= 28% total theoretical improvement over base from measured mechanical/aero mods
I'll be the first to admit this tally is flawed on several levels: 1) the weather conditions weren't the same for all tests; 2) the speed wasn't exactly the same for all tests (but close to 55 mph); 3) the effects of individually tested aero mods can't simply be summed because their effects interact with one another ... the car is probably more or less than 28% better with all the mods in place. But the car was never driven with all of them in place at one time and then without.
To do this comparison, I looked at 3 tanks in Firefly #1 which were predominantly city driving. When I was using that car, I wasn't employing coasting of any form, or P&G/codfishing, and there were none of the mods listed above.
Firefly #1, 3-tank tally: 1474 km, 83% city driving ... 5.2 L/100 km / 54.0 mpg (Imp) / 45.0 mpg (US)
Blackfly, 3-tank tally: 1724 km, 83% city driving ... 3.3L/100 km / 86.5 mpg (Imp) / 72.0 mpg (US)
If you do the math, that actually works out to a 60.2% improvement for the Blackfly.
The biggest flaws in this comparison are: 1) it assumes the "base" cars are identical (which they were on paper, but probably weren't in reality) ; 2) the Blackfly has some mechanical & aero mods on it that the other car
didn't have. Based on the values in the mods list though, we can correct for these mods:
- 5.2% transmission advantage
- 10.3% alternator advantage
- 1.2% aeromods advantage (calculated based on avg. city speed of 25 mph vs 55 mph for the tests)
- 6.0% rolling resistance (this is a WAG - the Blackfly has LRR tires and higher pressures than the first Firefly had)
-22.7% total deductions (this is actually a liberal estimate, because the Blackfly was not running alternator-less, nor with all aero mods, and the taller tranny was only in place for 2 of the 3 tanks)
= 37.5% estimated difference due to driving technique