There's no point of just throwing out figures at the OP as it all depends on...
* What sort of roads
* How you drive
* How much it costs per litre (The tank is 55 litres BTW)
For example, I get an average of 19mpg (actual - OBC over estimates) per tank because I only do short distanced (<10miles) spirited city driving.
Under normal driving I would calculate it using the following estimates:
* 32mpg - motorway
* 26mpg - A Roads
* 20mpg - City/Town Roads
Figure out how that 800 miles splits up, find out how much petrol will be for you per litre and you'll have a better guess at what it would cost you.
I would also use this site to figure out the best place to fill up on your journey... http://www.petrolprices.com/
* What sort of roads
* How you drive
* How much it costs per litre (The tank is 55 litres BTW)
For example, I get an average of 19mpg (actual - OBC over estimates) per tank because I only do short distanced (<10miles) spirited city driving.
Under normal driving I would calculate it using the following estimates:
* 32mpg - motorway
* 26mpg - A Roads
* 20mpg - City/Town Roads
Figure out how that 800 miles splits up, find out how much petrol will be for you per litre and you'll have a better guess at what it would cost you.
I would also use this site to figure out the best place to fill up on your journey... http://www.petrolprices.com/