Huawei's best SuperCharge wired power adapter can charge a compatible device at up to 40 watts (W). However, a leak points to a new generation of these accessories that is capable of 66W. The OEM has reportedly had it approved for use by the regulator 3C, which may make it available for the Mate 40 series.
https://www.notebookcheck.net/Huawei-may-have-66W-power-bricks-for-the-Mate-40-series.480266.0.html