Dropping MPG's

Truth! Longer I drive the better MPG I can get. Driving to work, 12-15 minutes- MPG sucks. Takes almost that long for the truck to warm up to operating temp and by then I am there and shutting it off. Ill get 13ish in that situation. Now if I am driving an hour, 45-70mph, I'll get 16-17

 

I understand the comments about hand calculating etc but this is going by the dash readout which like I said has gone down over the past 5 years. So whether the computer is correct or not there is still a change.

Brakes were recently done. All was good but I will go over them again, you never know.

@Terndrerrr so if towing mpg's aren't a good reason to buy a diesel can you tell me some reasons that are?

 

Full disclosure: I didn't read all the previous responses so I apologize for any repeats.

Things to consider aside from the maintenance suggested by others:

1. Are you hand calculating mileage, or using the computer? Computers have a bit of variance.
2. Have you had your speedometer recalibrated for the bigger tires? If not, then you are getting better mileage than what the computer reports because you are travelling further with each tire rotation than what it is calculating. Example: If you increase your tire's circumference by 10% you are going 10% faster and travelling 10% further than the odometer, speedometer, and fuel computer will show.
3. Is your truck Flex Fuel, and if it is, are you using E85? Ethanol is "cleaner" but you get worse mileage using it. Non ethanol fuel will get better MPGs every time.
4. Related to point 3, there has been a guberment decisions to use more corn in gas to try and keep prices down, so this will be tanking mileage for any fuel that isn't ethanol free.

 

I am using the computer. Actually I have been watching my throttle and I am up to 14.7mpg on the computer. Also took my dirty deeds exhaust off and went back to the factory system.

Truck is not flex fuel.