Gasoline, Diesel, Hybrids And Plug-Ins: The Efficiency Leaders

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It's official: Cars really are getting more efficient.

Not that there isn't a long way still to go, but virtually every month statistics emerge to suggest the average fuel efficiency of vehicles in the U.S. has gone up another few fractions of a percent.

There are still winners and losers though, so we decided to think positive and look at the winners--just what are the most efficient gasoline, diesel, hybrid and plug-in vehicles available right now?

Gasoline: 2013 Scion iQ
36 MPG city, 37 MPG highway, 37 MPG combined

The 2013 Scion iQ sticks to a simple formula to achieve the gas mileage it does: A small, light body, a small-capacity gasoline engine, and that's about it.

Several regular gasoline vehicles beat the iQ's 37 MPG highway figure--40 MPG is now not uncommon--but with a continuously-variable transmission and 1.3-liter engine it fights back with strong city mileage.

The compact size makes it easy to drive in the city too, and even easier to park by the curb. Don't expect to take too many passengers though--it may be a four-seater by trade but you'll realistically fit no more than three, and you're better folding the rear seatback down and improving its luggage space.

Diesel: 2013 Volkswagen Passat TDI
31 MPG city, 43 MPG highway, 35 MPG combined

It's a Volkswagen-Audi washout at the top of the diesel charts, though that might change when the Chevrolet Cruze Clean Diesel and Mazda Mazda6 Sky-D both go on sale.

Until then, the Passat TDI is the most efficient diesel model you can buy, and it's a particularly excellent highway performer. It uses the same 2.0-litre TDI engine as every other VW and Audi of this size or smaller, and offers a surprising turn of pace and excellent refinement for a diesel.

Not a fan of the Passat's size or shape? Worry not--you can find the same engine, with barely lower fuel efficiency, in everything from the classy Audi A3, through the practical Jetta wagon, to the funky Beetle and Beetle Convertible models.

Hybrid: 2013 Toyota Prius C
53 MPG city, 46 MPG highway, 50 MPG combined

Both the Prius C and its larger, more iconic Prius stablemate achieve 50 MPG combined, and each offers slightly different strengths.

The Prius C is cheaper, naturally, but it's also a little more agile and even better suited to city driving, with the higher city EPA rating. The regular Prius is the more spacious, and its superior aerodynamics and larger engine help it manage better highway figures.

2012 Toyota Prius Plug-In Hybrid

2012 Toyota Prius Plug-In Hybrid

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Plug-in hybrid: 2013 Toyota Prius Plug-In
51 MPG city, 49 MPG highway, 50 MPG combined, 95 MPGe blended

The plug-in hybrid market is still relatively small right now, awarding the Prius top spot almost by default.

It's selling in modest numbers and doesn't really break any new ground, but based on the already-efficient Prius it's always going to be inexpensive to run, particularly when that 11-mile electric and gas blended mode is considered--over which the Prius achieves 95 MPGe.

Driving thrills aren't on the agenda, but the Prius should be trouble-free to own and relaxing to drive.

Electric: 2013 Fiat 500e
122 MPGe city, 108 MPGe highway, 116 MPGe combined

There are actually four answers to the question, "what's the most efficient electric car on sale?"

Technically, the 2013 Scion iQ EV is--at 121 MPGe combined, or just 28 kWh per 100 miles. Only you can't get one for love nor money, which is poor even by compliance car standards. The Honda Fit EV is next up at 118 MPGe combined, but while you can at least put one on your driveway, it's lease-only.

The 500e is the most efficient electric car you can actually buy and own, which is why we've awarded it the top spot. But if you wanted to go further, the 500e is still a compliance car and therefore only available to a very limited number of people--meaning the 115 MPGe, 29 kWh/100mi 2013 Nissan Leaf would actually come top. But for those who have access to one, it's the 500e that wins here. More fun than the Leaf, too.


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Comments (9)
  1. Prius does not compare to the Ford C-Max Energi. I compared them and bout the the C-Max. Since many will doubt what I am saying go out to your local Ford and Toyota dealers and test drive each car. You will see a huge difference and if you are buying I know you will but the C-Max.

  2. Unless you actually need real cargo room...... I bought the Prius Plug In because the Energi cargo space and accessibility/utility was a joke. Plus I take a lot of long trips where the 55+mpg without a charge is nice. Customers should check out the fuel site and input their actual driving mixture to figure out which car is most efficient for them. In my case the 2013 Volt was the most efficient followed by the PIP, then the 2011-2012 Volt then the CMAX Energi far behind.

  3. The Volt is a plugin hybrid; despite GM's efforts to make us think otherwise.


  4. Do you have an ax to grind here? I don't see Volt being mentioned anywhere in the article here...

    As far as your "definition" goes, let us just leave at that. I don't think GCR appreciate that I reply with 15 posts to explain my points. Keep your hate toward the Volt to yourself, okay? And don't being an EV-1 "sore loser"...

  5. Semantics. Since most people who own a BEV keep an ICE car as a backup for longer trips, they're essentially doing the same thing but with two cars instead of one. So if I drive 10,000 electric miles a year in my Volt, but you only drive 8,000 miles a year in your BEV because you can't take it on longer trips, then who has the moral high ground?

    They're all electric. Stop fighting your friends. The anti-ev crowd really enjoy it when you do.

  6. The Volt gets better gas milage than any of the cars in the article and it is not even mentioned. It appears this article is incomplete at best and most likely negligent in representing a limited subset of efficient cars.

  7. @Andrew: The Volt does NOT get better gas mileage than any of the cars in this article except the Passat TDI diesel.

    It is rated at 37 mpg combined in gasoline mode, equivalent to the Scion iQ, and roughly one-third lower than both the Prius C hybrid and the Prius Plug-In Hybrid at 50 mpg.

    It is also less efficient in blended mode (at 97 MPGe) than several plug-in hybrids, including both Ford Energi models (100 MPGe each) and the 2014 Honda Accord Plug-In Hybrid (115 MPGe).

    See here to confirm these figures:

    As for your charge that the article is "most likely negligent" ... RLY ?!?!? Try checking your numbers first.

  8. @John,

    You have failed to mention that those MPGe rating are "FAKE" b/c they don't take the range into consideration.

    Once you drive past the 11 miles test range, some of those shorter range MPGe number will drop significantly.

  9. I've owned a Chevy volt for 14 months. Lifetime mileage to date 108mpg. Profile is roughly 50/50 gas/electric. Routinely get 40 miles/charge, driving hard yields 37. Only charge at home, why bother when I'm out, have an engine. Had a 2011 Audi Q5, and a 2007 BMW 530i. Volts quicker and handles better than either one. I live in Newport Beach, CA, land of the image car. The Volt will handily beat the Porches, Benz's Ferraris, and other exotics in traffic, no contest. The Volts so quick, and SILENT, that for them to win they'd be pariahs belching noise and smoke, and if they delay at all, Volt wins no matter. You look normal (silent) they look stupid. 108mpg muscle car' you can romp on for free, wouldn't trade it for anything else.

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