I have a 2010 Mazda CX-9 Grand Touring with 80,000 miles on it. I bought it 2 years ago with about 50K miles on it. When I first got it, I would get alteast 300 - 320 miles on a full tank. Now I'm barely getting 240...and these are highway miles.
What's going on?
Any suggestions?
What are you guys getting on your CX-9.
did you try resetting the MPG computer ?
toggle the "INFO" button until you get to the "miles remaining" function
and hold INFO button down until 240 number resets and becomes "- - -"
do the same for "average MPG" function, hold until it reads "- - -"
I have a feeling you did a long stretch of slow local city driving or stuck in stop and go traffic
and it ran down the average MPG to 12 or 13 MPG
this has happened to me before and after resetting, I get my normal 16-17 MPG and 320 full tank
You have to drive like 5 miles on the highway after resetting and then the computer will display the true MPG for that 5 mile stretch.
also, I've done the following in the past:
1) check your engine air filter, a dirty filter will also decrease your MPG's
2) change gas stations or try higher gas grade, I know WTF ? but I swear there's this one gas station I avoid like the plague,
for some reason I always get bad MPG from that specific gas station, not sure why but I don't go there anymore.
3) reduce weight, get rid of anything heavy in the trunk you don't need
4) check wheel balance and alignment, any slight un-alignment will cause drag and make the engine work harder and decrease MPG
