Why does BYD DM-i not have a transmission?
2 Answers
BYD's DM-i technology is an improvement on Honda's i-MMD technology as pure electric vehicle technology continues to mature, relying more on batteries and electric motors, thus eliminating the transmission. Here is the relevant introduction from BYD: 1. It can meet the demand: If BYD needs rapid acceleration at high speeds, the electric motor will cooperate to drive, which can also meet the demand, but the efficiency of the motor will decrease at high speeds, making it difficult for DM-i technology to accelerate again at high speeds. 2. Economy: BYD is more suitable for urban use, and can also handle high-speed long-distance driving when necessary, but it does not meet the demand for aggressive driving. If long-term high-power driving conditions are required, such as prolonged ultra-high-speed driving, DM-i technology cannot handle it. 3. Adaptation to normal driving: Basically, DM-i technology vehicles will enter the engine direct drive state only when the speed is above 80. According to the standards designed for highways and roads, there cannot be large slopes at speeds above 80 km/h, and the speed cannot be maintained above 80 km/h when climbing large slopes, so this technology can adapt to normal driving needs without any problems.
I noticed that BYD's DMi system doesn't have a transmission, mainly because its design is quite ingenious. The characteristic of electric motors is that they can directly output high torque at various speeds without relying on multi-gear shifting. The DMi uses an electric hybrid system, transmitting power through a fixed reduction gear instead of a complex transmission. This simplifies the structure, makes the car lighter, and provides smoother acceleration. I've discussed with some car enthusiasts that traditional transmissions are prone to failure, and the DMi eliminates this part, significantly reducing maintenance costs. Its EHS unit intelligently controls power output, saving fuel while improving reliability. Overall, this pure electric drive method represents the future trend of hybrids, reducing mechanical losses and offering an excellent driving experience.
