Is it difficult for a 1.5L naturally aspirated engine to reach 120 km/h on the highway?
3 Answers
1.5L naturally aspirated engine reaching 120 km/h on the highway depends on the number of passengers in the car. Under normal circumstances, it is not difficult. The following is an introduction about engines: 1. V-type engine: Simply put, a V-type engine divides all cylinders into two groups, arranging adjacent cylinders at a certain angle (the angle γ between the centerlines of the left and right cylinder banks is less than 180°), so that the two groups of cylinders form an angled plane. Viewed from the side, the cylinders form a V-shape (usually at a 60° angle), hence the name V-type engine. 2. VR engine: The VR engine is an exclusive product of Volkswagen. In 1991, Volkswagen developed a V6 2.8L engine with a 15° angle, called the VR6, and installed it in the third-generation Golf. This engine has a compact structure, with a width close to that of an inline engine and a length not much longer than an inline 4-cylinder engine.
I often study car data, and a 1.5L naturally aspirated engine can handle highway speeds of 120 km/h, but the experience depends on the car's design. Most engines of this displacement have power outputs between 80 to 100 horsepower. Maintaining 120 km/h on flat roads only requires about 60-70% of the engine's power, so driving at this speed is generally fine. However, acceleration can be sluggish—going from 80 to 120 km/h takes several extra seconds, especially noticeable on inclines where the engine revs up to 3,000-4,000 RPM, producing a loud hum while speed increases slowly. Power loss is more pronounced when running the AC in summer or carrying a full load of passengers and luggage. For overtaking, it's best to start accelerating half a minute in advance to ensure a safe distance. Although reaching 120 km/h is possible, the high engine RPM leads to increased noise and fuel consumption, typically 2-3 liters higher than driving at a steady speed.
I've been driving a 1.5L naturally aspirated car on highways for five or six years. Honestly, reaching 120 km/h is achievable, but it requires some patience. On flat roads, gently pressing the throttle can maintain a steady 120 km/h, but it becomes challenging when encountering slopes or overtaking—flooring the accelerator sends the RPM soaring to 4000, with the engine roaring like a tractor. During summer trips with the family, the trunk packed with luggage and the AC on, uphill sections make the lack of power painfully obvious. I've learned to pick downhill stretches to build speed before passing large trucks. Fuel consumption is about 20% higher at 120 km/h cruise control compared to 100 km/h, so I usually stick to the lower speed limit. Overall, the power is adequate but don't expect thrilling acceleration—affordability and fuel efficiency are its strengths.
