10 mpg winter fuel??? any one else

[zrain25]

i use to get about 14 mpg around town in the summer now in the winter im getting about 10ish. i also just put on 33in mud tires in the summer i had stock size ats. any one else getting 10 mpg in the winter. im thinking about changing the air filter and fuel filter???

[JSchuricht]

You have a lot of factors to look at. Filters are a good start. The larger tire will not help plus it will throw the speedometer and odometer off which in turn gives you a false MPG reading. 4MPG is a bit extreme for #1 but 1-3 MPG is not unheard of when switching from #2 to #1.

[BubbaJ]

Ive noticed i've lost about 2mpg since we started getting colder weather.. Although I do not know if they've actually switched to winter fuel here in south Texas yet.

[Zaairman]

Are you calculating the difference in tire size?

[zrain25]

no im not how would i go about doing this. the truck runs geat i dont think its any injector issuses starts right up in the cold

[Term3]

Normal to get lower fuel economy with winter diesel that's why a lot of big rigs have tank heaters and heated fuel lines so they can keep using summer diesel a lot longer.

[Zaairman]

Originally Posted by zrain25

no im not how would i go about doing this. the truck runs geat i dont think its any injector issuses starts right up in the cold

You need to figure out the % difference in tire size...

Tire size calculator

Then, whatever the difference is, add that % to your miles driven. And make sure you fill the tank up all the way.

[zrain25]

im not good at this math stuff im sure if i tried hard enough i would get it but... it says is 3.7% slow

[zrain25]

im going to start useing the gps for my miles

[bruce51d]

you also let it warm up more and idle more when its cold out. when youre sittin still and the engine is runnin youre gettin 0 miles per gallon