Honda and General Motors may expand their cooperation on green cars, according to a report in the Japanese media.

In 2013 the two automakers signed a partnership to develop hydrogen fuel-cell powertrains, which remains in effect until at least 2020.

Now, it appears they may collaborate on plug-in hybrids as well.

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The two companies "have entered final negotiations" on an expanded partnership that would include plug-in hybrid development, reports The Yomiuri Shimbun (via Charged EVs).

At the moment, each maker uses its own two-motor hybrid and plug-in hybrid technology--and the two are differently arranged inside, with Honda's system nesting one motor inside the other, while GM's connects two separate motors with planetary gears.

A goal of the partnership is to lower production costs by jointly negotiating with suppliers, and to pool resources to better compete with other carmakers, the report said.

2016 Cadillac CT6

2016 Cadillac CT6

Honda and GM also reportedly expect collaboration to shorten development times of plug-in hybrid powertrains.

The Japanese firm expects to gain insight from GM, which it views as more experienced in the field. And GM expects the partnership to give it a competitive advantage over other automakers in the plug-in hybrid segment.

It plans to launch its Cadillac CT6 plug-in hybrid luxury sedan before the end of this year, using an adaptation of the 2016 Chevrolet Volt powertrain that is also used without a plug in the 2016 Chevy Malibu Hybrid.

MORE: Honda Clarity On Sale Late In 2016; Plug-In Hybrid To Get 40 Miles Of Range (Nov 2015)

Honda, meanwhile, is developing a dedicated plug-in hybrid model that may reach a larger audience.

After retiring the low-volume Accord Plug-In Hybrid, the company committed to launching a new model on a dedicated platform in 2018.

It has withdrawn the conventional hybrid version of its Honda Accord from the U.S. for a year; it is expected to relaunch for 2017 with an updated and even more efficient version of Honda's two-motor hybrid system.

2014 Honda Accord Plug-In Hybrid

2014 Honda Accord Plug-In Hybrid

Honda's plug-in hybrid will use the same platform as that used by the 2017 Clarity Fuel Cell. It's possible the plug-in hybrid will simply be another variant of that model.

Honda has said the new plug-in hybrid will have "more than triple" the Accord's electric driving range of 13 miles, which would mean a range of at least 39 miles on battery power.

Honda also claims the new two-motor hybrid system will offer more usable high-speed operation than the Accord plug-in, which had a top speed of 80 mph in electric mode.

The Honda plug-in hybrid may also share its platform with a battery-electric model, also slated to launch in 2018.

Honda hasn't discussed this electric car since announcing it almost a year ago, but it is thought that it will share the Clarity platform as well.


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