Hmmmmm..... Thats odd.... Its possible that the engine is not fully broken in yet.. But I think your milage should be a little better than that... Dumb Question Here... Please forgive me.... Are you sure you were in OverDrive while crusing the interstate? This is where we get our gas milage at... Strange though, an almost new car with no miles on it and the milage is a bit low... Next time you fill up with fuel fill up all the way and run it down to less than half a tank and fill up all the way again and see what the milage is, But stay out of the Afterburner.......
I always leave it in Drive so, yes it was in overdrive.
I have always filled it up to the top and always wait until almost empty until I fill it up.
I keep an accurate log of every fill-up and then always reset the average mileage on the DIC. I've filled her up 54 times since new.
Before the pulley I was averaging a best of 11 L/100 Km (21 mpg) to a worst of 15 L/100 Km.
After the pulley, I average 16 to 19 L/100 Km (12 mpg).
I'm sure it has something to do with my addiction to the new found power and my lead foot. WOT for me is a norm.
Now that I think of it, the best mileage I got was when I was breaking it in and feather footing it at the posted speed limit.
That is really really hard to do now.
When you've got an afterburner, how can you control the need....the need for speed.
I am also suspecting the drilled 180 stat has something to do with it too. I am usually just getting up to 180 degrees when I reach my destination and have to shut it down.
I have never been on a trip with it on the highway that lasted more than one hour long. So most of the time is stop and go and short trips.
I think the only way to average over 24 mpg would be a straight run in OD for 4 hours or a full tank.
I have a hard time believing Will did it playing at speed with his new pulley in hilly terrain.