Since nothing is cached now, you can probalby update all the fuel prices using a sql query, something like
update phpvms_pireps set fuelunitcost='1.10';
update phpvms_pireps set fuelprice = fuelunitcost * fuelused;
That'll change the fuel price in bulk, and then the complete price.
That financedata table isn't used anymore, so I wouldn't worry about it