Audi Q4 e-tron brakes & recuperation
The Q4 e-tron has advanced brakes that use brake by wire technology to blend between regenerative and physical braking.
Audi Q4 e-tron regenerative brakes
When using regenerative brakes, the rear and front motor (on Q4 45/50) are used as generators to convert the kinetic energy to electric energy and put it back in the battery.
When the Audi Q4 e-tron moves in gear D (drive), and the driver takes their foot off the accelerator pedal, the drive switches to coasting mode.
Both electric motors – or the rear motor in the rear-wheel-drive models – run freely and primarily without energy consumption.
Coasting takes priority because it is the most efficient.
If the driver prefers recuperation, however, they have various options for this. For example, in gear B (brake), the drive almost always recuperates when coasting but not when the car is at a standstill.
The regen braking limit is at 0.15 g of deceleration. If “dynamic” mode is set in the optional Audi drive select dynamic handling system (standard in the Sportback), recuperation also occurs in gear D.
The optional shift paddles on the steering wheel enable the driver to select three different manual recuperation levels in position D – 0.06 g, 0.10 g, and 0.15 g. The car will remember the regen level in dynamic mode after using the throttle. In other drive select modes, the regen level will reset to 0 after using the throttle.
The driver can also choose automatic recuperation in the MMI system. When the car enters a zone that enforces a lower speed or when it comes up behind a slower car in front, the drive management system attempts to reduce speed by coasting.
If the distance available is too short, it switches to coasting recuperation up to 0.10 g.
The predictive efficiency assist system must be activated in the Audi Q4 e-tron for automatic recuperation to cut in. When braking, the PSM motor at the rear alone performs the deceleration in most everyday driving situations.
The quattro models, Audi Q4 e-tron 45/50, can brake electrically at up to almost 0.3 g, equivalent to a recuperation performance of up to 145 kW. The electric brake booster only activates the hydraulic wheel brakes if more significant deceleration is required. The transition between regeneration and physical brakes is almost unnoticeable. The recuperation remains active almost until the vehicle is at a standstill.
The quattro models prioritize recuperation on the rear axle but also use the front electric motor in a few situations.
Audi Q4 e-tron physical brakes
Audi uses disk brakes for the front wheels.
On the rear wheels it uses drum brakes.