"The prototype is also showing a 6-lug nut pattern on the front and rear hubs. The current Tundra has 5-lug nut hubs.
The 6-lug nut hubs would make sense for the upcoming Tundra if Toyota wants to increase the truck’s payload and towing capacities. This includes upgrading the axles, suspension, hubs, brakes, and more.
Ram did a similar thing when upgrading to the 2019 “DT” generation of the Ram 1500. Ram went from 5-lug to 6-lug hubs and increased their payload and towing capacities.
We expect the upcoming 2021 Toyota Tundra to be powered by a gas/electric hybrid powertrain. It is rumored to be a 3.5-liter turbocharged V6 engine that is mated to an electric motor/battery system.
https://www.tfltruck.com/2019/06/2021-toyota-tundra-prototype-caught-tow-testing-in-nevada-spied/