How Can I Get My Gas Mileage Back?

[jtupper]

I have noticed over the last couple of years that my MPG has decreased. Where I used to get about 14 MPG consistently in the city, I now only get about 12. I have replaced a lot on this truck in that time, none of which helped with gas mileage. Here's a list as best I can remember...

 

knock sensors

O2 sensors (front only)

catalytic converters

fuel pump

fuel filter

plugs

wires

PCV valve

air filter

 

On top of these, I have also had the injectors cleaned (in place) and seafoamed the top end. WHat else can I be missing?

[Jennabear]

Clean your MAF and throttle body.

[mhenshaw]

Maybe the gas you have been using in the last couple of years now has ethanol added to it. 10-15% ethanol will kill you mpg.

 

I can't remember when ethanol was added around here.

[old-chevy-dude]

driving habits?

roads (curvy or hilly?)

increased stop and go traffic in your area?

 

tires inflated correctly?

What size wheels/tires (larger wheels or fatter tires reduce MPG)

type of gas you use (non-top tier usually nets lower MPG) and that Ethanol crap will definitely reduce MPG.

 

 

you didn't mention if you have any after market stuff (throttle body spacer, Cold Air Intake, headers, cat-back exhaust, Chip/Tuner) all of those will reduce MPG as well.

 

 

Lots of things can affect it, so you need to be a little more specific about what mods you do or do not have and how and where you drive.

[PhilB]

If you have never serviced the transmission or rear diff, you might want to look in to that. Also - have your driving habits changed over the years? i.e. harder acceleration, driving faster. What about traffic patterns? Are you driving in more traffic? Are you catching more stops than before? What about tires? Different tires have different rolling resistances that can affect your mpg. So can the tread pattern, more aggressive tread pattern will drop your mpgs. Also the quality of gas you're buying can impact mpgs.

 

Hope this helps you. Good luck!

[dlstewart01]

Maybe the gas you have been using in the last couple of years now has ethanol added to it. 10-15% ethanol will kill you mpg.

 

I can't remember when ethanol was added around here.

 

We have had ethanol in our gas around here for at least 20 years.

[HawkScot]

We put larger tires on our 98 Yukon, resulting in 4% lower mileage (yukon odometer shows less miles than actually driven). We know the speedometer and odometer are off and just calculate for it.