Apparently every A8 model is now a mild hybrid. V6 TDI, V6 TFSI and W12 TFSI available from launch, with V8 TDI and V8 TFSI to come.
https://www.motor1.com/news/166972/2018-audi-a8-reveal
(https://icdn-3.motor1.com/images/mgl/6vOX7/s3/2018-audi-a8.jpg)
(https://icdn-1.motor1.com/images/mgl/kZyL4/s3/2018-audi-a8.jpg)
(https://icdn-5.motor1.com/images/mgl/7XrVo/s3/2018-audi-a8.jpg)
(https://icdn-5.motor1.com/images/mgl/OPAqM/s3/2018-audi-a8.jpg)
(https://icdn-9.motor1.com/images/mgl/8qrVo/s3/2018-audi-a8.jpg)
(https://icdn-4.motor1.com/images/mgl/or977/s3/2018-audi-a8.jpg)