|The 4-cylinder compressed air engine. Click to enlarge.|
Tata Motors, India’s largest automobile company, has signed an agreement with MDI (Moteur Developpment International) of France for the application in India of MDI’s compressed air engines. MDI has already applied its CAT (Compressed Air Technology) engine in a prototype city car, the MiniCAT.
The agreement between Tata Motors and MDI envisages Tata’s supporting further development and refinement of the technology, and its application and licensing for India.
MDI has for many years been engaged in developing environment-friendly engines. MDI is happy to conclude this agreement with Tata Motors and work together with this important and experienced industrial group to develop a new and cost-saving technology for various applications for the Indian market that meets with severe regulations for environmental protection. We are continuing the development with our own business concept of licensing car manufacturers in other parts of the world where the production is located close to the markets. We have also developed this new technology for other applications where cost competitiveness combined with respect for environmental questions has our priority.—Guy Negre, founder MDI
The core of MDI’s work is a piston engine powered by the expansion of compressed air. MDI has developed two versions: a single fuel engine that relies solely upon compressed air, and a dual-fuel version that uses compressed air and a combustible fuel. When running under 50 kph (31 mph) in urban areas, the engine runs on air. At speeds greater than 50 kph, the engine switches to fuel mode. In this mode, the on-board compressor also refills the compressed air tanks.
The current production version of the compressed air engine applied in the MiniCat is a four-cylinder, 800cc unit that uses a boxer design. A proprietary connection rod allows the retention of the piston at top dead center during 70° of crankshaft rotation—providing enough time to establish the required pressure in the cylinder.
Tata Motors has more than 4 million Tata vehicles on the road in India, and is the leader in commercial vehicles and the second largest in passenger vehicles. It is also the world’s fifth largest medium and heavy truck manufacturer and the second largest heavy bus manufacturer.