weather and gas milage?!?!

[Grocery Getter]

Switching to winter blend sucks in the Midwest.

I have no idea if they do that in Arizona.

I don't know if they do for sure.....I just assumed they do but maybe not since it doesn't get below freezing until you hit 5 or 6000ft....

dunno

 

[tx tahoe z71]

Switching to winter blend sucks in the Midwest.

+1 on that notion

But cooler air = denser air, and denser air = more power. My tahoe is a whole different animal when it gets cooler, I swear I pick up 50hp. Blowers love the winter!

Your mileage might be bad b/c of the warm up time (on short trips) and the winter blend gas. Beyond that, maybe change your fuel filter, O2's, clean your air filter, seafoam, change your spark plugs

 

[tybardy]

well... i take better care of the hoe then I do my own body. Fuel filter has only about 15k on it, air filter is consistantly cleaned, O2's are fine. This is litterally a noticable 2-3mpg difference since the temps dropped signifigantly.

Although it is known that cooler air is denser, which means each square inch of air actually has more O2 molecules which gives a larger combustion. Cooler air does have a hard time combusting then its warmer counterpart. (this is just what I have gathered from my education over the years) i would not have thought anything of it if my milage went down .5 or so. It went from an average of 20.5 mpg to 18.5 mpg under the exact same driving conditions.

 

[Rollin Thunder]

milage of 18.5 is wonderful though. I can only sqease the yukon to 17 on long trips (like 800+ long) and the silverado never leaves the 13-14 mark. Vette never leaves single did gets half the time though lol.

---------- Post added at 02:29 PM ---------- Previous post was at 02:28 PM ----------

simple question. have you pressed auto 4x4 on accident?

 

[Crazy Al]

I'm with RT on this one, I never leave the 13-14 area, and the highest I've seen in months is 14.6....Noticable for you, but I wish I had your 'bad' mileage lol. Odd thing is, when I bought the truck a bit over a year ago I used to average 16.5. Oh well.

 

[yooformula]

I always thought when the vehicle is tuned during warmer climates and the temps drop, that it increases timing and power but does use more fuel as it runs rich. maybe try cleaning the o2's or pull a few plugs and see what they look like.

 

[rigo_jones]

IDK if yours does this. But when its cooler here, My truck tends to have more power. Like if its 80 out. It has less, but when its between 50 and 65, it like adds 20 hp and I get less MPG because of this.

i notice this too. when the motor is cold the ecu uses a different map with more timing and is why you feel the extra power. by adding timing the motor will reach its normal operating temp. and burn more gas.

 

[tybardy]

plugs are good, recently replaced. All scheduled maintanace is way over done... i can check but i seriously doubt that the problem is with the little things (i.e. pluggs, wires, filters, etc) as I am pretty maticulous about upkeep.

It was tuned during the summer months here in Phoenix. not sure how much effect that has coming into winter.

Tire pressure is 30psi cold... just checked.

And to clerify, I get 20+ mpg's because I do about 95% of my driving on the highway

 

[Rollin Thunder]

my truck was tuned a year ago. But last October it was 40 out. This October its been average 85. So IDK how that affects vice versa performance.

 

[tx tahoe z71]

Have you gained weight recently? That could be it, maybe go on a diet




JFWY

Have you been filling up at different stations that cut their gas with an ethanol blend, like 10%? That's going to drop it a decent amount, but no more than a 5% difference.