Is the 48V Mild Hybrid System Fuel-Efficient?

[ColinLee]

48V mild hybrid system is fuel-efficient. Here are the relevant introductions about the 48V mild hybrid system: 1. A brief introduction to the 48V mild hybrid system: The 48V system replaces the 12V energy storage battery in traditional fuel vehicles with a 48V energy storage battery or directly adds a 48V battery, equipped with a 48V integrated starter generator and a bidirectional converter. The power of the 48V integrated starter generator is used to compensate for the low-speed torque of the internal combustion engine, achieving the goal of fuel efficiency. 2. Advantages of the 48V mild hybrid system: It enables the car to power higher-power onboard systems and drive higher-power start-stop motors. It can more easily drive the engine crankshaft to wake up the engine, reducing system operation delays and jerky sensations, and also allows for more functions.

[LaJune]

The 48V mild hybrid system does save fuel, especially in traffic jams where its advantages are most pronounced. In traditional cars, the engine has to shut down and restart at every red light, which is particularly fuel-consuming. Mild hybrid vehicles rely on that small electric motor for smooth start-stop operations, not only saving idle fuel consumption but also storing the energy wasted during braking into the battery. When the air conditioning is on, the motor can also assist in power supply, so the engine doesn't have to operate at high load all the time. I've actually driven several 48V mild hybrid cars, and the combined fuel consumption in the city can drop by 10% to 15%, though the difference isn't as significant on highways. However, since this system isn't very costly, it's now becoming common even in cars priced around a hundred thousand yuan.

[DiGrace]

After switching to a mild hybrid SUV last year, the most noticeable benefits are the quiet and fuel-efficient starts at traffic lights. The electric motor can independently power the vehicle for a slow crawl of over ten seconds, delaying engine activation. The battery's ability to recover braking energy is particularly useful, especially on downhill sections. The manufacturer claims an 8%-12% comprehensive fuel saving, and based on my own fuel consumption records, it saves about 0.8 liters per 100 kilometers in urban driving. However, maintenance costs should be considered—replacing that small lithium battery can cost several thousand, though it should last seven to eight years under normal driving conditions. The fuel-saving effect is most pronounced in areas with frequent auto start-stop, while it's less noticeable in suburban driving.

[LeAubree]

The 48V mild hybrid is not a revolutionary technology, but more like an energy-saving patch for traditional gasoline cars. At its core, a BSG motor replaces the generator, with a power output of around 10 kilowatts. This motor can perform three main functions: giving the car a push during startup, acting as a generator to recover energy during braking, and powering the air conditioning compressor when the car is stationary. Particularly in summer when waiting at traffic lights, traditional cars must keep the engine running to power the air conditioning, whereas the mild hybrid system can use the battery for this purpose. Experimental data shows that fuel savings of about 12% can be achieved in urban driving conditions, but if you mostly drive on highways, the savings may only be 3%-5%. After all, the base engine displacement remains unchanged, and at constant speeds, the gasoline engine still does the heavy lifting.