i found this on a web site where they recorded m.pg for the life of the car
http://www.web-cars.com/math/miata_mileage.html
In the logs we recorded anything that might affect the mileage. All tune-ups were noted for example. A couple of times the spark plug wires pooped out. At 166,233 miles a Jackson Racing Cold Air Induction kit was installed, at which time the timing was reset to 10° and we started to use 92 octane fuel. Strangely enough, these items did not make a noticeable difference.
One item that showed up big time on the results was the catalytic convertor going south. It went at about 205,000 miles, and was the original catalytic, so it's not like we have a complaint! There was plenty of warning in the form of a distinct rattle. On our annual pilgrimage to Monterey CA for the "Car Weekend" (as it has come to be known), it became a problem, as power was significantly down and the engine was running hot. An emergency repair was performed on Sunday at Midas Muffler of Seaside CA. Before that the mileage had been dropping: 28.401 MPG, 26.705 MPG, 26.459 MPG, and then 22.453 MPG. After the repairs, it shot up to 27.005 MPG.
http://www.web-cars.com/math/miata_mileage.html
In the logs we recorded anything that might affect the mileage. All tune-ups were noted for example. A couple of times the spark plug wires pooped out. At 166,233 miles a Jackson Racing Cold Air Induction kit was installed, at which time the timing was reset to 10° and we started to use 92 octane fuel. Strangely enough, these items did not make a noticeable difference.
One item that showed up big time on the results was the catalytic convertor going south. It went at about 205,000 miles, and was the original catalytic, so it's not like we have a complaint! There was plenty of warning in the form of a distinct rattle. On our annual pilgrimage to Monterey CA for the "Car Weekend" (as it has come to be known), it became a problem, as power was significantly down and the engine was running hot. An emergency repair was performed on Sunday at Midas Muffler of Seaside CA. Before that the mileage had been dropping: 28.401 MPG, 26.705 MPG, 26.459 MPG, and then 22.453 MPG. After the repairs, it shot up to 27.005 MPG.
