Eco-driving and vehicle maintenance

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Eco-driving and vehicle maintenance: the habits that cut fuel consumption, mechanical wear and environmental impact.

Coverage, Eco-driving and vehicle maintenance

Lesson objectives

Master eco-driving techniques to reduce fuel consumption and pollutant emissions Understand the impact of vehicle maintenance (tires, engine, filters) on pollution and consumption Identify good maintenance practices for driving ecologically and safely

Eco-driving: the gestures that matter

Eco-driving is an approach to driving that reduces both your fuel consumption and pollutant emissions. It is based on simple but effective gestures, applicable daily. Every decision at the wheel, engine speed, speed, acceleration, has a direct impact on the environment and your wallet.

Engine speed: the heart of eco-driving

Changing gears at the right time is the first rule of eco-driving. An engine running at too high a speed consumes enormous amounts of fuel unnecessarily.

Gear change speeds: the values expected in the exam

Engine type Recommended gear change speed Petrol 2,500 rpm Diesel 2,000 rpm These two figures are what the exam expects, to the unit. Remember them as reference points and not as a range: the question is asked in the form "at what speed is it advisable to change gear?", and the expected answer is a number.

The meaning of the rule: a diesel engine delivers its torque at low speed, so it does not need to rev high, hence 2,000 . A petrol engine needs a bit more speed to be efficient, hence 2,500 . The mnemonic: diesel, we change gear earlier . If you hesitate in the exam, diesel is always the lower of the two figures.

Dashboard with engine tachometer

Speed and consumption: slower = cheaper

The faster you drive, the more your consumption increases. At high speed, aerodynamic resistance becomes enormous. Driving with windows open makes the phenomenon worse by disrupting the vehicle's aerodynamics.

Exam trap: Many think that windows open or closed has no impact. This is false. Driving with windows open increases aerodynamic drag and therefore fuel consumption, especially at high speed.

Engine in neutral: what article 8.6 says

Article 8.6 sets two rules, and the exam tests both. 1. "It is forbidden for any driver to carry out, in neutral, repeated engine accelerations ." Revving the engine while stationary is therefore an infraction, not just an incivility. 2. "Drivers must also ensure not to leave the engine running in neutral except if necessary ." In other words: engine off as soon as the wait is prolonged without reason to keep it running.

When to turn off the engine

In front of a closed level crossing In front of a drawbridge during maneuver During a stop of indeterminate duration : delivery, waiting for a passenger, blocked traffic The nuance of article 8.6 is the word " necessary ": do not turn off the engine where you need to be able to restart immediately, at a light about to turn green, or in a line moving in fits and starts. Many recent vehicles also have a start-stop system that applies this rule automatically.

Car stopped in urban traffic jam

Vehicle maintenance: the basis of eco-driving

A poorly maintained vehicle pollutes more and consumes more. Regular maintenance is not an option, it is a legal and ecological obligation. Three elements play a crucial role: tires, engine and filters.

Tires: properly inflated, properly worn

Tire pressure must correspond exactly to the manufacturer's specifications. Incorrect pressure increases rolling resistance, which increases fuel consumption and premature wear.

Tire pressure

Amount of air inside the tire, expressed in bars. It must be checked when the tires are cold (after less than 5 km of driving), as friction with the road creates heat that changes the pressure.

Essential rules for tires

Check pressure when tires are cold (less than 5 km driven) Pressure too low → wear on tire edges + instability in turns + risk of aquaplaning Pressure too high → wear in center of tire + reduced comfort For a long trip or heavy load, increase pressure by 0.2 bar Minimum tread depth: 1.6 mm over ¾ of the tread Never drive with worn tires, the grooves cannot be recut

Frequent exam trap: Reducing tire pressure to "save fuel" is a serious mistake. This increases consumption, wears tires prematurely and reduces vehicle stability. It is forbidden.

Tire pressure check at the pump

Engine and filters: the importance of regular maintenance

A poorly tuned engine and a dirty air filter increase fuel consumption. The air filter is the « lung » of your engine, if it is clogged, the engine must work harder to get the air it needs.

Air filter

Component that purifies the air entering the engine before combustion. A dirty filter reduces engine efficiency and increases fuel consumption.

