Are you PDK? My long term average is right around 20, with a best around 24 on a tank. I don't try to squeeze more fuel in and just end my fill when it auto shuts to try and be consistent.
Oh...and I love your car. So nice!

 

What are your oil temps? You need to be about 228 to 232°F for optimum fuel burn and efficiency. You should easily be getting over 30 miles per gallon. Do you have fresh plugs and fresh engine air filters?

 

I didn't look, but I did keep it out of sport mode which I did have on during the previous trip, with similar results.
Like I said, I am not complaining, I didn't buy the car for efficiency. There must be a hit for the ducktail drag/downforce. I know the C4 also takes a hit with the additional rotating mass. Just interested to find out why I am not hitting the numbers others do. I have never hit a flatland/Midwest cruise. I live in the foothills of the Blueridge and there isn't much driving I do that doesn't involve hills of some sort.

 

Filters? Plugs?? Again, I have to ask.

 

I last see these items replaced at 40K, 28 months ago. Not sure if they did it @ 60K since I had no report. I picked the car up during the start of covid and didn't get a report, just a key handoff in the middle of the parking lot. I don't think these items are on the 60K service.

 

Then you're good for another 20,000 miles or 20 months, whichever comes first. It was not required at the 60K service.

It must be the hills and terrain in your area. Lucky you.

You have a very rear car. C4 with aero package. Cool beans.

Enjoy.

Happy Thanksgiving.

 

Yes, a C4 with aero is a rare bird, so to speak. I liken it to a mini GTS without all the performance, but all of the flair. I have to go over hills to get to town, so most of my driving. I have to go over a mountain to get to work, both ways

 

I have a 2014 Manual 991.1 with power kit (extra 30 hp). If I drive in Normal mode and keep the speed at or below 80 mph, I regularly average 30-31 mpg. Tires pressures on comfort and not full load. A/C on. I will switch to Sport Plus to pass if needed.

 

Exact same here. And a cabriolet.

 

I'm getting about the same here on long runs. Shorter weekend drives I'm not even worried about because the right foot is always heavy on those fast runs through the mountains!

 

The EPA highway test loop has an average of 48 mph so not exactly real World.
Even their high-speed test loop doesn't average much more.

https://www.fueleconomy.gov/feg/fe_test_schedules.shtml

 

Yep, PDK. I could probably do better but the right foot doesn’t listen.

 

So I got my return results from the 300 mi trip. This time with zero around town driving, which my previous calculation included maybe 50 mi worth. It was 25.2, so not that far off 27 rating. I can see a spoiler eating 1-2 MPG with a 68mph average.

 

So....out of shear boredom, drove to Palm Springs and back. 310 miles, average speed 76.3mph, 29.4mpg, sport mode, valves open on the Soul. Now back to the hole.

 

Auto Start On! Is that a new option? I almost forgot there is button like that in my car!!! Thanks for the reminder. Another reason to go for a test drive...