Ford Focus Fuel consumption?

I have a 2012 (62) 1.6 Ti-VCT (petrol) Ford Focus and the trip computer is saying that I'm only getting 25 miles per gallon around the town etc (urban) The owner's manual says 35mpg! The car has had a full service including spark plugs.

Also when considering how much petrol is left in the tank would you use the trip computer or the pointer on the fuel gauge to judge how much petrol is left?

Snow tires on the same rims?

I have a '14 Ford Focus riding currently on the factory wheels and rims size 215/55/R16. Can I use snow on those rims?

Why is my car insurance so high?

I'm a 41 year old guy that lives in London with a EU license for over 20 years. I have been in the UK for about a year and I'm shocked that I just got enough money to buy a Audi Q7 2012 and checked my insurance that it's 150 a month! My friend pays 40GBP a month for a 20111 BMW, i don't understand? I checked my insurance on a Ford Focus and it is still at 130GBP a month, any ideas?

Can a car drive 4 hours a day and be fine?

Due to some complications I have to move to my old town, but I'm going to school in the town I'm living in currently. The distance between my town I'm moving to and the school in the one I'm currently living at is about an hour and a half to two hours depending on traffic and such. My car is a 2001 Ford Focus. I've taken pretty good care of it for the 4 years that I've had it. I just need to get a new battery. Do you think it can make the drive for a couple of months or is that too much on a car so old like that. I haven't driven it for hours at a time. I just want to know if it will be okay for the next 6 months while I'm in school.