So yesterday, I reset my trip meter when I put on gas. I did a 7 mile drive home (no highways) MPG was around 54. This morning, my husband pulls the car from the garage to the driveway to install my name plates. When I start the car, I noticed MPG was 41. What could have caused the sudden overnight shift from 54 to 41. I only drove 3 miles to work since then so it is hovering around 42. Could the cold morning start to back up from garage did something? Could he have left the power switch on (and it shut off automatically ) Thanks in advance.
You have not driven the car for enough miles to achieve a higher MPG. Ig you only drove 7 miles and averaged 54mpg then allowed the car to idle and then backed it out of the driveway you were getting 0mpg. That is enough to drop your MPG pretty drastically. Just keep driving the car. By then end of your tank you'll be back where you expect it to be.
I think the heat was running, by the way, if power switch was left on, does it turn off automatically? I am thinking he left it running as he was installing the name plates.
If the car was left on (READY mode), the ICE will start and stop to keep the traction battery charged. Did you or your husband notice a strong exhaust odor inside the garage in the morning? If so, he left the car on and your gas mileage would drop significantly overnight. And, as F8L said, you haven't put enough miles on the car since the fill up to give you an accurate MPG reading anyway.
Between the gas station and home, you burned (7 mi) / (54 mpg) = 0.13 gallons. When you checked the gauge this morning, after hubby moved it, it had burned (7 mi) / (41 mpg) = 0.175 gal, meaning an extra 0.045 gal was burned somehow. Did hubby let the car warm up? That sounds about like my normal extra fuel consumption during the warmup process (while moving), and much less than the 0.06 gal it burned sitting in its parking space recently while I was scrapping ice of the windows -- and that got it only to 125F, not a full warmup. The more miles you roll up since last resetting the gauge, the smaller the numeric MPG hit with each warmup. But the amount of extra fuel burned each time should be about the same.
Yes, doing the math I realize the drop is not significant however I did get some good tips on warm up and not letting the heat run too much. At this point, I guess I should not worry about MPG (with other cars, it would be so much worse..so I am not complaining). Again thanks all for all the insight.
