Is Cold Weather Effecting My Mileage

[tnlegendracer]

It just went from 50 to the teens in temp here in middle TN. I've noticed in that time that my mileage (still making same trips) has dropped by 1.5 MPG. The only change I've noticed is now the trans temp is barely moving off 100 (takes forever to do that), water temp is cooler and oil pressure is elevated.

Is it the temp or is this the way an injector begins to misbehave?

[precision37]

Most likely the cold. Your engine won't opperate at top efficiency till it gets fully warmed up. Cold engine oil, trans fluid,rear end lube, etc. all add up to more power needed to do the same work.
More power=more fuel used.

[More Power]

Cooler weather affects diesel fuel economy in at least two ways. 1- Here in the northern tier of the country, winter #2 diesel fuel is a blend of #1 & #2. There are less BTU's in #1, so there's less energy per unit volume and your mileage could drop a bit as a result. 2- The various fluids in the truck's drivetrain are more viscous, causing more drag - consuming more fuel.

It also takes longer for the engine to warm up, which reduces its efficiency somewhat till the engine reaches operating temp. You'll notice more of a drop if you do more short trips.

Don't look for problems..... smile.gif

MP