Research Project

Small, Low Cost High Efficiency Vehicles and Future Urban Transport

Dinesh Mohan, Geetam Tiwari, Sudipto Mukherjee and Anoop Chawla

Project Details






            Ever since the appearance of the automobile in the beginning of the 20th century, almost all transportation planning and vehicle design was done only with the objective of increasing speeds and reducing congestion on our roads. By the beginning of the 21st century three more concerns were added: depletion of oil resources within 15 – 30 years, unhealthy pollution levels in urban areas, and rising road traffic injury and death rates.


            The release of the Intergovernmental Panel on Climate Change (IPCC) report in 2008 has changed the ground rules further.  According to one scenario, in order to limit the average increase in global temperatures to a maximum of 2.4°C, CO2 emissions would need to peak by 2015 at the latest, and fall between 50% and 85% below 2000 levels by 2050. This will require a major reduction in emissions from the vehicle fleet, reduction in use of personal transport and modification in our behaviour to reduce number and length of trips. According to the International Energy Agency, India will overtake Japan before 2025 to become the world’s third-largest net importer of oil, after the United States and China. This will put tremendous pressure on us to start reducing fossil fuel energy consumption by motor vehicles before 2015.


            The implications of the IPCC report are at one level very simple – if the human race has to survive it has to limit CO2 emissions in a very short time. For us in India, it means that while the poorer sections of the population may increase their consumption to reach “comfortable” living norms, the richest in India (read car owners) will have to reduce their CO2 emissions like the Europeans. This will have to form the base of our sustainable transport policies for the near and long term future. Therefore, the sales of cars in the future may be accompanied by the introduction of a carbon tax that is proportional to the CO2 produced per km by vehicles. This would then justify the design and production of a mini car if it results in the overall reduction of CO2 emissions by the motor vehicle fleet in India. This can happen if there is an average downsizing of the fleet, larger vehicle owners shift to small ones and motorcycle owners do not shift to cars.


The report


            This report examines the possibility of producing a mini car that satisfies the concerns raised above. Such a car is termed the proposed small car (PSC) in this report. The design recommendations of the PSC are based on the following assumptions and associated criteria:


  1. Reduction in fleet CO2 emissions overall.
  2. Emission standards follow the strictest norms worldwide.
  3. The PSC  designed for use in mixed traffic in India would have to maximise both occupant and pedestrian safety.
  4. In 2015 the Indian per capita income may be around Rs. 85,000 (at current prices) with an an average of 2 cars per 100 persons for the country.
  5. The production of segment  A cars in India in 2015 is not likely to be greater than 1.3 million.
  6. The demand for current three-wheeler priced and sized vehicles may be greater than 900,000 annually in 2015.
  7. In 2015 the PSC would replace some of the space presently occupied by segment A cars and thre-wheelers.


Considerations for small car design


            The traditional car is called on to do too many things. This results in all current cars being grossly over-powered for normal urban and suburban use. It means that their fuel efficiency and emissions, because of unnecessary mass and engine performance, are far from ideal for the cities of Asia. Their size is a major limitation in conditions of congestion. These factors are especially relevant in the heterogeneous traffic of the megacities of India. There is an obvious need for an urban-specific vehicle with limited speed capability specifically for the needs of Indian cities.


  1. Larger used cars may provide strong competition to the PSC. Therefore, it would be useful to consider positioning the PSC in a niche that is different from the current segment A cars. The PSC should be positioned such that it takes over a proportion of the three-wheeler segment.
  2. The PSC must have as small an engine as possible to minimise fuel consumption, CO2 and pollutant emissions.
  3. PSC be designed to minimise accelerations and decelerations and allow the car to be run at optimal speeds and gears in urban areas.
  4. Limit the use of the PSC to urban roads and roads with speed limits less than 60 km/h.
  5. Maximise safety criteria both for occupants and non-occupants.


Suggested design criteria


            If the PSC is designed with an engine capacity around  600 cc, then the CO2 emissions can be expected to be as low as 80 g/km and fuel consumption around 30 km/l with optimisation of the power unit and the drive train. A designed maximum speed of 60 km/h, can bring significant benefits in terms of reducing CO2 emissions and fuel consumption. Such a car could represent a 5% reduction both in total expected fleet CO2 emissions and fuel consumption for every 10% increase in the total fleet share. If it is accepted that the proposed car does not exceed 60 km/h, and is prohibited from roads which have a higher speed limit than that, then the safety requirements become very different from the normal European mini-car which has to meet the same requirements as all other western designs.


            At present, over the life of an urban car in India, the exterior of the vehicle will injure approximately 6 times as many pedestrians and cyclists in comparison to the interior of the car injuring its occupants.  Hence great importance must be attached to the exterior geometry and the compliance of the external structures.

  1. The proposed PSC should have  a  450-600 cc engine giving 30 km/l fuel consumption and 80 g/km CO2 emissions.
  2. The NCAP tests in the US have a 35 mph flat barrier requirement whilst in Europe the Euro NCAP is a 64 km/h 40% deformable barrier impact. Given the great variety of vehicle weights and external geometries in the heterogeneous traffic of urban India, and the proposed maximum speed of 60 km/h, an appropriate regulatory requirement for the urban PSC would be a ~35 km/h rigid barrier perpendicular impact. However the permissible biomechanical limits should be more severe than currently used, to better reflect the variations to impact tolerance across the population exposed.
  3. A more effective way of specifying the requirements for lateral impact performance is to develop a number of subsystem tests using impactors to set the characteristics of the various impact zones on the inside of the car. This would follow the procedure of FMVSS 201 which uses a head impactor to test A and B pillars, side header rails and other components. Similar tests could be applied for the chest and hip impact zones.
  4. Pedestrian and bicycle impact protection in frontal crashes. Special attention to be given to windshield and surrounding area properties to minimise impact injuries to bicyclists and pedestrians.
  5. Development of simple, low cost airbags appropriate for the urban, low speed environment would appear to be appropriate and could be made mandatory eventually. It is possible that for society as whole this would be more economical as the need for expensive police enforcement measures would be reduced.
  6. Consideration of incorporating ITS possibilities including alcohol interlocks.
  7. Thee greatest possible versatility should be incorporated into the design to allow the vehicle to be a taxi, a family car, a trademan’s vehicle with modular interior packages to accommodate tools, loads of various sizes, shelving and other options to suit local conditions. OEM sponsored designs should be available for at least the following use:
  • Personal car
  • Shared car
  • Car for people with disabilities
  • Taxi
  • Plumber, electrician, TV repairman, stationary supplier, courier, postman, etc., van
  • Food delivery
  • Urban white goods delivery
  • Street food kiosk
  • Semi ambulance


Associated regulations

  1. Restriction on the numbers of taxis in cities to be removed.
  2. Introduction of parking charges proportionate to vehicle size.
  3. Road user charges in the form of CO2  tax.
  4. Banning the use of the PSC on highways with speed limits greater than 60 km/h.

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