Declining MPG

[Wings720]

Recently my MPG is going down.

Considering doing straight pipes and a cold air intake. What other maintenance items should I do as well?

 

[OR VietVet]

How old are the tune related components and what brand are they? What fuel do you use and what octane? Driving habits? Stock set up, gearing, size of tires? Colder out now and do you warm up engine before driving and if so, for how long?

 

[Joseph Garcia]

You have 2 posts on this topic, so I'm not sure which one is going to be the permanent one.

How much of a drop in MPG, and over what period of time has this MPG drop has this occurred.

If the MPG loss is significant (at least 3+ MPG), and nothing else in your driving environment has changed (city/highway ratio, speeds, etc.), then you should start some basic troubleshooting. Knowledgeable folks on this Forum will help you out.

Until you address you MPG issue, thoughts about straight pipes and CAI are irrelevant.

 

[MassHoe04]

If upstream O2 sensors are providing bad numbers to the computer, the computer will tell injectors to increase fuel until satisfied. That is just one of several possible causes for increased fuel consumption... There are others.

Can you look at live data for the O2 sensors and the fuel trims and report back with some pics of the scan data?

 

[Excel]

straight pipes drowe like made but im all for a good exaust system,ditch the cats,CAI
and a tune

 

[Doubeleive]

check the cat's when they start to fail one of the signs is poor fuel economy. right before mine failed I was loosing a solid 2-3mpg

 

[Rayyy]

In addition to what everyone else said, have you checked if my maybe one of your brake calipers isn’t sticking… Are all of the rotors equally warm after a drive?

 

[Wings720]

No tune. Stock everything except rims and tires. Brakes are good. I’ll plug it into a scan and get that data.

 

[rockola1971]

Have any codes set? Seen a flashing Check engine light lately? Year, Make, Model and 8th digit of vin?

 

[93M6Formula]

No tune. Stock everything except rims and tires. Brakes are good. I’ll plug it into a scan and get that data.

What size tires? If anything other than stock did you correct the speedometer so you can calculate correctly?