Fuel-Sipper Smackdown 4: Which Car Gets the Best Fuel Economy?

The Country Highway Route

Our first leg took us the extra-long way from Fontana, California, to Las Vegas, through Death Valley. These were lonely and occasionally very weird rural highways, and we traveled state highways with speed limits of 50 and 60 mph. This has been the best-case scenario for highway fuel economy in the past. But not this time.

Perhaps these results indicate that manufacturers are learning to tune their cars to achieve higher numbers in the revised EPA testing enacted in 2008 — numbers that have even less to do with real-world driving than before. Or maybe the Fiat is just that good.

The City Route

So if you take a Chevy Volt on a road trip, where do you charge it? Well, our Volt got a full load of electrons thanks to the EV Charge America charger installed at the Flamingo Las Vegas. The Flamingo is one of only a few hotel properties in Vegas to offer such a service (the Mandalay Bay and Luxor being the others). The Flamingo is a pioneer to be sure, and its staff actually painted the green lines with an "EV CAR" label around our car in the designated charging spot the night before we left on our 180-mile city driving loop around the greater Las Vegas area.

As for the city drive itself, the Volt took the crown with a gasoline-only average of 33.7 mpg. This was the best mpg on this leg, even without the benefit of its 44.3 miles of electric-only cruising range on this loop (its mpg for this leg would have been 44.8 mpg with the electric running factored in). Of course, if you keep your daily city driving below 44.3 miles (a good possibility), you'll be paying less for electricity. How much, exactly? Well, it cost approximately $1.50 in electricity to travel 44.3 miles in the Volt, whereas it costs $3.89 in gasoline to go 33.7 miles. The cost savings for electricity would certainly add up.

The Kia Optima Hybrid disappointed once again, its fuel efficiency falling below its EPA estimate of 35 mpg, but 2nd place is nevertheless still 2nd place. The other three cars were essentially competing among themselves. While the Elantra fell short of its estimate of EPA city mpg by about 1 mpg and the Jetta pretty well nailed its number of 30 mpg, the Fiat 500 once again proved to be an overachieving fuel-sipper. With prudent shifting of its five-speed manual transmission, we found the 500 capable of achieving 31.3 mpg in the city without forcing us to drive like a total grandma.

The Interstate Highway Route

This final 210-mile leg from Las Vegas to Fontana along Interstate 15 was not only more straightforward from a logistics standpoint but also more straightforward when it came to mpg rankings. The results were ordered just like the city loop, except the Elantra and 500 flip-flopped.

But here's a question: What if we couldn't have recharged the Volt? Well, the Volt would have achieved only 39 mpg, so it would've ceded its crown to the Jetta TDI. Yet we did charge up the Volt at the Flamingo, and the car managed 31.7 miles before firing up the gasoline engine. Unlike the first leg up Cajon Pass, I-15 out of Las Vegas is largely flat, more indicative of a regular strip of American freeway. We expect the Volt to get this sort of range on the average highway.

Once again, however, every car here managed to miss its EPA highway mpg number with the exception of the Fiat 500 (at least when you round up, as the EPA does).

The Final Cost

So who wins? Well, in terms of mpg, then the Chevrolet Volt takes the rest of the pack to school (as long as you're able to recharge its battery, of course). In terms of overall cost, the Chevy Volt still wins, but there's only a $2.33 difference between it and the last-place Jetta TDI.

The Volt would've been cheaper to run if its engine achieved better fuel economy or ran on regular gas; the use of 87-octane gasoline would've given it a victory of $7.66 instead of just 22 cents. Still, apart from its fuel sipping, the Volt is a nice car to drive. Even when its all-electric charge runs out, the gasoline engine is less noticeable than in a Prius, while the Chevy's sophisticated ride, comfortable seats and well-appointed cabin set it apart from the rest, especially during our lengthy rural route through the desert. Two of our editors picked it as their favorite car, even though they admitted that buying one didn't make financial sense.

The biggest surprise here is the 2012 Fiat 500. It is the only car here to have met or exceeded its EPA mpg estimates on every leg in the test, beating cars that should theoretically have been more efficient. With a simple combination of tiny size, tiny engine and manual transmission, the Fiat managed to prove only 22 cents more expensive to run than the ultra-complex Volt (not to mention about $20,000 cheaper to purchase). Of course, not everyone can live with such a tiny car, but the 500 feels like a real car to drive, even if it might not look like one.

The Kia Optima Hybrid is a significant disappointment given the disparity between its EPA mpg estimates and our real-world results. Still, the advantage the Optima has in running 87-octane gasoline lands it in 3rd place. Its good looks, practical sedan packaging, spacious interior and ample feature content led one of our editors to pick it as his favorite. Of course, the same attributes apply to the regular, more affordable Kia Optima, which nearly matches the Hybrid's fuel economy, so we'd buy one of those instead.

The Hyundai Elantra came close to its EPA estimate in the city, but fell far below its lofty 40-mpg target on both our highway legs. Yet, of all the cars here, the Elantra is the most "normal." It runs on regular gas, it has a spacious sedan interior and it doesn't rely on power-sapping Eco buttons (like the Optima) or overly conservative transmission programming (like countless other cars) to achieve its thriftiness. Perhaps if the Elantra used such fuel-saving tricks it would produce better EPA numbers, but then it would be worse to drive, and that would be a shame. The Elantra is one of the best compact sedans on the road, 40 mpg or no.

Finally, the trusty Volkswagen Jetta TDI brings up the rear because diesel fuel is a good 10 cents per gallon more expensive than premium at the moment. In a year, diesel could be cheaper or a buck pricier; you just never know. What we do know is that the diesel-powered VW Jetta is one of the simplest ways to save fuel, and the car has one of the lowest price tags. We're not especially keen on the Jetta sedan's recent redesign, but two of our editors still picked the TDI as the car they'd happily take home (even if they'd pay a few cents more to get there).

In the end, this test showed us three things. First, figuring out just how thrifty the 2012 Chevrolet Volt is requires a mathematician and a whole lot of perspective. Second, carmakers seem to be figuring out how to maximize results in the EPA test, so when you compare your car's real-world fuel economy with its EPA ratings, well, your mileage may vary, as the expression goes. And finally, this fourth Fuel-Sipper Smackdown has shown us that it's never been easier to find a car that will roll out of your driveway and get really great fuel economy.