, while the gasoline in the Porsche’s tank will give it optimum performance to the last drop. For all its technological edginess, the Tesla is really just another example of why gasoline is still king. After all the promises of their yesterdays, electrics remain the cars of tomorrow because no battery or combination of batteries has duplicated the energy density of a gallon of gasoline.
Ethanol as a fuel—even when it is combined with 15 percent gasoline—delivers only about two-thirds the performance and mileage of a gasoline-powered car. As a fuel additive (10 percent of a gallon) it adds absolutely nothing to gasoline’s efficacy. Its main use is as an oxygenate, which may help reduce some emissions, but at the expense of overall performance and mileage. Indeed, gasoline could be formulated to meet federal pollution standards without the addition of ethanol by increasing its alkylate content. But ethanol, an old product anointed by a new political religion, has a lot of traction right now in Washington. It is mandated to “enhance” gasoline as well as the wallets of corn farmers. Even when burdened with ethanol, gasoline soldiers on.
We Americans drive our 210 million motor vehicles 7 billion miles and consume 390 million gallons of gasoline every day.
When we get over the latest panic about gas prices, we will still want to tow boats and take our families to the lake or drive to the amusement park, and it is very likely that we will be burning gasoline to get there. We will be burning it much more cleanly, much more efficiently. Internal combustion engines continue to increase in efficiency, and we can expect advances as technologies are refined in such areas as higher voltage electrical systems; on-demand rather than continuous power for steering; continuously variable transmissions; and more efficient engine breathing through more precisely controlled valving.
The cars we drive may be more Prius-like in one sense, mating the virtues of electricity and internal combustion, but they will very likely be larger and more powerful than a Prius. The cars of a decade from now may be more like the Mercedes-Benz F700 research car now being tested. It’s a big car, as big and roomy as the present S-Class Mercedes flagship sedan. The F700 can accelerate from 0 to over 60 mph in 7.5 seconds and has a top speed of 120 mph, but it averages 44 miles per gallon and has a very clean exhaust.
This experimental sedan’s secret is its “DiesOtto” concept. An electric motor incorporated directly into the car’s seven-speed automatic transmission is combined with a turbocharged four-cylinder gasoline engine, which, as AutoWeek Magazine has noted, incorporates both gasoline and diesel technology to “combine the power, smoothness and low emissions of a gasoline engine with the torque, flexibility and frugality of a diesel.” Mercedes says it still has a lot of refinement to do on this drive system, but the F700 plainly shows the possibility of a large, comfortable car that weighs almost two tons, produces 238 horsepower to move with alacrity, and yet gets exceptional gas mileage for its size.
We are now in a period of what renowned energy consultant and Pulitzer Prize-winning oil historian Daniel Yergin has called a “very fevered psychology in the oil market” concerning long-term oil supplies. But the market is only beginning to awaken to how much oil the Earth can still give up—at a price. This coming decade will be an exciting and challenging one in energy, filled with surprises. One of those surprises may be a breakthrough, at last, in energy storage for electric cars. But another surprise to some, and a more likely one, will be the degree to which gasoline—used more efficiently and burned more cleanly by ever-improving engines—continues to dominate personal transportation.
Ralph Kinney Bennett writes the Automobility column for The American. He last wrote for the magazine about the secrets of success for the best-selling cars of all time.
Image by Darren Wamboldt/Bergman Group.