My 03 Honda CRV has ben getting 21 mpg consistantly. All of a sudden the mpg has dropped to 15 mpg. My driving habits/city/highway have not changed. the only thing that has changed is a brand new set of Nokian all season tires (highly recommended) and the outside air temp is getting much colder. anyone have any ideas?
Are the Nokians properly inflated? Is the engine reaching normal operating temperature (warming up) quickly?
Colder temps and a change in fuel additives (during winter) cause a mileage reduction among many other things.
What method do you use to calculate your mileage?
If the Nokians have a substantially higher rolling resistance (very likely) than your previous tires, that factor combined with lower temperatures could certainly account for the drop in gas mileage.
Cold mean lower mileage due to the temperature, the effect on the engine and the change in fuel formula.
I am also wondering about how you measure the mileage. We read from a lot of drivers who’s methods are … well let’s say primitive.
I am guessing the Nokian WR’s. My experience is maybe at tops a 1MPG drop in mileage on a Subaru WRX(23MPG car) and Honda Civic. I do see another 1MPG drop due to winter fuel and cold etc with it.
Make sure the tires are properly inflated to what is list on your driver door jamb(typical place) or a sticker in glove box.
The engine does warm up quickly. Tires are inflated to recommended pressure of 35 psi. and I calculate the mileage by dividing miles driven between fill-ups by # of gallons pumped.
Have you been letting the car idle a little longer when you start it in the cold? If so, that alone could be a significant cause of your mileage reduction.
Then here is the most likely reason: For your last fill-up, the pump was slow to shut off. You pumped in more gas than you normally do. This reduces the calculated mpg even though your CRV runs perfectly normal.
A slight drop in mpg in winter is also perfectly normal, but this large drop is merely a mathematical illusion. I am convinced there is nothing wrong with your car.
No sir, Absolutely no change in my driving habits.
My only other guess related to tires is the installed size may be the wrong one on the wheels reflecting the wrong mileage traveled.
How long(many fuel fill ups) has this lower mileage trend occurred?
Tir size is the same as the ones removed from the vehicle. 3 fill-ups.