After the last time I filled gas, my 2013 es300h mpg dropped to 22mpg. No other parameters have changed, tire pressure, weather conditions, city driving, same octane rating gas refuels, driving speed, braking etc. Typically when I fill gas, the mileage goes up to 44mpg initially and once the tank is 1/4th, it averages out to 37mpg with no change in driving habits. I have about 85K miles on the odometer. Initially, I thought it was the battery, but It doesn’t look like the battery is the issue. I regularly watch how the battery discharges so this time too there is no change in the discharging. I started coasting a little more, very light on the gas pedal, turned on eco mode which helped me get it up to 31mpg. Any idea what is happening?

 

Very short trips?

 

about 20/25 miles a day

 

ok so that’s not it. If you were doing 8 miles a day then poor mileage would be normal.

 

You might have just got a tank of bad gas from the station. It's not uncommon, I once had to drain my tank and replace injectors because the "gas" I bought turned out to be 40% water.

I'd run the tank down as low as you can, then dump some Blue (Marine) Stabil in the tank and completely fill it with gas (from a different station) afterwards, problem might go away quick after that.

 

Wow 40% water in gas is insane! Lemme tryout your suggestion. Thank you!