I got about 30mpg when I brought home the car two years ago but within the last 6 months or so the mileage has gotten worse. The worse mileage I saw was 22mpg I then changed the air filter and oil/oil filter and I recorded 24mpg. Please make suggestions on how I can improve my gas mileage. Again the car has a 2.0L and 50,000 miles. Thank you!Any suggestions as to why I'm only getting 22-24mpg on a 04 Mazda 3i w/50k miles?Try a couple tanks of permeium gasoline and fuel injection cleaner. Are you using the same brand of tire? or just bought the cheep ones or wider ones rolling resistance might hurt mileage? Air pressures clean paint %26amp; wax job yes that helps too. It would not hurt to look at the spark plugs just one because the change interval is 60,000 I think for platinum tip plug. If the electrode is rounded and gap is .090%26quot; or more replace the plugs with NGK or NIPPON DENSO or Mazda brand No other plugs will work right.Any suggestions as to why I'm only getting 22-24mpg on a 04 Mazda 3i w/50k miles?might need a new fuel filter,it may be clogged. talk to the mazda service dept.Any suggestions as to why I'm only getting 22-24mpg on a 04 Mazda 3i w/50k miles?spark plugs-spark plug wire-coil and make sure your fuel system is up to notch. No dirty injectors or bad pump and regulator.Any suggestions as to why I'm only getting 22-24mpg on a 04 Mazda 3i w/50k miles?as a car gets older part wear, causing decrease in mileage, air pressure, driving style and maintain it up to specs.Any suggestions as to why I'm only getting 22-24mpg on a 04 Mazda 3i w/50k miles?check your wheel balance and alignment. I had a similar problem with my 03 corolla (mine gave me 24 mpg) then i found out that my wheels are out of balance (you are not gonna feel much difference when your wheels are not balanced unlike the alignment issue) and also do tune-up to your car. Tune-up costs you abt 60$-80$ and balance and allignment costs you about 80$. After i got allignment, wheel balance and tune-up my MPG drastically increased from 24 to 35.Any suggestions as to why I'm only getting 22-24mpg on a 04 Mazda 3i w/50k miles?The main culprit, as in any car that sees a bad drop in gas mileage is the oxygen sensor, which on your car there's 2. There's one before the catalytic converter, one after. The first one should be located on the exhaust manifold or near it, the next should be right after the catalytic converter.
To replace both (and you need to do both) is about $200 but is an easy job. It's pretty much like changing spark plugs...piece of cake.
Do it soon or you will end up ruining your catalytic converter, which is like $500 or $600 each.
