Abstract
As fuel prices continue to rise and air pollution worsens across many Indian cities, more people are beginning to ask a simple question: Can old petrol cars be transformed into affordable electric vehicles instead of being discarded?
A recent engineering study explored this exact idea by converting a Maruti 800 — one of India’s most iconic small cars — into a fully electric vehicle (EV). The paper examined the complete process of replacing the original petrol engine with an electric drivetrain, including motor selection, battery sizing, simulation testing, and energy-efficiency analysis.
What makes the study particularly interesting is that it does not focus on luxury EV technology. Instead, it investigates whether ordinary middle-class vehicles can realistically become low-cost electric cars for daily city transportation. Through engineering calculations and MATLAB/Simscape simulation, the researchers demonstrated that the converted Maruti 800 could achieve approximately 10 kWh/100 km efficiency while maintaining stable voltage, smooth acceleration, and regenerative braking capability.
The study provides a practical example of how EV retrofitting may become an important solution for sustainable transportation in developing countries such as India.
1. Introduction
Imagine walking through the crowded streets of Delhi, Mumbai, or Hyderabad during rush hour. Thousands of motorcycles, buses, and cars fill the roads, while the air becomes heavier with pollution every year. At the same time, fuel prices continue climbing, making transportation increasingly expensive for ordinary families.
For many people, electric vehicles seem like the perfect solution. They produce no tailpipe emissions, reduce fuel dependency, and promise lower operating costs. However, there is one major problem: brand-new EVs are still expensive for a large portion of India’s population.
This is why a growing number of engineers and researchers are turning their attention toward EV retrofitting — the process of converting existing petrol or diesel vehicles into electric vehicles instead of buying new ones.
One recent paper focused on a very familiar car in India: the Maruti 800. Once considered the “people’s car” of India, millions of Maruti 800s were sold over several decades because of their affordability, simplicity, and lightweight design. Even today, many of these vehicles remain operational.
The researchers behind the paper believed that the Maruti 800 could become an ideal candidate for low-cost EV conversion. Instead of sending old vehicles to scrap yards, why not reuse their chassis and transform them into clean urban electric cars?
The study aimed to answer four major questions:
- How much power does a converted Maruti 800 actually need?
- What type of electric motor and battery are suitable?
- Can simulation software validate the design before physical implementation?
- Is retrofitting economically practical compared to buying a new EV?
2. Literature Review
The paper began by examining how EV retrofitting has grown globally in recent years. In many developed countries, vehicle conversion started mainly as a hobby among classic car enthusiasts. However, in developing countries such as India, the motivation is very different. Here, retrofitting is viewed as a practical and affordable solution for reducing emissions while extending the life of existing vehicles.
The researchers referred to a report from the Global Green Growth Institute (GGGI), which suggested that retrofitting old vehicles into EVs can significantly reduce lifecycle carbon emissions compared to continuing to operate petrol-powered cars.
One particularly influential example came from a 2020 Team-BHP forum post documenting a successful Maruti 800 EV conversion. That project used a BLDC motor and LiFePO4 battery pack and reportedly achieved a driving range of approximately 120 km with a top speed of 80–85 km/h. According to the paper, this example proved that lightweight Indian cars could function effectively as electric vehicles without requiring factory-level manufacturing facilities.
The authors also discussed the emergence of commercial retrofit businesses in India. Companies such as Mechatronic Trading now offer EV conversion kits for small cars including the Maruti 800 and Tata Nano. This indicates that EV retrofitting is slowly transitioning from experimental projects into a potential commercial industry.
From a technical perspective, previous studies highlighted several important engineering considerations:
- PMSM motors offer high efficiency and strong torque performance for compact vehicles.
- Retaining parts of the existing drivetrain can simplify conversion.
- Battery placement and thermal management remain critical safety concerns.
- Regulatory approval processes in India are still evolving.
Overall, the literature strongly supported the idea that retrofitting small vehicles into EVs is both technically feasible and economically promising.
3. Methodology
The most interesting part of the paper was how the researchers carefully planned the actual conversion process.
Choosing the Maruti 800
The Maruti 800 was selected mainly because of its lightweight structure. With a kerb weight of around 670 kg, the car requires less energy to move compared to larger vehicles. Its simple mechanical layout also makes modification easier.
The researchers removed the following petrol-engine components:
- 3-cylinder petrol engine
- Fuel tank
- Exhaust system
- Radiator and cooling system
- Alternator and related wiring
These components were replaced with an electric drivetrain consisting of:
- 10 kW PMSM electric motor
- 48 V / 200 Ah LiFePO4 battery pack
- Motor controller
- Battery Management System (BMS)
- DC-DC converter
- Regenerative braking system
Engineering Calculations
Before selecting components, the authors performed theoretical force and power calculations. They calculated rolling resistance, aerodynamic drag, and gradient forces to estimate how much power the converted vehicle would require during normal city driving.
