Big Drop in Fuel Mileage

[clintusaf]

So My mileage has dropped from a consistent 17 to 12-14. I havent done anything to the truck, except installing a BTS trans about 6 months ago. I maintain my tire pressure monthly with little need for adjustment. I also know that a drop in mileage is expected with the heat in summer, but this is my 4th summer with my truck and I've never experienced this much of a deviation. What would be some things to check? Please help!

 

[DaveBen]

Actually, the Summer Fuel gets better mileage over the Winter fuel. More calories per gallon in Summer fuel. I have not noticed that big of a drop in my fuel mileage. I am seeing a 1.5 to 2.0 mpg drop. I was getting 17.4 over the last 3 months, but I do not drive very far.

Dave

 

[clintusaf]

Thats right. I got them mixed up. ha. well, thats means my mileage has taken even more of a drop than I thought!!

 

[BIG JOE]

So My mileage has dropped from a consistent 17 to 12-14. What would be some things to check? Please help!

Air & fuel filters..

Joe

 

[clintusaf]

changed both of those about three months ago.

 

[BIG JOE]

changed both of those about three months ago.

You might wana pull the fuel filter anyway.. and take a look at it ? You may have gotten a slug of sediments.. during a fill-up ?

Is this lower mpg's a recent thing ?

Joe

 

[Tman123]

I tend to change the air and fuel at same time whether they need it or not. I only go about 3k to 5k miles until I change them. So pretty much every oil change lol. All apart of the maintenance

Travis

 

[dpantazis]

check your brakes?

 

[clintusaf]

Didnt think of that. I havent noticed any difference in them. What would cause them to affect my mileage?

 

[Dieselpwrdredneck]

If they are hanging up the drag would require more power to move the truck more power=more fuel it would be somewhere for ya to start