How is it calculated? For whatever reason I have been unable to find out how much of the IC payment is pure mileage, like if it's allowed to count for their total payment to us.  

Example: I accepted a 9 dollar batch with a tip (dont hate on me, we don't get much out here) and the mileage from store to destination was 11.5 miles.  I think it was something like 11 items, so not bad. Anyway, by my calculations, that's about 7 dollars in gas payment, and 2 dollars for the actual shopping part?  I'm in an on-demand, 7 dollar minimum batch area, but on average, most orders live fairly far from the two stores we have.  

So basically is IC using the gas reimbursement as the batch payment?