Jenson Button hopes F1 team-mate Fernando Alonso annihilates him

After an initial run-out with Honda's 'phase four' system in first practice at the recent Russian Grand Prix, Alonso will now use the engine over the course of the entire United States Grand Prix weekend.

Button has confirmed he will be handed the power unit for next weekend's race in Mexico.

"Normally when you're team-mates you're on exactly the same [spec]," said Button.

"But I'm hoping it is a good upgrade, that he's really quick and he annihilates me all weekend - it's unusual to say that.

"When you're fighting for a world championship or at the front, everything has to be the same. I've always pushed for that.

"But in our situation it's about getting it on the car, proving it out reliability wise, and I'll have the same engine at the next race."

Alonso said the new system was an improvement, although exactly how much will only be borne out this weekend.

"From the cockpit it is difficult to feel the difference, but the data showed the improvement of the engine is as expected," said Alonso.

"This is very good news as it is a little bit of a different concept on how the engine is built, so a positive step.

"Hopefully we can use it here and exploit the performance it will give us, although obviously with the weather conditions predicted it is a little bit of a question mark on whether we can maximise the improvement.

"If we are seventh then maybe it is just the wet conditions that helped us in terms of performance.

"So it will be difficult to know exactly how big a step we will have made on the engine side, and also aerodynamically because we have new parts here that are quite interesting.

"So with the very limited running we will have on track we will have to guess a little bit and to pick up the best things.

"More important than this step is the philosophy for next year's engine that this spec has introduced, so this is a good direction to go."