dentureman

I have a 2008 ES350,71000 miles and drive the same 101 miles every day. Started at 27.5 mpg from day one and just yesterday noticed I am getting 26.2 mpg. Why and what can I do about it.

QuachmanES

iTrader: (4)

Is that mpg figure based on the car's trip computer? The car's computer isn't always accurate or reliable. It seems like a small enough difference that it might just be the computer's margin of error.

The most accurate way to calculate miles per gallon is to divide the miles traveled per tank of gas by the amount you fill up to full.

kyledye25

Have the spark plugs been replaced yet? I know they say they are good till 100k but I always changed them before that mark. But that is a small margin. Many things could change it that much. If it keeps dropping then maybe worry about it a bit.

PFB

With the numbers that you are posting, your apparent MPG drop is so small that it should be considered to be totally INSIGNIFICANT, and well within any margin of error.

There is really nothing to worry about.

Phil

BoostedE21

You could have just had a head wind one day, or dirt on your paint causing added wind resistance, or low tire pressure, or you could have passed someone aggressively once, etc. Or it could just be the engine pulling the timing as it gets hotter outside for the summer time.

A variation 1 mpg is not something I'd spend even a dime looking into. It's just not significant.

EngHead44

It turns out. The 1 MPG your worried about may be caused by a very large problem I discovered. YOU DRIVE THE CAR! It is gonna get old, it is gonna break in, it is gonna wear. Sorry to burst your bubble but there is a reason cars with 20k miles behave differently than the same car with 200k miles.

Megafast13

Mine changes based on my driving style. Were you in a hurry that day or something? Otherwise it could just be the wind, tire pressure, etc.