Plummeting gas mileage

I had my oil changed, and replaced my front breaks over the weekend. since then, my gas mileage has dropped significantly. My driving habits, and commute haven’t changed at all. This week I was averaging around 15 MPG with a low of 11 MPG. In the past after I was averaging from 18- 21 MPG. Any ideas?

 

Brakes dragging?

 

What oil did you use, and do you notice brakes dragging?

 

winter gas... check brakes for dragging. Might be the calipers not releasing.

 

i used the same full synthetic Ive used in the past. would i hear or feel anything if they were dragging? It feels pretty normal, aside from the 11- 15 mpg.

 

not necessarily. You will get a burned brake pad smell if you are dragging and if your rims are excessively warm especially in the winter you might have an issue. Easy to check is jack one wheel up at a time and see how freely it moves.

 

thanks for the info. ill give it a try tomorrow if it stops snowing!

 

Question...Did you pull master cylinder reservoir cover when you pushed caliper pistons back?

 

not sure, i had then done at a local garage.

 

Not enough information to provide informative feedback about your MPG issue. Too many things can affect MPGs ie.. driving habits, tires, mods, weather/temperature, vehicle setup etc.... If brakes aren't dragging, then something else has changed.

 

I went with a larger wheel and tire about a year ago, and saw a small drop. since then, I havent changed much. I use the same gas, and more or less drive to the same mix of highway and city driving every day. its been cold, but it was worse weather before the oil/ break change.

 

If the brakes are dragging your wheels towards the center should be damn hot when you get where you are going. Especially if it is enough to drop you 5MPGs. That would be my guess. Jack it up and see if you can spin the wheels freely as well.

 

If you MPG dropped that much, you should notice or are doing something different. A 25-40% drop in MPG just doesn't simply happen for no reason.

 

Did you fill up at a different station?