Why does the car consume more in winter and how to reduce it?

The increase in fuel consumption during winter is a reality faced by most drivers and is the result of a combination of several factors. In short, the engine needs more effort to operate optimally at low temperatures, and the road conditions specific to the cold season also contribute to this situation. A full tank of 50 liters of gasoline, which costs an average of 432 de lei today, can be depleted faster due to these reasons.

Among the most important reasons are cold starts, where the engine operates in a richer fuel mixture until it reaches its optimal operating temperature, as well as the increased viscosity of the engine oil. Also, winter tires, although essential for safety, generate greater rolling resistance. Last but not least, the frequent use of heating and defrosting systems puts additional strain on the alternator and, implicitly, the engine.

A cold start is one of the most significant factors leading to increased fuel consumption in winter. When the engine is cold, the car's computer injects a larger quantity of fuel to ensure a rapid and stable ignition and to allow it to reach its optimal operating temperature faster. This happens because both combustion efficiency and catalytic converter operation depend on reaching certain temperatures. Thus, for one liter of diesel, which today has an average price of 9,43 lei, up to 15-20% more can be consumed in the first minutes of operation, compared to an already warmed-up engine.

The impact is even more noticeable in the case of short trips, where the engine does not have enough time to warm up. If you travel short distances, the engine will constantly be in the "warming-up" phase, consuming more fuel. For example, a trip of just a few kilometers, repeated multiple times a day, will lead to significantly higher consumption than a long trip, where the engine quickly reaches its optimal temperature and maintains its efficiency. Therefore, even usual commutes, such as those to the supermarket or school, can drain a full tank of petrol worth 432 de lei faster.

Winter tires are mandatory and vital for road safety in the cold season, offering superior grip on snow, ice, and wet roads. However, they contribute to an increase in fuel consumption. The main reason is their softer composition and tread pattern, which has a design with larger blocks and deeper grooves. These characteristics, essential for traction, actually increase rolling resistance. Essentially, the engine has to work harder to turn the wheels and propel the car.

Also, tire pressure decreases with falling outside temperatures. A tire with pressure below the optimal level has a larger contact patch with the road, which again increases rolling resistance and, implicitly, consumption. A difference of just 0,2 bari can significantly influence efficiency. Therefore, even if a liter of petrol 95 costs on average 8,65 lei, a set of correctly inflated winter tires can help you save part of this cost, transforming a mandatory expense into a less costly effort.

The viscosity of engine oil plays an important role in fuel efficiency, especially in winter. At low temperatures, the oil becomes thicker and less fluid. This means that the oil pump has to exert considerably more effort to circulate it through the engine, and the internal engine parts encounter greater friction resistance. The extra effort required to overcome this resistance directly translates into higher fuel consumption.

It's not just the engine oil that's affected. Transmission fluid, power steering fluid, and even differential fluid also become more viscous in the cold. All these components require more energy to function, and that energy comes from burning fuel. That's why a car starting at -10 degrees Celsius will consume significantly more in the first few minutes compared to one starting at +20 degrees Celsius. Choosing an engine oil with a viscosity grade suitable for the cold season, according to the manufacturer's recommendations, can mitigate this effect, contributing to savings on a full tank of diesel of 472 de lei, for example.

Intensive use of electrical accessories in the cold season also contributes to increased fuel consumption. In modern cars, seat heating systems, windshield and rear window defogging, powerful fans for warm air, windshield wipers, and permanently lit headlights (or DRLs) are all electrically powered. The alternator, which generates the necessary electricity, is driven by the engine. The more electrical accessories are switched on, the more effort the alternator exerts, in turn requiring more power from the engine.

This additional demand translates into higher fuel consumption. Even an air conditioning system set to maximum heat, with fans at high speed, can increase consumption by a good few percentage points. Although the impact of each accessory individually may seem minor, their cumulative effect can add an extra expense to each full tank. For example, for a 50-liter tank of gasoline costing 432 de lei, a 5-10% increase in consumption can mean an extra cost of 20-40 de lei per tank, just due to electrical demand.

Although increased fuel consumption in winter is partially unavoidable, there are effective methods drivers can use to reduce the impact on their budget. Adopting a preventive and smooth driving style is essential: sudden accelerations and aggressive braking, typical of congested traffic, can significantly increase consumption. It is preferable to accelerate gradually and maintain a constant speed, especially since in winter, reduced grip inherently requires a more cautious approach. This, combined with intelligent route planning to avoid traffic jams, can lead to considerable savings.

Regular tire pressure checks are another crucial step. As mentioned, underinflated tires increase rolling resistance and, implicitly, consumption. A check at least monthly, at a fuel station (PretCarburant.ro monitors 1390 stations, where you can also check the pressure), can save you money. Last but not least, a well-maintained car, with air filters and spark plugs in good condition, will operate more efficiently. Although fuel prices vary between stations by up to 0,66 lei/L for gasoline, optimizing your driving style and car maintenance can bring you even greater savings, independently of the pump price.

Using autogas (LPG) can be an excellent solution to significantly reduce fuel costs throughout the year, including winter. The price difference is substantial: a liter of gasoline 95 costs an average of 8,65 lei, while autogas (LPG) has an average price of only 4,56 lei/L. This difference of 4,09 lei/L in favor of LPG represents a considerable long-term saving, especially for drivers who cover long distances.

However, it is important to note that, in low-temperature conditions, most LPG systems start the engine on gasoline and switch to LPG only after the engine reaches a certain temperature (usually between 30-40 degrees Celsius). This means that, especially on short journeys, part of the journey will be covered on gasoline, partially offsetting the economic advantage of LPG. Nevertheless, for longer journeys, where the engine heats up quickly, the saving remains significant. Even if a 50L tank of gasoline costs 432 lei, the predominant use of LPG can considerably reduce the monthly fuel budget.