Car question

[tw]

Originally Posted by BigV

tw, how does recording the mileage the car gets per tank fix a rough idle?

A solution only exists when the problem is first defined. Some of those suggestions cause significant mileage decreases. Others (ie oxygen sensor) do not. Just one of many reasons why mileage numbers are important for solutions. Better help means first providing better information. Only relevant fact is roughness in idle. Nothing else identifies meat necessary for a solution.