Is Driving on Highways or National Roads More Fuel-Consuming?

[DeJonathan]

Driving on national roads consumes more fuel than driving on highways. Here are the specific details regarding vehicle fuel consumption: 1. Highways: Highways are generally "straighter," which means compared to national roads, the distance traveled on highways is shorter, naturally reducing the vehicle's fuel consumption. 2. National Roads: The main cost of driving on national roads lies in fuel consumption. Firstly, national roads are more congested. Once stuck in traffic, frequent braking and acceleration are unavoidable, leading to a sharp increase in fuel consumption. If encountering areas with dense traffic lights, fuel consumption will inevitably spike. National roads are usually more winding, which inadvertently increases the vehicle's travel distance, also resulting in higher fuel consumption. 3. Speed: The maximum speed limit on highways is 120 km/h. If the average speed is 100 km/h, a 100-kilometer journey takes one hour. The speed limits on national roads are completely different from highways, typically around 60-70 km/h, and in some areas with poor road conditions, the limit may be as low as 40 km/h. Due to the complex road surfaces in many parts of national roads, speeds are not very fast. If the average speed is 50 km/h, then a 100-kilometer journey would take two hours.

[ZacharyDella]

Back when I used to drive trucks for long-haul trips, I specifically measured fuel consumption. When cruising at 120 km/h on highways with the engine maintaining a steady 2000 RPM, one tank could last about 650 km. National highways were completely different – speed-limited to 80 km/h with constant braking and accelerating, especially troublesome through town sections. Once, covering the same distance took three hours, and the fuel gauge dropped much faster than on highways, working out to 2 liters more per 100 km. Automatic transmissions were particularly thirsty, as each deceleration and acceleration required gear shifts. Of course, it depends on traffic conditions – massive highway jams would drastically change the fuel economy picture.

[CeciliaRose]

With over a decade of experience in car repairs, I've noticed that modern vehicles have an optimal fuel efficiency speed range, typically between 60-90 km/h. Driving too fast on highways actually consumes more fuel due to exponentially increasing air resistance. Although national highways allow speeds within this efficient range, road conditions are more complex—slowing down at intersections, rapid acceleration for overtaking, and sudden encounters with electric scooters. Such frequent acceleration and deceleration significantly increase fuel consumption, with throttle injection rates exceeding those at constant speeds by over 30%. Therefore, unless the highway is jammed like a parking lot, maintaining a steady 80 km/h on highways is undoubtedly more fuel-efficient than the stop-and-go nature of national highways. Carbon buildup in the engine is another factor—prolonged low-speed driving accelerates carbon deposit formation.

[OMorgan]

When I first bought the car, I was also concerned about this issue and specifically installed an app on my phone to track fuel consumption. Driving on provincial highways back to my hometown over the weekend, a round trip of 200 kilometers averaged 8.2 liters per 100 km. Covering the same distance on the expressway reduced the fuel consumption to 6.9 liters. The most noticeable difference was at traffic lights: on national highways, there's roughly one red light every 5 kilometers, with each acceleration causing instantaneous fuel consumption to spike to 20 liters, and I used the brakes 87 times throughout the journey. On the expressway, I hardly needed to brake, managing speed just with the accelerator. The difference is even more pronounced for cars with larger engines—my friend's 3.0T vehicle consumes up to 12 liters on national highways but only 9 liters on expressways. Of course, winter conditions are a different story, as the heating system affects fuel consumption similarly.