Add Delphi to the companies investing in Silicon Valley startup Tula Technology’s cylinder-deactivation powertrain control software as a cost-effective method of improving fuel efficiency in all types of gasoline engines.
Delphi joins GM Ventures, General Motors’ investment arm, and venture-capital firms Sequoia Capital, Sigma Partners and Khosla Ventures in taking a financial stake in Tula. Tula was founded in 2008 by India-born Adya Tripathi, an inventor whose previous work centered on developing better microchips for audio amplifiers.
Tula represents a significant departure for the inventor, focusing on developing software to precisely control the operation of an internal-combustion engine via continuously variable cylinder deactivation called Dynamic Skip Fire (DSF).
Unlike conventional cylinder-deactivation technology, where a fixed number of cylinders are shut down under a relatively rigid set of conditions, DSF continuously makes firing decisions on an individual cylinder basis to deliver the required engine torque for all vehicle speeds and loads while avoiding vibration issues.
Delphi Chief Technology Officer Jeff Owens says DSF has shown a fuel-efficiency improvement of up to 17% in an 8-cyl. engine compared with one without cylinder deactivation. The technology also works in smaller engines, with efficiency gains in the 10% range for 4-cyl. powerplants.
“We think this is a lever the automakers will pull and pull hard, starting now,” Owens says at a presentation at Delphi’s headquarters in Auburn Hills, MI, previewing the company’s message for the upcoming Frankfurt auto show. “This is a game-changing technology.”
DSF also could be applied to hybrid powertrains to improve engine efficiency by using EV power to smooth engine operation, allowing for cylinder deactivation at idle, says Jim Zizelman, Delphi managing director-powertrain. DSF now is in development for specific product applications due on the global market by 2020, he says.
In a brief test drive of a DSF-equipped GMC Yukon Denali, the V-8 system operates seamlessly; if not for a computer screen showing engine performance and cylinder deactivation, it would have been undetectable as various cylinders in the V-8 fired or dropped out of operation.
DSF comes as automakers speed up powertrain investment to meet tightening global fuel-economy and carbon-dioxide emissions rules, including a federal target of 54.5 mpg (4.3 L/100 km) by 2025 in the U.S. Owens says even though consumer demand for fuel-efficient vehicles might wane with plummeting pump prices, DSF still can play a part in helping automakers meet global emissions regulations.
DSF has the potential to meet those targets at a cost of about $30 per percentage point of fuel efficiency achieved, compared with current technologies such as turbocharging and direct injection that cost up to $100 per percentage point, notes Tula CEO R. Scott Bailey, a former Delphi executive.