Understanding petrol consumption with car power vs Hill slope
I'm no car whiz so need some help with a conundrum I have. I drive a 1.1 2009 C2, I recently moved and now live on the side of a mountain and as such our petrol consumption has exploded (I've worked out its about £3 to get up the "hill") so at least twice a day thats £6 of petrol without taking the distance of the journey into consideration. So would upgrading my vehicle to a 1.4 or 1.6 help reduce my petrol consumption (for the "hill"). We are pretty decent drivers always using the MPG gauge to try to have it as high as possible normally about 45-60 MPG until we reach this darn mountain.
Sorry if my question seems somewhat idiotic but as mentioned know barely anything about cars.
There is quite a long and steep hill just around the corner from where I live. Some years ago, I travelled up and down this hill on a daily basis for a number of years, and noticed that my two-litre petrol transit minibus gave me twice the mileage against my eleven hundred Mini. Neither vehicle had any power issues with the hill, I feel it was the increased torque of the minibus that made the difference.