Compact Vehicle Starter optimizes fuel efficiency.

Press Release Summary:

Compact, lightweight starter features pinion shift mechanism that separates clutch and pinion, so only pinion needs to engage with engine ring gear. This allows for compact switch part because little power is needed to move engaging component of starter. Suitable for compact cars powered by gasoline engines of 660-1,200 cc displacement, starter offers simplified installation in engine compartment and, being low-weight, also optimizes fuel efficiency.

Original Press Release:

DENSO Develops One of the World's Lightest Starters for Compact Vehicles

- Approximately 40 percent lighter than the conventional product -

KARIYA (Japan) - DENSO Corporation has developed one of the world's lightest starters for small, compact vehicles. The new starter, which is about 40 percent lighter than a conventional starter, finds its first application in the MR Wagon launched by Suzuki Motor Corporation in Japan earlier this month. DENSO's starter allows for easier installation in the engine compartment and the reduction in weight also helps increase fuel efficiency.

"Since early in its inception, DENSO's challenge has been to make its products smaller and lighter. Sometimes this is easier said than done. Because starters operate only when the engine is cranked, the greatest technical challenge has been to reduce their size and weight," said Masahiko Miyaki, senior executive director responsible for DENSO's Electric Systems Business Group. "DENSO has overcome this challenge and dramatically reduced the weight of this new starter by using an innovative pinion shift mechanism that separates the pinion and overrunning clutch."

The traditional approach to reducing a starter's size and weight was to downsize the internal motor. The other parts such as the driving part - consisting of an integrated clutch and pinion which engages with the engine ring gear - and the switch part - needing certain power to shift the driving part towards the ring gear - have not seen significant reduction in size and weight.

For the new starter, DENSO developed a pinion shift mechanism that separates the clutch and pinion so only the pinion needs to engage with the engine ring gear, whereas in conventional starters the integrated clutch and pinion needed to be shifted toward the ring gear to engage. With this new mechanism, the switch part was made lighter and smaller because less power was needed to move the engaging part. As a result, the overall product weight is approximately 40 percent lighter compared to the conventional product.

The new starter can be used for compact cars powered by gasoline engines of 660 to 1,200 cc displacement. In addition to this product, DENSO has developed a starter, which is about 30 percent lighter than existing ones, for vehicle engines of 1,200 to 2,500 cc. DENSO aims to produce a total of 5 million units of both models a year, and sell them in China, Thailand, Brazil, India, and other compact gasoline vehicle markets.

DENSO's been developing starter motors for the last 50 years and continues to be the largest starter motor supplier in the world - with about 20 percent market share. In addition to conventional starters, DENSO develops and produces starters for start/stop systems whose market is expected to grow because of their contribution to increased fuel efficiency. Through these developments, DENSO will continue to help improve vehicle fuel efficiency. DENSO Corporation, headquartered in Kariya, Aichi prefecture, Japan, is a leading global automotive supplier of advanced technology, systems and components in the areas of thermal, powertrain control, electric, electronics and information and safety. Its customers include all the world's major carmakers. Worldwide, the company has more than 200 subsidiaries and affiliates in 34 countries and regions (including Japan) and employs approximately 120,000 people. Consolidated global sales for the fiscal year ending March 31, 2010, totaled US$32.0 billion. Last fiscal year, DENSO spent 9.1 percent of its global consolidated sales on research and development. DENSO common stock is traded on the Tokyo and Nagoya stock exchanges. For more information, go to, or visit our media website at

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