General Motors new Hydra-Matic 6T70 six-speed automatic transmission, an advanced transmission with clutch-to-clutch shift operation for front- and all-wheel drive vehicles, will make its debut in the new 2007 model year Saturn Aura midsize sedan.

Go deeper with GlobalData

Data Insights

The gold standard of business intelligence.

Find out more


Co-developed with Ford, the new six-speed joins the already announced Hydra-Matic six-speed rear-wheel drive family of automatics and Allison 1000 six-speed automatic as part of GM’s plan to produce three million six-speed automatics annually by 2010.


The 6T70’s clutch-to-clutch operation allows for reduced complexity and compact packaging. A wide, 6.04:1 overall ratio spread helps the transmission deliver both performance and fuel economy, enabling up to 8% improved performance and up to 4% improved fuel economy when compared with current front-wheel drive four-speed automatics.


The joint development effort between Ford and GM allowed both companies to maximise time and engineering talent to answer a common need for a fuel-efficient transmission that meets the performance needs of high-output, transverse-mount powertrains.


Co-development of the transmission allowed it to reach production in less time and enabled each company to reduce development costs by as much as 50%. A common design and many common components are shared between GM and Ford six-speed variants, but each company developed its own controls and calibrations to tailor the shift feel of the transmission to fit their brand characteristics.

How well do you really know your competitors?

Access the most comprehensive Company Profiles on the market, powered by GlobalData. Save hours of research. Gain competitive edge.

Company Profile – free sample

Thank you!

Your download email will arrive shortly

Not ready to buy yet? Download a free sample

We are confident about the unique quality of our Company Profiles. However, we want you to make the most beneficial decision for your business, so we offer a free sample that you can download by submitting the below form

By GlobalData
Visit our Privacy Policy for more information about our services, how we may use, process and share your personal data, including information of your rights in respect of your personal data and how you can unsubscribe from future marketing communications. Our services are intended for corporate subscribers and you warrant that the email address submitted is your corporate email address.

Rated for engines up to 315 horsepower and 280 lb.-ft. of torque, the 6T70 helps maximise powertrain performance and economy through its wide 6.04:1 ratio – the spread in gear ratios between first gear and sixth gear. This configuration allows for a ‘steep’ 4.48:1 first gear, which helps deliver exceptional launch feel, and a 0.74:1 overdrive sixth gear – the ‘tall’ overdrive gear lowers rpm at high speeds, reducing noise, vibration and harshness. Fifth gear is 1:1 or direct drive.


Shorter steps between the gears, compared with a four-speed automatic, enhance performance and feel, as the transmission quickly finds the best gear for the vehicle speed and road conditions – there’s less “hunting” (shift busyness) on grades, for example. Also, the 6T70 offers the capability of driver shift control (DSC), which allows the driver to use tap-up, tap-down shifting to select the desired gear for specific road conditions, such as driving up a steep hill.


The Hydra-Matic 6T70 will be manufactured at GM’s Warren Transmission plant from summer 2006, when production of the Saturn Aura begins.