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Mazda to Show New Premacy Hydrogen RE Hybrid and Post-2010 Powertrain Technologies at Tokyo Motor Show

The Premacy Hydrogen RE Hybrid.

Mazda will show a new version of its Premacy Hydrogen RE Hybrid (earlier post), first introduced in 2005, at the Tokyo Motor Show this month. The company reiterated that it would begin leasing a version of the dual-fuel rotary-engine hydrogen mild hybrid in Japan in 2008. (Earlier post.)

Also on display at the show will be technical exhibits highlighting Mazda’s work on next-generation powertrains and safety improvements that are currently under development. In the decade following 2010, Mazda will revise its entire powertrain series to emphasize enhanced fuel and emissions performance combined with superior driving performance, the goal being to reach “Sustainable Zoom-Zoom”.

Compared with the Mazda RX-8 Hydrogen RE, the new Premacy Hydrogen RE Hybrid yields 40% better output, resulting in enhanced acceleration performance and an extended hydrogen-fueled range of about 200km (124 miles), or twice that of the RX-8 Hydrogen RE.

The layout of the hydrogen hybrid. Click to enlarge.

The hydrogen rotary engine is changed from a longitudinal to a transverse layout and its intake/exhaust resistance and combustion efficiency are improved to yield high output across a wide range of engine speeds. The new version features a li-ion battery rather than the earlier NiMH battery pack.

Plant-derived Mazda Biotechmaterial is used for interior plastic parts and seat fabrics to accelerate research and development for commercial use.

Next-generation powertrain technologies to be on display at the Tokyo show include:

Next Generation I-4 Direct Injection Gasoline Engine. With the next-generation 2.0L gasoline engine, Mazda is aiming for a 15% to 20% increase in dynamic performance and a 20% increase in fuel economy (in-company comparison with the current 2.0L engine). Mazda engineers are focusing on direct injection, combustion control, variable valve system technology and emission purification technology to reduce energy losses and raise thermal efficiency. Further, Mazda is developing a new catalyst employing single nano technology (earlier post) that simultaneously improves emissions-cleaning capability and reduces the volume of precious metal required in a 3-way catalytic converter.

Next Generation Clean Diesel Engine. The next-generation 2.0L diesel engine is targeted to deliver an improvement in fuel economy by up to 10%, while still meeting advanced global emissions requirements. Engineers are focusing on direct piezo-injection technology enabling multi-stage injection, reduction of the weight and size of every reciprocating and rotating component as well as the aluminum cylinder block. A two-stage turbocharger is adopted to yield both high torque in the low rev range and an increased acceleration response.

Next Generation RENESIS (Rotary Engine 16X). In developing the next-generation RENESIS, Mazda made a thoroughgoing revision of engine dimensions including the trochoid rotor housing, adopting a longer stroke and larger displacement of 1600cc (800cc x 2) aimed to raise thermal efficiency and boost torque at all engine speeds. Mazda is employing the Hydrogen RE design policy of a direct injection system and aluminum side housing, as well as various other measures to enhance the new RENESIS’ light weight and compact size.

SISS (Smart Idle Stop System). Mazda’s SISS restarts the engine without using an electric motor. (Earlier post.) The system injects fuel directly into the cylinders while the engine is stationary and ignites the fuel to create downward piston force that serves to start the engine, resulting in fuel savings of about 10% in Japan’s 10-15 mode in addition to restarting the engine quickly and quietly.



Mazda has always been great at building a competent vehicle for handling but their vehicles never get the best of fuel economy. I hope to see their new I-4 and SISS in the US soon.


A capacity increase of over 30% is what the Mazda wankel engine needs to increase power (up to 300 HP?) but especially torque of its RX8 and perhaps RX7 successors. And who knows what a turbocharged RX7 can do against the likes of Nissan GT-R, the Honda NSX successor and Lexus' mid engined super sportscar. Hopefully, advanced technology like DI can prevent a (much) further increase in fuel consumption...

Tom McRitchie

I am very anxious to see the Diesel/Hydrogen engine. I worked on the old wankel engines in the past and even with their problems they were great cars. I am presently driving a diesel one ton cummins with a hydrogen generator on it and have been able to average 24 miles per gallon and I love the power and economy. I'll be one of the first in line to see the new models.

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