You may have seen it on a t-shirt: "40 is the new 30." But you may not have realized it applies to miles-per-gallon just as much as age.

While cars with EPA ratings of 30 mpg or more used to be considered in the highest ranks of fuel efficiency, now 40 mpg seems to be the new benchmark for non-hybrid compact car lines.

And Honda, long known for the small and fuel-efficient Civic compact sedan and coupe, will be right up there with the rest of the gang when it launches the new 2012 Honda Civic.

41 mpg highway, but you have to order it

Honda expects the Civic HF model to receive an EPA rating of 41 mpg on the highway cycle, it said. The current 2011 Honda Civic sedan with a 1.8-liter engine and automatic transmission is rated at 25 mpg city, 36 mpg highway.

2012 Honda Civic

2012 Honda Civic

Unlike Hyundai, whose 2011 Elantra is rated at 40 mpg highway for every model, only some models of the 2012 Honda Civic line cross the 40-mpg mark. Hyundai has challenged other makers to report their sales of models rated at 40 mpg or better.

Chevy, Ford Too

The 2011 Chevrolet Cruze Eco is rated at 42 mpg highway, and the 2011 Ford Fiesta subcompact can be ordered with an optional package that returns a 40-mpg highway rating. That leaves the best-selling compact car, the Toyota Corolla, lagging behind, along with the Nissan Sentra Versa. The all-new 2012 Ford Focus has not yet been rated.

After showing lightly disguised Civic sedan and coupe concepts at last month's Detroit Auto Show, Honda released some photos and details of the 2012 Civic late last week. The non-HF models are estimated to achieve 39 mpg highway ratings.

The 2012 Honda Civic will come with a 1.8-liter four, unlike other makers (specifically Chevrolet, with its Cruze compact) who use direct injection and turbocharging to deliver the same performance from smaller engines: just 1.4 liters in the 2011 Chevy Cruze.

2012 Honda Civic

2012 Honda Civic

Hybrid gets lithium-ion battery

There will also be a 2012 Honda Civic Hybrid model, estimated to achieve a combined rating of 45 mpg. The 2011 Honda Civic Hybrid is EPA-rated at 40 mpg city, 43 mpg highway, for a combined rating of 41 mpg.

The new Civic Hybrid model will be Honda's first to use a lithium-ion battery pack, which holds roughly twice as much energy per pound as the nickel-metal-hydride packs used in all previous Honda hybrids. (Honda gave no indication of whether its other hybrids, the Insight and CR-Z, will be upgraded to the new technology.)

The new Civic Hybrid will also use the 1.5-liter engine that's fitted to the 2011 CR-Z hybrid sports car. The engine is specially tuned to work in conjunction with Honda's mild-hybrid system, which adds a 15-kilowatt motor between engine and transmission.a

Both the new Civic HF and the 2012 Civic Hybrid will also have "aerodynamic components for improved efficiency," although Honda gave no specifics about what those would be.

2010 Honda Civic GX natural-gas vehicle, Los Angeles, November 2010

2010 Honda Civic GX natural-gas vehicle, Los Angeles, November 2010

Wider distribution for Civic GX

Honda also plans a third green Civic, the GX natural-gas vehicle (NGV) model. It has been the only carmaker to build and sell natural-gas vehicles for 10 years now.

The company plans to distribute its redesigned NGV more widely, making it available to specially-certified dealers in regions where natural-gas supplies are plentiful and retail distributors exist. Read our review of the current Honda Civic GX here.

While Honda said only that the cars would go on sale "this spring," it told its dealers that the new Civic models will start arriving at dealerships in April.



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