The obd2 sensor I my p71 tells me 29.3 lifetime average. Whether that is life of the car, or since I plugged in the module, I'm not sure. Watching the real-time number break 60 coasting downhill is fun.
Mathing it out at the pump,I find 24-26 a more realistic number.
Lots of short trips under 10 miles each way and lots of loud pedal don't help those numbers though.
I've done a lot of fuel mileage work both on the highway and on the chassis dyno using a variety of very accurate methods for measuring consumption. In pretty much every vehicle built in the last decade that I have experience the on board computer is accurate within a couple of percent.
To the OP's point, the biggest factor effecting fuel economy is the driver. Take a look at what the hypermiler folks are accomplishing.
Note: hypermiling is extremely annoying to other motorists and is not endorsed in any way by APEowner, his friends or affiliates.
In reply to irish44j: The engine (design) in my Fiesta is not exactly a spring chicken. Been around for a few years.
I wonder what the 1.0L eco boost would do ?
Rodan
Reader
6/28/17 10:58 a.m.
The computer in my '04 Dodge Cummins tow pig is wildly optimistic. The one in the wife's NC is much more accurate, but still optimistic by 1-2mpg. Miata tires are not stock size, so factored into calcs, but it was also slightly optimistic when it had stock tires.