How accurate are MPG gauges?

As gas prices rise, drivers are paying closer attention to the fuel economy gauges that are found in most late-model cars as part of the trip computer. The only problem is that the gauges are inaccurate. In fact, Edmunds testing reveals that one such gauge claimed fuel economy 19 percent higher than the actual result.

How do I get an accurate MPG?


  1. Get the miles traveled from the trip odometer, or subtract the original odometer reading from the new one.
  2. Divide the miles traveled by the amount of gallons it took to refill the tank. The result will be your car’s average miles per gallon yield for that driving period.

Why is my Ford Focus getting bad gas mileage?

A bad fuel pump can lead to a rough running engine because it is not getting enough fuel. This will lead to a decline in gas mileage. If this issue is not addressed it will lead to a rough, idle, sputtering and stalling. Clogged Fuel Filter: A clogged fuel filter will also cause problems with gas mileage.

Are fuel ranges accurate?

Firstly, the fuel range display is pretty accurate as a rule, but it uses calculations based on your “real time” MPG, and driving style. So depending on how you’re driving and the type of driving you’re doing, you’ll see the fuel range number change drastically at times.

Can I reset my MPG?

You can also calculate fuel economy by resetting your vehicle’s trip odometer, filling the tank to capacity, and writing down the mileage and gallons the next time you refuel. Then, simply divide the two numbers to arrive at your vehicle’s fuel economy.

Why is my MPG going up and down?

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.

Why is my car using more fuel than normal?

If your fuel injectors are faulty and insufficient fuel is being injected into the engine, your car won’t run efficiently. A less efficient engine means increased fuel consumption. Air filters and oxygen sensors ensure that the ratio of air and fuel going into the engine is correct for optimum performance.

How many miles do I really have until empty?

There’s no hard and fast measurement — each automaker turns the light on with different amounts of gas left in the tank — but a general rule of thumb is between 30 and 50 miles.

What’s the average MPG of a 2014 Ford Focus?

2014 Ford Focus MPG Based on data from 711 vehicles, 64,417 fuel-ups and 17,602,362 miles of driving, the 2014 Ford Focus gets a combined Avg MPG of 28.68 with a 0.05 MPG margin of error. Below you can see a distribution of the fuel-ups with 876 outliers (1.34%) removed. Following shows the average MPG of each of the 711 vehicles in the system.

Why does my Ford Focus have an inaccurate fuel gauge?

The vehicle may also exhibit an illuminated malfunction indicator lamp (MIL) with diagnostic trouble codes (DTCs) P0420, P1450, P0443, P0452, P0456, P0460 and/or P2196. Some 2012-2014 Focus vehicles may exhibit inaccurate fuel gauge indication and/or inaccurate distance-to-empty notices.

Are there fuel economy gauges that are inaccurate?

The only problem is that the gauges are inaccurate. In fact, Edmunds testing reveals that one such gauge claimed fuel economy 19 percent higher than the actual result. Across two tests in seven different vehicles, the gauges were 5.5 percent inaccurate on average, according to data gathered by the editors at

What does the Edmunds fuel economy gauge show?

In the Edmunds test, the fuel economy meter was compared to the actual gas mileage the car delivered. Fuel economy gauges, which show both average and current fuel economy, are standard equipment in 92 percent of 2011 vehicles, according to Edmunds data.