# Strategies for Reducing Automobile Fuel Consumption
## 4 Utilization-Related Factors
### Considerations on the Influence of Driving Modes on Energy Consumption  
_Driving modes_ (commonly identified by the more standard concept of _driving cycles_) encompass various driving characteristics and significantly impact a vehicle's fuel consumption, regardless of its technological level and maintenance practices [62]. These driving modes include factors such as the frequency and duration of stops, average speed, acceleration patterns, time spent in motion or idle, and driver behavior regarding speed and acceleration. Driving modes are influenced by variables such as road type, lanes, driver style, and time of day. Notably, different driving modes can lead to substantial variations in fuel consumption, with differences of up to 30-40% [63]. Variations in the vehicle's operation intensity lead to changes in fuel consumption due to varying instantaneous acceleration values. ICEs also exhibit operating regimes of higher energy efficiency, known as _green zones_. By predominantly driving in these efficient regimes, fuel savings can be achieved. For conventional vehicles (i.e., ICE-propelled), both _wheel work_ and efficiency are significantly low at low speeds. As the vehicle's speed increases, the wheel work experiencesa slight increase, while the efficiency increases at a higher rate, resulting in reduced total fuel consumption. At moderate speeds, the wheel work and efficiency increase roughly in proportion. Within this speed range, changes in fuel consumption occur at an approximately _constant speed_. However, at higher speeds, the efficiency either remains constant or decreases, while the wheel work increases substantially, leading to a notable increase in fuel consumption. Additionally, a challenging task is to isolate the individual effects of weight, power-to-weight ratio, and aerodynamic resistance in different types of vehicles. Generally, a vehicle with more gear changes within a specific speed range spends a higher percentage of driving time operating with high efficiency. Therefore, it is essential to recommend, during driver education, the practice of early gear shifting to a higher gear as one of the primary methods of saving fuel. When considering _driving aggressiveness_ (with respect to a reference value of 1.0 m/s2), reducing accelerations and decelerations by 10% saves more fuel than reducing road speeds by 10% [64]. Taking these considerations into account, the best driving practices for economical driving include [62] (a) driving at lower speeds allowed on roads (but staying above the posted minimum driving speed), while avoiding very low speeds in urban areas; (b) reducing the intensity of accelerations during driving; (c) minimizing short and low-speed trips whenever possible; (d) driving in the highest gear possible (for vehicles with manual transmission); (e) utilizing _cruise control_ in vehicles equipped with this feature; (f) maintaining properly calibrated tire pressure values; (g) avoiding add-ons and parts that increase aerodynamic resistance; (h) eliminating excess weight from the vehicle; and (i) using air conditioning and other accessories only when necessary. In urban driving cycles, particularly at relatively low speeds, the primary cause of fuel usage is the generalized friction of the engine, which is directly related to the number of engine revolutions during the trip. By increasing the travel speed while keeping the engine speeds relatively constant, the travel time decreases, resulting in a reduction in the total number of engine revolutions. Access to high-quality _driver education_ indirectly contributes to improved fuel economy by fostering sensible and conscious decision-making during driving. It empowers drivers to understand how vehicle handling impacts fuel consumption. Furthermore, such education enhances citizens' environmental and energy awareness, encouraging the adoption of energy-sustainable driving practices.