Oil change and drop in MPG

[gpbst3]

I had an oil change and tire rotation on Monday at a local dealership. Since then my MPG has dropped about .7 mpg.

Same tank of gas, same driver, same roads.

I never noticed a change before. Wondering if they could have used a thicker oil? Any other explanations?

 

[Neurobit]

Coincidence.

 

[Scram1500]

Less than 1 mpg isn't much of a change. How is your tire pressure? I know there is global warming because the talking heads on the TV say so, but the frozen bird bath this morning tells a different story. As did my tire pressure which was low due having checked a few weeks ago when it was 72, not 32

 

[Jako]

I had an oil change and tire rotation on Monday at a local dealership. Since then my MPG has dropped about .7 mpg.

Same tank of gas, same driver, same roads.

I never noticed a change before. Wondering if they could have used a thicker oil? Any other explanations?

Was temperature taken into account?
I notice my mileage goes down with cold weather until the Ram reaches operating temperatures. I am aware of winter gas. It seems to me the Ram does not like cold weather as far as mpg. The tolerances for motor, transmission and rear drive are all "tight" and oils need to reach appropriate operating temperatures to get optimum mpg.

I also would not use the vehicle mpg display as an accurate indicator.

 

[IvoryHemi]

How many tanks of gas have you used in 4 days?!

 

[Richard320]

Is this instant or cumulative mpg? I'd expect cumulative to drop. How long did the truck idle at the dealership? Were you sitting in line waiting with it running? Could the tech have let it idle a good long time to ensure the oil filter didn't leak? Did they wash it? Maybe it sat in line idling and then ran the whole time it was being pulled through the wash. And you don't know how leadfooted the tech was if he test-drove it after the rotation.

 

[mikeru82]

Have you checked the oil level? They may have overfilled it.

 

[gpbst3]

It has been colder lately but I never had a drop in MPG all winter. Im on the same tank of gas all week. Im using the average MPG computer on the screen.

Maybe I will just reset the MPG and see what happens.

 

[Neurobit]

It has been colder lately but I never had a drop in MPG all winter. Im on the same tank of gas all week. Im using the average MPG computer on the screen.

Maybe I will just reset the MPG and see what happens.

There are so many variables you can't control that you will never get the exact same MPG on two tanks. .7 is within the margin of error.
Now if you saw 2-3 MPG difference, that would be different.