Gas Mileage Just Decreased

So over the last 3 fill ups of my truck my gas mileage has drastically dropped. I was getting somewhere around 18.5 MPG, which isn't great to start with. The last few fill-ups have been 17.34 MPG, 16.77 MPG and today 16.64 MPG.
My truck is a stock 2011, Double Cab, Offroad 4x4, Auto, V-6 with 15K miles on it. The air and oil filters have been changed out recently, so that's not the cause. I check my tire pressure about every other week, so that's not it either. I always go to the same gas station and have never had this problem before. Since I've been a member of this forum, I have heard alot of people talk about a "winter mix" for gas. Could that be the case, even in San Diego.
Any suggestions or comments would be greatly appreciated.

 

Winter blend gas.

 

Winter in San Diego???? lol

So gas still costs the same but MPG is less......blah

 

Gasoline distributors send the same gas all over their region. These regions are often extensive and cover many different weather patterns.

San Diego may not get winter weather, per se, but I'm sure plenty of stations there get winter gas.

 

Why is this in the for sale section?

Best advice on gas mileage is keep your rpms below 2k when possible. Driving habits dictate most gas mileage numbers.

 

Ha, didn't notice til you mentioned it, but that's funny.

 

It's NOT in the 2nd gen section?!??!?!?!?!

 

Dammmit. I don't know how this ended up in the for sale section. I wanted it to go to the second gen section. Can I move it now?

 

Maybe the gas. Or the conditions in which you drive for a given tank. Or how you drive for a given tank. Or all of the above. I've found that my truck MPG swings all over the place more so than any other vehicle I've ever driven. At best I've seen 19.7 and at worst 16.9, and every tank is a surprise. My best was actually on a winter blend. Most of the time I can't pinpoint why at all. Sometimes when I expect high MPG I get low and vice versa. Been trying for far too long to find the "sweet spot" to maximize MPG. What seems to work one tank fails the next. Very frustrating.

 

For the last 6 or 7 months, my mileage stayed pretty constant at just above 18 MPG. The only time it changed was when I towed my trailer. Now over the last few tanks, BAM, it drops almost 2 MPG.

 

My mileage goes for a shit right around this time of year till it warms up again .

 

fixed it for ya

 

Wat

 

Winds too play a significant role.

I've noticed the past two days going to school on the highway heading south, i'm facing strong winds and my SGII doesn't show anything more than 22MPG

Going back home heading north i'm not going against the winds anymore and i can easily hit 28-30MPG instantaneous read outs on the SGII.

 

... my first suspicion would be winter "blend" gasoline, ..but also the fact that in colder weather your "cold-start" and engine warmup period will use more fuel..

 

Im thinking winter blend...mine did the same...i only fill on base too so i know its not brand of gas that us doing it

 

Thanks for the comments. I think I'm gonna go with the winter blend story since nothing else has changed at all.

 

Why do people buy trucks then bitch about the mpgs???? If you cant afford the gas get a car