Lightweight materials can help improve fuel efficiency, but they also add cost.

One case in point is carbon fiber, which is light and strong, but also expensive.

Now, a research firm partially funded by BMW--which uses large amounts of carbon fiber in its i3 electric car and i8 plug-in hybrid--claims to be on the verge of slashing this material's price.

ALSO READ: BMW Says It Will Triple Production Of Carbon Fiber For Electric Cars

MAI Carbon Cluster Management is making progress toward reducing the cost of carbon fiber by 90 percent, Bloomberg reports.

Klaus Drechsler--head of he German firm--said researchers are already about halfway toward achieving that goal.

2014 BMW i3 (German-market version), Amsterdam, Oct 2013

2014 BMW i3 (German-market version), Amsterdam, Oct 2013

Exactly how MAI will cheapen carbon fiber is unclear at the moment, but lower costs will almost certainly lead to increased use in cars.

Carbon fiber's strength and light weight have been exploited in race cars and high-end supercars, but the material's cost has kept it mostly out of the mainstream.

The average cost of carbon fiber in its raw form is estimated at $20 per kilogram (around 2.2 pounds), compared to less than $1 for steel.

MORE: Carbon Fiber In Cars: More Energy To Make, Lower Lifetime Emissions

The list of MAI's backers shows the amount of interest in lowering that price.

In addition to BMW, the firm is also funded by Audi, as well as airplane-maker Airbus and SGL Carbon--which currently has a joint venture with BMW to produce carbon fiber at a plant in Moses Lake, Washington.

That material is used in the carbon fiber-reinforced plastic (CFRP) body shells of the BMW i3 and i8 electric cars, keeping their weight down without compromising structural rigidity.

2015 BMW i8, test drive in greater Los Angeles area, Apr 2014

2015 BMW i8, test drive in greater Los Angeles area, Apr 2014

All production at Moses Lake is currently dedicated to the BMW i models--although BMW M performance models use carbon fiber parts, and have for sometime.

BMW has said it hopes to expand the use of carbon fiber beyond strictly green or performance models.

Its mainstream luxury models--including the 7 Series full-size sedan--are also being targeted for weight savings.

It hopes to cut up to 400 pounds from the 7 Series in an upcoming redesign using technology and materials currently being beta tested on the BMW i cars.

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