GM will put new 8-speed in several truck models

Toledo-built transmission boasts higher efficiency

GM will use a new, more-efficient transmission in trucks.

General Motors Co. announced Friday that some high-horsepower versions of the company’s 2015 full-size trucks will be equipped with the company’s new eight-speed automatic transmission.

That transmission will come from GM’s Toledo Transmission Plant, where the company has invested $260 million over the last three years for new equipment and tooling to build the fuel-efficient transmission.

GM said the transmission will be standard on Chevrolet Silverado, GMC Sierra, and GMC Yukon Denali models equipped with the company’s 420-horsepower, 6.2-liter V-8 engine. The engine comes standard on top-trim-level trucks and is an available option on some other trim levels.

The pickup trucks are the second vehicle GM has confirmed for the transmission.

Earlier this year, the company announced the eight-speed would first go to the high-performance 2015 Corvette Z-06. At the time, company officials said the transmission was designed specifically with that vehicle in mind, though it would be versatile enough for other applications. GM has since confirmed the transmission will be available across the Corvette line next year.

GM spokesman Tom Read said the transmission housing will be slightly different for the pickup trucks, and it will be tweaked to deliver power to four wheels instead of just two, but essentially the mechanics of the gearbox are unchanged from what goes into the Corvette.

“There should be improved efficiency,” in the trucks, Mr. Read said. “You have a wider range of gears, and the idea is to run at lower engine speeds when you have a chance to.”

The company said fuel mileage estimates would be released later this year. The 2014 Silverado, which uses a six-speed automatic transmission, is rated at 15 mpg in the EPA’s city cycle and 21 mpg on the highway.

In the Corvette, GM said it expects a 5 percent gain in fuel efficiency by switching from a six-speed to the eight-speed.

Company officials have previously said they expect to use the eight-speed in a number of vehicles but haven’t identified any. Asked if it was possible the transmission would be used in other GM pickups, Mr. Read was vague.

“We haven’t announced anything yet, but there’s certainly opportunities,” he said.

GM has been fairly quiet about when full, normal production of the eight-speed would begin in Toledo, but union officials have recently said the plan is to begin by the end of this month.

The pickup trucks are expected to be available in the year’s fourth quarter.

Contact Tyrel Linkhorn at tlinkhorn@theblade.com or 419-724-6134 or on Twitter @BladeAutoWriter.