I have an 04 Mustang, 37000 mi, kept up good - regular oil changes, new radiator, just had transmission flushed, tires inflated all of the way and rotated every 6 months but the past 3 or 4 months I've noticed that I've started getting only about 15 mpg when before it was closer to 20 or 21. What's up with that and how can I fix it?What might cause my car to get worse gas mileage suddenly?A lot of stuff, piston rings, runnign rich, bad spark plugs, excess oil burnoff, bad fuel injectors, bad fuel filter.What might cause my car to get worse gas mileage suddenly?Check your air filter and have a mechanic check timing and ignition. You may have too much carbon deposit on air flow sensor. It is also possible oxygen sensor, restricted muffler, etc. You may want to visit your local Ford dealer to check the emission system. Hopefully you are not lead foot and change your driving habit.
Good luck!What might cause my car to get worse gas mileage suddenly?Well, like others have said. Check your air filter to start with. Then look at fuel filter, spark plugs, plug wires.
Also, have you changed fuels lately? Gone from Premium to Regular? Gone from Shell to Am/Pm type fuel? There is a difference you know. The cheaper the fuel, usually the worse fuel mileage you get.What might cause my car to get worse gas mileage suddenly?Have you ever gotten a tune up?What might cause my car to get worse gas mileage suddenly?ummm....it could be a gas leackage or it could be the fuel pump that is giving too much gas and wasting it...What might cause my car to get worse gas mileage suddenly?check your air filter, if dirty replace. that wont increase it but by 1 or 2 mpg however.What might cause my car to get worse gas mileage suddenly?I have only had foreign cars, but I have had this problem. It could be your fuel filter. It can affect the gas changes. I would have someone check the filter. Some cars have 2, and some are located by the gas tank. Call you local part store and ask them where it is and if it would cause this problem.What might cause my car to get worse gas mileage suddenly?have your car serviced as a number of things cause a loss in mpg even something simple as tyre pressureWhat might cause my car to get worse gas mileage suddenly?get your fuel injection system checked as well as a full tune up(filter, hoses, plugs, etc.)What might cause my car to get worse gas mileage suddenly?Here are 7 ways to improve mpg.
1. Keep tires inflated to recommended pressure and within one pound of each other. Low tire pressure can cost 1-2 mpg.
2. Dragging brakes can decrease fuel economy. Regular brake inspections will help you keep your car rolling and stopping.
3. Synthetic lubricants have been proven to greatly reduce friction in engines and differentials. Reduced friction means better mileage and more power. Dirty oil can cost up to 0.5 mpg.
4. Keep the air filter clean, or upgrade to a high-flow filter element. Add fuel injector cleaner to the gas tank every 5,000 miles to help injectors vaporize fuel properly. A dirty air filter can cost up to 2 mpg.
5. Regular tune-ups are crucial to engine efficiency. Replace spark plug wires every 50,000 - 60,000 miles, depending on how severe your driving conditions are. A complete tune up can yield as much as 10 mpg.
6. Acceleration requires more horsepower and uses additional fuel. The harder you accelerate, the more fuel you use. Go easy on the gas.
7. Air conditioning is one of those parasitic losses that can be eliminated by simply turning off a switch. This is a big one usually woth 1-2 mpg.
Hope this helps!!What might cause my car to get worse gas mileage suddenly?I basically agree with Jim but I would suggest that in addition to your regular oil changes you get the full package offered once in a while they will check everything for you that way : )What might cause my car to get worse gas mileage suddenly?the only thing you didnt list was air filter. if your engine senses its not getting enough air it will add more gas to compensate. also if you havent changed your spark plugs and wires that could make your car get worse mileage but it would also make it lag a bit too.What might cause my car to get worse gas mileage suddenly?Many many things! One possibility is a very dirty air filter. A bad sensor. Or even wheel bearings going bad. There are so many things it could be.What might cause my car to get worse gas mileage suddenly?It could be an exhaust leak or if you got the car serviced at a garage they may have used the wrong parts.
