One of the factors making higher gas mileage possible across pretty much any vehicle on sale these days is multispeed transmissions.

At the dawn of this century, four-speed automatics were the standard; now it's six speeds--and eight-speed automatics are coming on strong.

Future models of the Chevrolet Silverado and GMC Sierra pickup trucks will get an all-new eight-speed automatic that GM has just introduced in a somewhat more glamorous package.

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The 2015 Chevrolet Corvette now uses GM's new eight-speed automatic with all versions of its various V-8 engines, unless you order a six-speed manual gearbox..

According to an article in trade journal Automotive News (may require subscription), that transmission will arrive in the company's full-size pickup trucks this year, in 2015 models fitted with the 6.2-liter V-8.

2014 GMC Sierra 1500

2014 GMC Sierra 1500

It will likely migrate into other V-8 versions over the next year or two.

The two Chevy and GMC pickups were redesigned for the 2014 model year, one year before the launch later this year of the redesigned 2015 Ford F-150.

That truck has attracted huge attention for a weight reduction of perhaps 700 pounds (depending on specfiication) due to its aluminum body and pickup bed.

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It's all in the service of meeting steadily increasing corporate average fuel economy (CAFE) rules between now and 2025.

GM is expected to introduce an all-aluminum pickup too, but not until 2019 or thereabouts.

And eight speeds is hardly the end of the gear race for the big GM trucks.

Ford and General Motors together are developing a 10-speed automatic for use in their largest rear- and all-wheel-drive vehicles, which will first be seen in some trucks in roughly two years.

Ten speeds seems only logical when even compact crossovers--the new Jeep Cherokee, for instance--now use nine-speed automatics as their standard transmission.


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