It shouldn't be a surprise, but for 2012, new car models--and revisions to existing models--are all about the gas mileage.

Take Chevy, for instance. Yesterday it announced that the V-6 model of its 2012 Camaro two-door sports coupe (y'know, the one you can get with a really big, powerful V-8) would offer more horsepower and get a better highway gas mileage rating too.

Today we turn to the Cruze compact sedan. It already has a Cruze Eco option that delivers 28 mpg city, 42 mpg highway when outfitted with the six-speed manual transmission.

Now, for 2012, Chevy has bumped the highway mileage rating of the Cruze model with 1.4-liter engine and automatic transmission to 38 mpg, a gain of 2 highway mpg over last year's EPA ratings of 24 mpg city, 36 mpg highway for that same combination.

It still doesn't quite get the 2012 Cruze up to the magic 40-mpg highway mileage level. For that, buyers still have to order the special extra-cost Eco model.

The company got the increase, according to the specs sheets, by lowering the final-drive ratio to 3.53 from 3.87 in the current year's model. That means the engine is running at a lower speed for any given road speed, and hence burning less gasoline.

The downside? Acceleration and response times may increase slightly. We'd have to drive a 2011 and 2012 Cruze side-by-side to determine whether that performance hit is perceptible to everyday drivers.

45th Anniversary Edition 2012 Chevrolet Camaro

45th Anniversary Edition 2012 Chevrolet Camaro

Chevy has also expanded availability of the six-speed manual transmission to more Cruze trim levels.

This means "you can now have a fun manual transmission" without, sneers the website Cheers and Gears, "all that greenie-weenie stuff included on the Eco."

As for the 2012 Camaro, the changes are more extensive than the taller axle ratio in the 2012 Cruze.

Chevy actually designed a new cylinder head for its 3.6-liter direct-injected V-6 engine, which integrates the exhaust manifolds right into the aluminum head castings. The pair of heads together is 13 pounds lighter, more compact, and gives better airflow.

The result is 11 more horsepower--taking the V-6 to 323 hp for 2012--as well as a 1-mpg increase in the highway rating from 29 to 30 mpg. Not bad for a car that large (on the outside, anyway).

[2012 Chevrolet Cruze Online Ordering Guide via Cheers and Gears]


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