Sole-Trader do i claim for mileage and report fuel costs?

HI 

I've recently gone self employed (Sole Trader). 

I'm a little confused on the following if someone could confirm I would be extremely grateful. 

Quickbooks tracks my mileage so it will deduct an amount when i complete my tax return, when I have fuel receipt I'm assuming you log this as personal and not a business expense is this correct. 

The reason why I'm assuming this is because you would be claiming fuel within the mileage travelled expense? 

Thanks in advance