Imagine it's 2025 and the full impact of tougher gas-mileage regulations has taken effect.

That year, it's easy to buy a mid-size sedan--perhaps even something a bit larger--that returns 40 mpg in regular use.

Here's the thing, though: For 2013, there are already a handful of sedans that do that.

We've recently tested a few hybrid sedans, and two of them--the 2013 Toyota Avalon Hybrid and the luxury 2013 Lexus ES 300h--showed 40.0 mpg (or a few tenths higher) on their dash displays.

We drove both on our usual test route, which is about two-thirds highway and one-third around-town usage.

And with better noise suppression than ever before, the cars mask the characteristic hybrid behavior--howling engine under hard acceleration--so well that some drivers may never know they're actually powered not only by a combustion engine but by an electric motor as well.

Your mileage may vary, of course, but these are hardly exotic cars: They're hybrid versions of high-volume sedans that sell in the tens of thousands every year.

The number of cars that do just that will grow in the years to come. Here's our list of this year's cars that get 40 mpg or higher.

2013 Ford Fusion Hybrid, test drive, Catskill Mountains, NY, Mar 2013

2013 Ford Fusion Hybrid, test drive, Catskill Mountains, NY, Mar 2013

(1) 2013 Ford Fusion Hybrid: 47 mpg combined

Ford has been under fire lately because the fuel efficiency of its C-Max Hybrid hatchback achieved by owners doesn't appear to match that car's 47-mpg rating--which it lowered to 43 mpg late Thursday.

The 2013 Fusion Hybrid sedan, so far, remains at 47 mpg, though many owners report lower averages under real-world conditions.

Nonetheless, it's safe to say that the Fusion Hybrid will return 40 mpg or close in most uses.

We achieved 36.8 mpg in a winter test drive, which would likely hit about 40 mpg in more temperate weather.

The 2013 Fusion Hybrid is also eligible for a software upgrade to boost its real-world mileage; the revised software will be used on all 2014 Fusion Hybrids as well.

2013 Lincoln MKZ Hybrid, New York City, June 2013

2013 Lincoln MKZ Hybrid, New York City, June 2013

(2) 2013 Lincoln MKZ Hybrid: 45 mpg combined

Using the same powertrain as the Fusion Hybrid, the heavier and more luxurious Lincoln MKZ Hybrid is rated lower, at 45 mpg.

It too is eligible for the software upgrade, but we haven't had a chance yet to test the MKZ Hybrid on our usual test route.

In a very short and atypical city drive, we got 26.8 mpg--but that was hardly a fair test, so we're not putting a lot of importance on that result.

This is a case where we're giving the MKZ Hybrid the benefit of the doubt. If we learn otherwise once we test it, we'll revise this article.

2012 Toyota Camry Hybrid

2012 Toyota Camry Hybrid

(3) 2013 Toyota Camry Hybrid LE: 41 mpg combined

Now we get to no fewer than three Toyota products: two mass-market sedans and a luxury Lexus.

The Camry Hybrid, which was Toyota's first non-Prius hybrid sedan starting in 2007, is rated at 41 mpg combined for the LE trim level and 40 mpg for the heavier, more luxurious XLE.

Toyota sells tens of thousands of Camry Hybrids every year. While you may not notice them on the street, our experience has been that they achieve close to their EPA-rated mileage.

2013 Lexus ES 300h

2013 Lexus ES 300h

(4) 2013 Lexus ES 300h: 40 mpg combined

We just tested a Lexus ES 300h, the new hybrid model of the mid-size Lexus sedan, this past weekend.

We haven't finished writing up the test report yet, but the car delivered an even 40.0 mpg over almost 300 miles of mixed driving.

And it did so with a level of noise suppression that all but camouflaged any hybrid personality.

We think that's a good thing for Lexus buyers.

2013 Toyota Avalon Hybrid, Catskill Mountains, NY, May 2013

2013 Toyota Avalon Hybrid, Catskill Mountains, NY, May 2013

(5) 2013 Toyota Avalon Hybrid: 40 mpg combined

Finally, there's the Avalon Hybrid--which we tested in May.

It too returned 40.2 mpg in our test, and we found it stylish, roomy inside, and unexpectedly pleasant as an all-around sedan.

Coming for 2014 will be the Honda Accord Hybrid, which may well earn a rating that puts it into this list as well.

Meanwhile, if you want to travel 100 miles on only 2.5 gallons of gasoline--$10, more or less--these are your options.

Your choices will only expand in the years to come.

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