So I 've spent the last few months testing the various modes of the RCF and recording their respective MPG results. For the record my car is complete stock, I live South Los Angeles County (near Long Beach), and work in East Los Angeles County (near Pomona).

the test:
56 mile round trip commute to work/home. 33 miles to work, 23 home.
I have to take my daughter to school in the morning, she attends a G.A.T.E. Academy School 10 miles southeast of our home and work is 23 miles northeast of our home, this makes the drive to work a bit different than the drive home, but it does help in making ideal conditions for a mixed high/city test.

To work: 10 miles highway >65mph, 16 miles surface street avg. 42 mph (35-45mph zones, 17 signals, avg. wait at signal 1:15, 7 miles back roads >55mph 6% uphill grade for 1.2 miles, 3% downhill grade for 3.5 miles, flat 2.3 miles.
Return home, 2.7 miles surface street to and from highway, average speed 24 mph 4 signals, 3 stop signs. avg. wait 0:52, 20.3 miles highway, avg. speed in rush hour 38mph.

each mode was run for 1 month (20 work days) the car was not used for any other purpose but back and forth to work. That mode was used exclusively for the entire duration of the test. The calculations were made manually by figuring the total miles / total fuel. for that given cycle, the on board MPG computer was also reset for each test and matched my manual calculations with a very small margin of error. Each fill was approx. 14.5 gallons of fuel, vehicle usually filled within a 1-2 miles of the low fuel light activating.

ECO mode Avg. MPG
Vehicle Computer reports 24.2
Manual Calculation reports. 23.9
Avg. miles on 14.5 gallons 345 - 350
3 fill ups.

Normal mode Avg. MPG
Vehicle Computer reports 20.4
Manual Calculation reports. 19.9
Avg. miles on 14.5 gallons 280 - 290
4 fill ups

Sport mode Avg. MPG
Vehicle Computer reports 18.4
Manual Calculation reports. 17.9
Avg. miles on 14.5 gallons 250 - 260
4 fill ups

Sport+ mode Avg. MPG
Vehicle Computer reports 16.1
Manual Calculation reports. 15.8
Avg. miles on 14.5 gallons 220 - 230
5 fill ups


There is an 8 mpg drop between ECO and Sport+ mode.

in ECO the car shoves itself into 8th gear as quickly as possible and holds that gear as long as possible, I watched it hang in 8th coasting from 65mph down to 37mph, additionally it keeps the car in Atkinson cycle as long as possible, basically anytime the car is not under load. in Sport+ it holds each gear at higher RPMs for longer, and I only saw it go past 6th gear once with I was cruising above 90mph.

I also found it interesting that the on board computer seems to report 1/2 mpg more than manual calculations consistently.

While most people don't care because really who buys a car like the RCF for mpg? the fact is that for daily commuting, there is a 100 mile per tank difference between ECO and Sport+ which for me is 2 more round trips to work, or 2 more days between fills, also consider the difference of 2 additional fill ups riding around in sport plus mode over the same time frame, that's an additional $90-$100 in fuel that month.

Your results may vary based on the fuel and terrain where you live, CA fuel is crap, and the roads are as well.