CLEVELAND, Ohio -- A reviewer tested the fuel economy of Ford's 2013 Fusion hybrid sedan and came up with 27 miles a gallon. Another tester got 32 mpg.

A third, trying to max out the mileage, let the Fusion coast into his driveway and got 46 mpg from the car. That's still slightly less than the 47 mpg the Environmental Protection Agency says the car should get.

One car, a huge range of results on fuel efficiency in real-world driving.

Welcome to the future of fuel economy where the numbers the government says cars should achieve differ greatly from what you'll actually get.

Car companies are pushing new technologies to get top scores in government testing. But automotive experts say matching those numbers in the real world can be impossible.

"We all drive differently, and no one drives like the EPA," said Larry Dominique, an analyst with consumer research site TrueCar.com and a former design chief for Nissan.

How we drive

The basic advice on how to drive efficiently hasn't changed in 80 years: Don't slam down the accelerator when the light turns green, avoid stop-and-go driving when possible and maintain a constant cruising speed when you're on the highway.

"With a Ford Focus [compact car], you might get one driver who's very economy focused. Then you might get a younger buyer who wants to drive more aggressively," said Eric Fedewa, an analyst with consulting and research company IHS Automotive in Detroit. "Each of those drivers is going to get radically different numbers."

Last month, Ford product development chief Raj Nair defended the Fusion from fuel economy complaints by Consumer Reports. The magazine had found the hybrid got 39 mpg, 17 percent less than what Ford had advertised. Nair said driving at 75 miles an hour instead of 65 mph cuts efficiency by 15 percent.

The company's hybrids, he said, are "more sensitive to spirited driving and environmental conditions."

With newer technologies, getting great fuel economy becomes even more complicated.

Hybrids, such as the Prius and the Ford Fusion, are at their best in the worst driving conditions -- slow, stop-and-start driving. Electric motors take over, keeping the gasoline engine from revving and wasting fuel.

Except when it's cold.

In freezing weather, hybrids run their gasoline engines more to generate heat for the driver and because cold batteries don't work as well. According to Nair, cold weather can cut fuel economy by another 10 percent or so.

Cars with small turbocharged engines, such as Ford's EcoBoost models or General Motors' Lordstown-built Chevrolet Cruze, tend to get awful fuel economy in start-stop driving and excellent numbers when cruising at highway speeds.

So the fuel economy you're going to get will depend greatly on where you drive. If you commute to downtown from Shaker Heights on city streets, a carefully driven hybrid will probably give you the best fuel economy. But if you're in Westlake and commute on the freeway to Medina, a turbocharged car may be more efficient.

"Even in the same geographic location, the difference between one driver and another is fairly wide," Fedewa said.

Finding the right match

The problem with cars failing to hit EPA standards in real-world driving has been building for years. Dozens of customers sued Honda in 2006, saying they never reached EPA's 42 mpg estimates on the Civic hybrid. Toyota's Prius c missed targets by 22 percent in Car & Driver magazine's tests.

It's not just hybrids. The Cruze Eco got 29 miles per gallon in Car & Driver testing, missing the EPA target by 12 percent. In Motor Trend magazine's tests, the 2013 Honda Accord missed targets by 13 percent.

Car companies have to continue introducing more efficient models to meet upcoming fuel economy standards and because customers are demanding more miles per gallon. But they're going to have a lot of angry customers if they continue selling cars that only get great fuel economy in federal tests.

At Hyundai and its Kia subsidiary, keeping customers happy is going to cost more than $400 million.

The companies announced in November that they had misreported efficiency numbers to the EPA, allowing them to claim 36 mpg ratings on cars that only got 30. On Friday, Kia said it had set aside $187 million to reimburse customers for the difference between their fuel expenses and what they should have paid if the cars had performed as advertised. Hyundai has set aside $225 million.

TrueCar's Dominique said car companies are going to have to spend more time with their customers in order to find the right match between fuel-sipping technologies and driving styles.

"It's going to be more important for consumers to realize what their driving cycles are," Dominique said.

Fedewa called handling customer expectations "one of the major issues of the next decade."

Testing pickup buyers

One market where car companies have done a decent job of matching technologies to drivers is big pickups.

Ford says its Brook Park-built EcoBoost engines save more gas because the turbocharged V-6 trucks use less fuel in typical day-to-day driving.

GM says its V-8 engines that shut off cylinders when they're not needed are better because they burn less fuel than turbocharged V-6s when you're towing heavy loads while driving uphill.

"Duty cycle is a big determination of which vehicle is right for you," Nair said during an interview at the North American International Auto Show in Detroit this month. "We actually have to ask [buyers] probing questions about how they drive and then talk to them about the advantages of EcoBoost."

While the Ford executive would never recommend one of GM's pickups, Nair said dealers do tell some drivers they need V-8 engines. While the EcoBoost engine can handle the loads, a bigger engine can sometimes do so more efficiently.

That could be the next step for all consumers - probing questions from car dealers that go beyond color options and what it will take to get you to drive this car home today.

Dominique said companies are going to have to try new sales techniques and marketing efforts to go along with new fuel-saving technologies.

"Fuel economy is going up. The cars are getting better," Dominique said. "But the companies have to do a better job of telling people how these things work."