OP:
Andrew_j worded it well.
If your BMW currently averages 20mpg, and a switch to regular drops the mileage by more than 1mpg, then using regular is costing you more money!
Is that what you want?
OP:
Andrew_j worded it well.
If your BMW currently averages 20mpg, and a switch to regular drops the mileage by more than 1mpg, then using regular is costing you more money!
Is that what you want?