Their calculations showed that approximately 5 kW of continuous electrical power would be needed at 60 km/h. However, to provide additional torque for acceleration and hill climbing, they selected a 10 kW PMSM motor.
The battery pack was sized at 10.24 kWh, which provided enough reserve capacity beyond the minimum calculated requirement.
Simulation Using MATLAB/Simscape
Rather than immediately building the car physically, the researchers first tested their design using MATLAB/Simscape simulation software.
The virtual EV model included:
- High-voltage battery system
- Motor drive unit
- Speed controller
- Gear reduction system
- Regenerative braking system
The simulated driving cycle represented a realistic urban driving situation where the car accelerated to 60 km/h, cruised steadily, and then decelerated smoothly.
4. Results and Discussion
The simulation results were surprisingly encouraging.
Battery Performance
During acceleration, battery current briefly reached around 300 A, which is expected when moving a vehicle from a stationary position. Despite this high demand, the battery voltage remained relatively stable between 46.5–48.5 V.
The researchers also observed successful regenerative braking. During deceleration, the motor temporarily acted as a generator and returned energy back into the battery pack.
Energy efficiency stabilized at approximately:
10 kWh/100 km
This result was relatively close to the theoretical estimate of 8.62 kWh/100 km, suggesting that the engineering calculations were accurate.
Motor and Vehicle Performance
The simulation demonstrated that the converted Maruti 800 could comfortably achieve urban driving speeds.
- Peak motor torque reached around 40 Nm.
- Motor speed operated within the intended RPM range.
- Vehicle acceleration remained smooth and stable.
The researchers concluded that the 10 kW PMSM motor was appropriately sized for lightweight city transportation.
Limitations Discussed in the Paper
The authors also acknowledged several limitations.
First, the simulation did not fully model thermal behavior, meaning real-world battery heating could differ from simulation predictions.
Second, actual Indian road conditions — including traffic congestion, potholes, and uneven roads — were not fully represented in the virtual drive cycle.
Third, the study focused primarily on technical feasibility rather than government approval or large-scale commercialization.
5. Conclusion
The paper ultimately presented a compelling argument for EV retrofitting in India. By converting a lightweight and widely available vehicle such as the Maruti 800 into an electric vehicle, the researchers demonstrated that affordable urban EV transportation may be achievable without purchasing expensive new cars.
Their simulation results showed that the converted vehicle could achieve acceptable efficiency, reliable battery performance, and functional regenerative braking while remaining significantly cheaper than most new EVs currently available in India.
More importantly, the study highlighted a broader idea: sustainability does not always require building something entirely new. Sometimes, transforming existing technology can be equally powerful.
As EV adoption continues growing worldwide, retrofitting old vehicles may become an important bridge between traditional transportation and a cleaner electric future — especially in developing countries where affordability remains one of the biggest barriers to change.
References
- A discussion thread published on the Team-BHP automotive forum documented the successful conversion of a Maruti 800 into an electric vehicle, including technical modifications, battery configuration, and driving performance observations. See: https://www.team-bhp.com/forum/electric-cars/223306-ev-conversion-my-maruti-800-a.html?
- Mechatronic Trading provided commercial information regarding EV conversion kits designed for small Indian vehicles such as the Maruti 800 and Tata Nano, highlighting the growing retrofit ecosystem in India. See: https://mechatronictrading.com/product/electric-car-conversion-kit-india-maruti-800?
- Jang, C. S., Coelho, I. C. B., and An, C. (2023). Electric Vehicle Retrofitting: A Guide to Policy-Making. Global Green Growth Institute (GGGI), Technical Report No. 29, Seoul. The report discusses policy frameworks and environmental impacts associated with vehicle retrofitting initiatives.
- Eydgahi, A., and Long, E. L. (2011). Converting an Internal Combustion Engine Vehicle to an Electric Vehicle. Proceedings of the 2011 ASEE Annual Conference & Exposition, Vancouver, Canada. DOI: 10.18260/1-2–17664. The paper explains engineering considerations involved in ICE-to-EV conversions.
- Almeida, F., and colleagues (2021). Modelling and Simulation of Electric Vehicles Using Simulink and Simscape. IEEE Conference Publication. DOI: 10.1109/document9625192. This study explores EV simulation techniques using MATLAB Simulink and Simscape platforms.
- Hoeft, F. (2021). Internal Combustion Engine to Electric Vehicle Retrofitting. Published in Renewable and Sustainable Energy Reviews by Elsevier. The publication examines sustainability and environmental benefits of EV retrofitting.
- River Publishers (2023). A Study on Conversion of ICE Vehicle to EV. Published as part of the River Publishers Series in Transport Technology. The publication reviews technical methods and challenges involved in EV conversion projects.
- Shrivastava, K., and Bansal, R. (2020). Conversion of Conventional Vehicle into an Electric Vehicle. Advances and Applications in Mathematical Sciences, Vol. 20, No. 1. The study discusses mathematical and engineering approaches for vehicle electrification.
