major MPG drop all of a sudden

what would cause my MPG's to drop off all of a sudden? 2006 DC 4x4 SR5, was getting approx 22-24 mpg, now am getting 15 - 16 mpg... seems to run the same but is using way more gas....anyone else have this problem?

thanks

 

No warning lites on the dash?
I would look at 02 sensors first. Could be going bad and dumping more fuel into the system.

 

Your fuelly sig says 19 mpg, so at 16 you are not as far off as you think. Either way you are not giving us enough info to give ideas. At 3 mpg off normal, could be a batch of bad gas, have you been in 4wd a lot lately, towing anything, fuel filter, could be a whole host of things....

 

Are you using 4wd alot? It kills my mileage...

 

x2

 

x2 i went from 22 to 15 mpg after a few times using 4wd. I would imagine cold start up temps, low tire pressure due to cold, and winter gas but were you getting good mileage before winter hit?

 

Winter gas blend .... in Canada ...... in the winter

4x4 all the time doesn't help either

 

Eat to much over the holidays? =P

Probably some bad gas unless its consistent, then I would guess o2 sensors are screwing with your mix.

 

Could it possibly be that you converted KM vs. MILES? I noticed that you're from Canada and just a thought.
Think about it, 15 Miles = 24.14 Kilometers. Possibility? No disrespect here, I'm merely throwing something out for you. If you really get 24 mpg I want to swap out my US ECU for a CAN ECU!

I've got the same truck, live in Nevada and the absolute best tank of gas was purchased in Salem Oregon and I got 17.5 MPG on the highway with 2 motorcycles in the back. Turns out it was summer and the refinery was at the same station I bought the gas so I'm thinking it was the "fresh" batch. Typically in the winter I get 15.5 to 16 mpg.
Happy New Year all!

 

i'm getting 14-15 on a fresh tune up, tons of air in my tires, and driving like a 89yr old grandma, winter gas sucks and my aerodynamics suck

 

Started using defrost all the time? Winter gas? 4x4? All could contribute.

 

ya, thanks guys, I'm chalking it up to winter, winter gas, defrost, etc, not in 4x4 much as the roads have been clear... but i suspect its just due to winter...

 

yea the defroster wont help either since it uses the compressor

 

U know what i have been getting shitty milage too, I actually went through my truck yest and chrcked diff oiks, spark plug gaps, clean maf sensor, grease u joints ckean filter, I was scully thinking of changing o2 sen and getting a maf sensor. Hmmm maybe its time to invest in a maf, so ut can help my milage, just don't tell the wifey!!

 

Sounds like you've been letting the truck warm up before you get in and take off. My money is on the gas burnt up idling.

 

Defrost?

 

That's why you should do the diy mod to eliminate this, one of the best things I've done to my truck

 

I thought the compressor was only running if you're on defrost and you have the A/C switch lit up?

 

Nope, if u use defrost, u use ac, but the ac light won't be on

 

your right in the ballpark for mpg in the winter...these truck run rich as PIGS