Does Diesel fuel mileage drop drastically in cold weather? My mileage wasn't bad during the summer but has really dropped significantly in the colder weather. I was getting about 16mpg in the city and now it's down to 11.5mpg. <br>No physical leaks and accurate keeping of records of fuel consumption.

 

I believe that it is the winter blend y'all have to use up there. At least that is my understanding from the guys that live up that way.

 

Here in Iowa it gets pretty cold. This time of year we are blending fuels and using No.1. No.2 doesn't work below -10 and sometimes down to zero. Blending and cold weather combined with what's need to move all that mass exacts a cost in fuel mileage. I've experienced 3.5 to 4.0 mpg avg decrease in colder months. YMMV

 

Here in Iowa it gets pretty cold. This time of year we are blending fuels and using No.1. No.2 doesn't work below -10 and sometimes down to zero. Blending and cold weather combined with what's need to move all that mass exacts a cost in fuel mileage. I've experienced 3.5 to 4.0 mpg avg decrease in colder months. YMMV

 

I usally loose 3mpg in the colder months.<br>Aaron

 

I've dropped about 2 to 3 -- keep some howe's diesel treat and howe's meaner power kleaner in every tank (or your choice of additive) -- not sure if it'll bring you back up a couple MPGs or not, but at least the diesel treat will keep it from gelling! ;D <br><br>Tony

 

Thanx fellerz fer da cluez. I'll try those ideas and get to ya with the results. HONDO

 

I figured it was the engine advancing the timing a little more since the colder air is denser.

 

sheeeeeit bigblue<br>i just thought it was the CWA's or no.1 that caused poor mileage. we need to know more about the timing thing. however, it really helps to plug in at &lt;15 deg f. that alone will get you 1-1.5 better during the deep freeze.

 

The number 1 fuel is thinner and you get less power out of it. Your idle time increases to warm your truck up. Put a cold front on it helps the engine to stay warm. I think the ideal outside temp is around 35 degrees and running number 2 diesel. When the weather gets 30 below and colder your mileage will really drop.

 

I've dropped 3.5 to 4 mpg since it got cold.

 

Rimfire, I have no idea about the timing. I just know that cold air is denser, and sense it is denser, you can throw more fuel in. The more fuel you throw in, the more fuel you burn. The more fuel you burn, the worse mileage you get. I've dropped maybe 1-1.5mpg. Nothing big. It doesn't get cold enough hear to run #1. Most, if not all, stations are still running #2.

 

I've noticed a 3-4 mpg drop due to the winter blend. It could also be because I slid the fuel plate forward and cranked the star wheel forward and now I can't keep my foot out of the radiator! ;D ;D