You should also be aware that there are several fast charging standards.
Nexus uses USB Power Delivery while most of the devices today are using the Qualcomm Quick Charge standard.
More about the difference here:
https://www.androidauthority.com/usb-power-delivery-806266/
In order to stop wondering which standard you need I recommend you purchasing one of the hybrid chargers which support both. Here is a nice example:
[https://amzn.to/2tvmazZ|63W LinkOn Car Charger]