40 mpg compact sedan comparison
It's a powerful number -- 40 mpg. Car engineers do sophisticated analysis to figure out how to reach it, and the numerical game often comes down to just getting to the threshold where the number rounds up to 40.
It just so happens that we're practiced at rounding up, too -- in this instance, rounding up six significant examples of this rarified 40-mpg breed to determine if any of them are also cars you'd be happy to own.
The select six we've summoned to our investigation are the Chevrolet Cruze Eco (28/42), Ford Focus SFE (28/40), Honda Civic HF (29/41), Hyundai Elantra (29/40), Mazda3 (28/40), and Volkswagen Jetta TDI (30/42). A diesel, but no hybrids? Unlike the public's uneasiness with battery-aided driving (hybrid sales have been stuck around the 2.5-percent range), diesels are hydrocarbon kissing-cousins to their gasoline brethren. We know them. We're comfortable with them. And we were also curious to see how the Jetta TDI stacks-up against its high-tech gasoline alternatives.
In search of 40-mpg answers, we drove from our El Segundo nerve center to the high desert north of Los Angeles and two destinations we normally visit for our Car of the Year programs. At the first, we grunted our way through a zillion mind-numbing laps of the Hyundai-Kia Proving Ground's 6.4-mile oval in a sequence of stepped, constant speeds to establish our fleet's steady-state fuel-efficiency.
The next day, each car was repeatedly piloted around our familiar Tehachapi real-world driving loop, a richly informative 27.3-mile mix of small-town stop-sign streets, curvy rural roads, elevation changes, and freeway miles. (Another plus is that it's 80 miles from Los Angeles' super-saturated roadways, which are ever on the brink of cardiac arrest.)
Let me explain the meaning of the results you'll see on the following pages. Each car's average Tehachapi mileage, and fuel cost per mile doing so, are obvious. But we've added a figure to this that represents how depressed this is compared with these lap's theoretical mpg modeled from our constant-speed mileages -- that is, what they'd ideally do were they unimpacted by accelerating, fidgeting with the throttle, hill-climbing, and stopping. If you don't drive, uh, very gingerly, pay attention to this one.
Testing the Car's Mileage -- and Our Patience
Measuring things like 0-60-mph times and panic stops is old hat for us. But discerning fuel mileage, that's another issue. At a cruise-controlled 60 mph, one of our cars, the Chevrolet Cruze Eco, returned 49.4 mpg. That's 0.0202 gallon per mile, or, if you were to picture that gasoline as a series of teaspoons, one burned every 4 seconds.