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as the OP , do us who responded a favor...set your cruise control at 65 mph on a level freeway and report back to us what your instantaneous MPG is , averaged from both directions ..I suspect it should be high 20s/ low 30s
actual mileage gotten by two people driving same car , traffic flow speed of say 65 , and same road can vary even if each is " going with the flow " ....just one example how that can occur : if one drives with thin soled shoes, he can feather the throttle to keep up with traffic by just varying the pressure of his big toe ...if the other driver wears thick soled leaden boots , he is probably " driving by his ankle " and you can imagine how wasteful his throttle tip-in angles are ...again, both drivers just " going with the flow"....one driving almost on cruise control, the other running constant gas eating accel and coast " sprints " between 63-68 mph .
this simple time tested pneumonic works : pretend there is an uncooked egg placed between your foot and the throttle pedal and that will maximize your MPGs
30.9 mpg over 100 miles in southern Germany today in a '14 911/50 with power kit and 7MT. Cruise set on 75 mph and maximized 7th gear. No sport mode selected. Amazing car.
I noticed the OP used Fuelly calculations and it appears most everyone else used the car's computer. Aren't the car system notoriously "optimistic"? Has anyone checked "actual MPG" (Fuelly, log book/calculator, etc.) against the car computer? 10% high is a number that comes to mind for the car vs calculated.
I noticed the OP used Fuelly calculations and it appears most everyone else used the car's computer. Aren't the car system notoriously "optimistic"? Has anyone checked "actual MPG" (Fuelly, log book/calculator, etc.) against the car computer? 10% high is a number that comes to mind for the car vs calculated.
Anybody?
Why? You can trust the computer.
Next you will suggest diesel emissions are rigged.
I noticed the OP used Fuelly calculations and it appears most everyone else used the car's computer. Aren't the car system notoriously "optimistic"? Has anyone checked "actual MPG" (Fuelly, log book/calculator, etc.) against the car computer? 10% high is a number that comes to mind for the car vs calculated. Anybody?
My experience is within 2%. So about 0.5 mpg on a highway trip calculation. Most of that error is whether or not you pump extra gas into the tank after automatic shut off.
My C2S has averaged 28-30 on trips running with traffic. I have seen 32 on one 60 mile section along I-15 with light traffic around 80 mph. No Sport or Sport Plus and Start/Stop engaged for the coast feature. We can only get 91 (MON+RON/2) octane here in California, not the 93 preferred by the sticker on the gas flap.
I have averaged 24 mpg on the computer's third trip option left alone for the first 9999 miles.
Of course I have sunroof delete so perhaps the slick roof with no sunroof seams reduces drag
So using the on board data, 946 mile/14.6 hour trip from Fresno to Seattle, avg speed 68 mph, avg fuel consumption 28.6 mpg. That was at the end of last December in our C2s cab and I used cruise control quite a bit. We typically averaged 27.5+ on non-congested freeway driving (e.g., Seattle to wine country over Snoqualmie pass).
2014 911_50 with Powerkit: My consumption has not varied much from new - during Euro Delivery (first 3400km), avg consumption was 10.97 L/100km (25.75 mpg Imp, 21.44 mpg US).
The latest 2852 km (I now have over 10K km) 10.78/ 26.20/ 21.82.
Best tank - 8.13/ 34.75/ 28.93 (400km freeway slog).
All figures calculated from fuel used and distance driven (largest error is probably the accuracy of the odometer, of course). OBC reads similar numbers, within a small number of percentage points.
