what's the opposite of this?

[dilodi83]

- I tried revving the engine and after a couple of seconds it started again, but I had to change down and get back into the slow lane and go very slowly indeed.

What's the opposite verb of "to change down"? How do you say when someone puts a vehicle into a upper gear in order to go faster?

[bhaisahab]

- I tried revving the engine and after a couple of seconds it started again, but I had to change down and get back into the slow lane and go very slowly indeed.

What's the opposite verb of "to change down"? How do you say when someone puts a vehicle into a upper gear in order to go faster?

"change up"