Insane Fuel Economy After First DIY Oil Change?

For my 40,000 mile maintenance I decided to take on the task myself (with Castrol 0W-20), rather than further enriching the dealership. I of course removed the air dam in the process, and initially noticed the expected one mpg drop in gas mileage (from 16 to 15). Three thousand miles down the road (with the air dam still off), I'm actually hitting numbers close to 18, under the same city driving/daily commute conditions. I'm certainly not complaining here, but wanted to eliminate the possibility that I screwed something up...

 

Well, 15-16 is a little low for a 3rd gen V6, so you’re up to where you should be now. I doubt you screwed something up.

 

It's called an anomaly.

 

I'm a stock OR (so no air dam) and get 20-21mpg. That's going 60ish up/down roads in Appalachia. I get similar mileage on the highway (little lower in winter). Have been using 0w20 the entire time. Unless you put no oil in or too much and it's not leaking out, there's nothing to screw up.

 

Happy Friday TW

 

It’s fine. I average 20-22mpg on the highway depending on traffic and I’m on 33” tires.

If I hit an exceptionally flat stretch of highway with no traffic, I have done almost a full tank with an average of 24mpg. Nothing weird about your numbers other than maybe being a tad low.

 

Probably got some better gas somewhere?

 

Same gas as always. Another possibility i was thinking about would be tire pressure, but that has actually gone down a couple of psi with the coming of cooler weather.

 

Sounds to me like your truck is broken in and starting to balance out the averages.