Why is my car losing gas mileage?

Why is my car losing gas mileage?

A bad fuel injector or dirty/old fuel filter can drastically affect the flow of fuel into the engine. A fuel system problem is one of the most common causes of poor gas mileage. The more you run your A/C, the lower gas mileage you will get.

What causes a sudden drop in gas mileage?

Such a drastic drop in mileage is often associated with a bad 02 sensor. I’ve had them go bad and cause a 25-35% drop in fuel efficiency. Did you have anything done to the car just before the mileage dropped? A drop like this has to have an assignable cause, and it often traces back to a maintenance that was just performed.

What does it mean when Your MPG drops 20%?

BTW, there is a code if the ECT (engine coolant temp) does not come up withing a certain time frame. You could also have a fuel leak. My 2010 FIT dropped 20% immediately upon moving to a much colder climate. I checked tire pressure and changed air filter, changed gas stations. Still off by 20% ( 10 miles per gallon).

How can I tell if my gas mileage is too low?

Periodically checking your tires with an inexpensive pressure gauge is a good way to catch this. Just be sure to use your car manufacturer’s recommended pressure levels stamped onto the driver’s side doorplate and not the “maximum pressure” numbers shown on the tire itself.

How to calculate gas mileage per 100 kilometers?

When you calculate liters per 100 kilometers (l/100km) you are calculating volume per 100 units of distance, or fuel consumption rate. Fill up your tank with fuel before you start a long trip or the block of time you want to track. Record the trip starting odometer reading at the time you fill up. At the end of your trip, fill up your tank again.

When to worry about your car’s gas mileage?

When the system is working as designed, and under certain conditions, maximum fuel efficiency will be achieved. Numerous factors can have an affect on fuel efficiency so it is usually a constantly changing number but a serious and sudden drop in miles per gallon is cause for concern and the vehicle should be inspected.

Such a drastic drop in mileage is often associated with a bad 02 sensor. I’ve had them go bad and cause a 25-35% drop in fuel efficiency. Did you have anything done to the car just before the mileage dropped? A drop like this has to have an assignable cause, and it often traces back to a maintenance that was just performed.

BTW, there is a code if the ECT (engine coolant temp) does not come up withing a certain time frame. You could also have a fuel leak. My 2010 FIT dropped 20% immediately upon moving to a much colder climate. I checked tire pressure and changed air filter, changed gas stations. Still off by 20% ( 10 miles per gallon).

When you calculate liters per 100 kilometers (l/100km) you are calculating volume per 100 units of distance, or fuel consumption rate. Fill up your tank with fuel before you start a long trip or the block of time you want to track. Record the trip starting odometer reading at the time you fill up. At the end of your trip, fill up your tank again.