Model: ZF 8HP50
Model: BMW 3 Series
Model year: 2020.
Driving experience
This gearbox cooperates with the power output of the engine very smoothly, but at low speed, the gearbox is eager to upshift, and there will be a slight setback if driving on a congested road. However, there is no problem when the vehicle is driving normally, and you can also entertain yourself with simulated sound.
Technical characteristics of gearbox
Structurally, ZF's 8AT consists of four planetary gear mechanisms and five shift clutches. The engine is connected with the torque converter, which has a quick locking function and can reduce the power loss caused by the torque converter.
The maximum transmission ratio of each gear in the gearbox is 4.696, the minimum transmission ratio is 0.667, and the transmission ratios of two adjacent gears are 1.25- 1.5, and the difference is not too big, which can realize very smooth gear shifting.
At present, the latest BMW 5 Series adopts the third generation 8HP products, which realizes the electromechanical integration system, optimizes the torsional shock absorber, further improves the driving comfort and reduces the fuel consumption by 2.5%.
Gearbox problem
In terms of mechanical properties, ZF's 8AT is not a big problem, but many car owners report that the gearbox leaks oil seriously. Moreover, this oil leakage phenomenon exists in both imported and domestic models, and has little to do with the localization of 8PH series gearboxes.