Maximize Mileage on Petrol Cars
With petrol prices remaining high across India, fuel efficiency has become one of the most critical aspects of car ownership. While vehicle manufacturers advertise high mileage figures based on test track conditions, the real-world fuel economy achieved by drivers in daily city traffic is often significantly lower. Fortunately, you do not need to buy a hybrid or an electric car to reduce your fuel bills. By understanding the principles of eco-driving and vehicle physics, you can learn how to maximize mileage on petrol cars and get the most out of every drop of fuel.
Fuel efficiency is determined by a combination of driving habits, traffic conditions, and vehicle maintenance. Aggressive driving, carrying unnecessary weight, and neglecting routine services can cause your car to consume up to 20% to 30% more fuel than necessary. In this comprehensive guide, we cover the best driving practices and maintenance tips to help you optimize fuel consumption, lower your carbon footprint, and save money at the pump.
Maintain Proper Tyre Pressure
Tyres are the only contact point between your vehicle and the road, and they play a massive role in determining fuel economy. To optimize mileage, you must maintain proper tyre pressure at all times. Under-inflated tyres have a larger contact patch with the road, which increases rolling resistance. This means the engine has to burn more fuel to roll the tyres forward.
According to research, running tyres that are under-inflated by just 5 PSI can decrease your fuel economy by 3% to 5%. Over-inflation is also harmful, as it reduces grip and causes uneven tyre wear. Check your tyre pressure at least once a week using a reliable gauge, and always check them in the morning when the tyres are cold. Inflate them to the recommended PSI specified by the manufacturer, which is usually listed on a sticker inside the driver's door jamb. Ensuring correct wheel alignment and balancing also reduces friction, helping to save fuel.
Avoid Hard Acceleration
Your driving style is the single most important factor influencing fuel consumption. To achieve high fuel economy, you must train yourself to avoid hard acceleration and abrupt braking. When you press the accelerator pedal aggressively, the electronic control unit (ECU) dumps a large amount of fuel into the engine cylinders to generate rapid power. Most of this fuel is wasted, as the engine cannot burn it efficiently at high RPMs.
Instead, practice smooth throttle inputs. Imagine an egg is placed under your accelerator pedal, and you must press it gently without cracking it. Accelerating gradually allows the transmission (especially automatic systems) to shift to higher gears quickly, keeping the engine operating in its most efficient RPM range (usually between 1500 and 2200 RPM for petrol cars). Similarly, anticipate traffic flow to avoid sudden braking. Rolling slowly toward a red light rather than speeding up and braking hard preserves momentum and saves significant fuel.
Drive at Consistent Speed
Maintaining a steady speed on the highway is key to achieving excellent fuel economy. You should always aim to drive at consistent speed and avoid frequent changes in pace, which force the engine to constantly work to rebuild momentum. Using cruise control on open expressways is an excellent way to maintain a steady speed and reduce fuel usage.
Additionally, understand that high speeds consume fuel rapidly. For most passenger cars, the optimal speed for maximum fuel efficiency is between 50 km/h and 80 km/h in the highest gear. Once you cross 90 km/h, aerodynamic drag (wind resistance) increases exponentially. Driving at 110 km/h consumes up to 15% to 20% more petrol compared to driving at 80 km/h, despite the journey taking slightly less time. Plan your travel time to allow for a relaxed pace on the highway to save fuel.
Reduce Excess Weight
The heavier your vehicle is, the more fuel the engine must burn to move it. To optimize efficiency, you should reduce excess weight by clearing out unnecessary items from your car. Carrying heavy luggage, sports equipment, spare toolboxes, or cargo in the boot increases the load on the suspension and engine, lowering mileage.
For every 50 kilograms of additional weight carried in the vehicle, fuel economy drops by approximately 1% to 2%. Remove roof racks, crossbars, or cargo boxes when they are not in use, as they add weight and disrupt the vehicle's aerodynamics, creating wind drag that can lower fuel efficiency by up to 10% at highway speeds. Keeping your car clean and light is a simple, cost-free way to improve mileage.
Regular Vehicle Maintenance
A neglected car will never deliver good fuel economy, regardless of how gently you drive. Ensuring regular vehicle maintenance is essential for keeping all mechanical systems running efficiently. A dirty or worn-out component forces the engine to consume more fuel to generate the same performance.
The most critical maintenance item is the engine air filter, which prevents dust and debris from entering the combustion chamber. A clogged air filter restricts airflow, altering the air-fuel mixture and causing the engine to run rich, consuming more fuel. Replace the air filter according to the service manual, or more frequently if you drive in dusty environments. Use the correct viscosity grade of engine oil recommended by the manufacturer to minimize internal friction, and replace worn-out spark plugs that can cause engine misfires and fuel wastage.
Fuel Saving Tips
Adopting small, disciplined habits in your daily driving can lead to significant cumulative savings at the pump. Follow these practical fuel saving tips:
- Turn Off Engine at Red Lights: If the waiting time at a traffic signal exceeds 30 seconds, switch off the engine. Idling consumes up to 1 to 1.5 litres of fuel per hour. Many modern cars feature auto start-stop systems that handle this automatically.
- Use the AC Smartly: Air conditioning draws power from the engine, increasing fuel consumption by 5% to 15%. At low speeds in city traffic, rolling down the windows is more efficient. However, at high highway speeds, open windows create drag; keeping them closed and running the AC is the more fuel-efficient option.
- Plan Your Routes: Combine multiple short trips into one single journey. A cold engine consumes more fuel during the first few kilometers, so running errands in one trip keeps the engine warmed up and operating efficiently.
- Use Engine Braking: In manual cars, release the accelerator and allow the engine's compression to slow the vehicle down when approaching an exit or red light, which cuts off fuel delivery completely.
Pros & Cons of Eco-Driving
Pros
- Saves up to 15% to 25% on monthly petrol expenses.
- Reduces wear and tear on tyres, brake pads, and engine components, lowering maintenance costs.
- Improves passenger comfort through smoother acceleration and deceleration.
- Lowers greenhouse gas emissions, benefiting the environment.
Cons
- Requires patience and a relaxed driving style, which can be challenging in high-stress traffic.
- May slightly increase travel time on long highway journeys due to lower top speeds.