Have your car checked regularly and do not skip any maintenance. Preventive maintenance costs less than an emergency repair and protects the environment.

Load and accessories: lighten to save

Every additional kilogram increases consumption. External accessories such as a roof rack or roof box create significant aerodynamic resistance, even if they are empty.

Impact of a roof rack

A roof rack increases air resistance significantly , much more than « very slightly ». It is recommended to remove both the box and the rack (roof bars) as soon as they are no longer used to reduce fuel consumption.

Common exam mistake: Some think that a roof rack has a negligible impact. This is wrong. The increase in consumption is significant , hence the importance of removing it when not in use.

Air conditioning: a luxury that costs dearly

The use of air conditioning (A/C) increases fuel consumption. The air conditioning compressor is driven by the engine, to produce cold, the engine must provide more energy, which increases consumption.

Use air conditioning in moderation. At low speed in the city, prefer to open the windows slightly. At high speed on the motorway, air conditioning is more efficient than open windows (which increase aerodynamic drag).

Choice of fuel: a question of ecology

The road code does not classify fuels: it merely prohibits emissions of smoke and polluting gases exceeding the limits set by the technical regulations, and spilling oil or fuels on the public road (art. 81.3.1). The following classification falls under general knowledge expected in the exam.

What the exam expects on fuels

Question asked Expected answer Which fuel pollutes the least ? LPG (LPG) Which diesel is the most ecological ? Diesel with low sulfur content Which diesel is the least favorable ? Ordinary diesel, white or red Remember the hierarchy in this order: LPG at the top , then petrol, then diesel, and among diesels, the one with reduced sulfur content ahead of ordinary diesel.

Red diesel

Diesel fuel colored red, reserved for agricultural or industrial uses. Driving a car on red diesel is prohibited because taxes are not identical and it is tax fraud.

Euro standards and polluting emissions

Euro standards define the limits of polluting emissions that vehicles must not exceed. The higher the Euro standard number, the more recent the vehicle and the more it respects the environment.

Euro standard

European standard that sets the maximum limits of polluting emissions (nitrogen oxides, fine particles, etc.) for new vehicles. It appears in section V.9 of the registration certificate (registration document).

To find out the Euro standard of your car, consult your registration certificate (registration document) in section V.9. This is the only official source.

Exhaust catalyst: reducing pollution

The catalyst transforms some of the polluting gases into less harmful substances before their release. The point the exam tests: exhaust gases, when they come into contact with sunlight , transform into ozone . It is not contact with air that causes the reaction, but solar radiation , hence the ozone peaks in summer, in warm and sunny weather.

Exhaust catalyst

Catalytic system that reduces or destroys polluting gases contained in exhaust gases before their release into the atmosphere.

What the code requires of the vehicle itself

Beyond eco-driving, article 81.3.1 requires that vehicles be « designed, maintained and driven in such a way as not to endanger traffic safety or inconvenience other users ». It prohibits in particular: to abnormally spill oil or fuels on the public road; to inconvenience the public or frighten animals by noise , the noise level not exceeding the limits of the technical regulations; to produce smoke emissions exceeding these limits, except fugitive emissions at start-up or gear change; to emit polluting gases beyond the set limits. A vehicle that emits black smoke is therefore not only in poor condition: it is in breach of the law.

Key points to remember

Shift speeds : petrol 2,500 rpm , diesel 2,000 rpm , diesel always shifts earlier Article 8.6 : prohibition of repeated acceleration in neutral , and obligation not to leave the engine running in neutral except when necessary Article 81.3.1 : no oil spillage, no excessive noise, no smoke, no polluting gases beyond the limits of technical regulations Tyres : pressure checked when cold , +0.2 bar if loaded or long journey, minimum tread depth 1.6 mm ; regrooving is prohibited Open windows and roof rack : increased fuel consumption; remove roof rack when not in use Air conditioning : it consumes fuel; in town, prefer windows, on motorway, use air conditioning Fuels : LPG pollutes the least; among diesels, the one with low sulphur content is the most favourable Ozone : exhaust gases transform into ozone when in contact with sunlight Euro standard : section V.9 of the registration certificate

Congratulations!

First complete the quiz for this lesson to validate your knowledge, then practise on the exam simulator and multiple choice questions . You have completed this entire course. Congratulations, now for the practical part!

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