Reviews and reports can be written in many styles and some (i.e., anything by a Murdoch publication or broadcast) are not worth my time. I tend to avoid either overly solicitous or backhanded reviews filled with opinion fluff that hides the physics and math. Curiously, your listing of specific I-Pace features, free from references to the Tesla products, are pretty good and appreciated. But that was not the first two paragraphs of the Detroit News article.
Another example, I was turned off by the 48 V, Continental reports because they were full of inflated claims about the efficiencies gained . . . hubris comparing them to high voltage hybrids like the Ford, Toyota, and Hyundai hybrids. It wasn't until I saw their electrically heated, catalytic converter for diesels that I realized Continental is trying to salvage small diesel cars.
The 48 V systems lack the energy needed to even approach a proper hybrid BUT if you are trying to bring back the small diesels, ~2.0 L, 48 V makes sense. After Bosch and the diesel manufacturers cheated, bringing back small diesels is a fools errand, good money after bad, but it is their money. It was the style of 48 V advocacy that turned me off plus lack of technical content.
I'm looking forward to your I-Pace review once you get it in your hands. About the same time, the EPA
may have the roll-down coefficients so we can understand the drag power as a function of speed. Let me share an early example started in October 2005:
This chart is from our first, 2003 Prius:
- X-axis - steady state speed
- left Y-axis - calculated MPG scale based upon 31% ICE drivetrain efficiency and drag power
- blue line fuel consumption w/o drag power
- gray line fuel consumption with drag power and vehicle overhead
- right Y-axis - calculated drag power as a function of speed
- red line drag power needed to sustain speed
- validation benchmarks plotted on graph
With this chart and subsequent benchmarks:
- Documented that engine suffers efficiency loss if over filled with oil.
- Found the maximum range speed, ~20 mph +/- 5 mph.
- Found a highway speed, 'knee in the curve', green diamonds: below 70 mph get 52 MPG, and; above 70 mph get below 40 MPG.
- Tested a thermistor hack that fooled the control laws that the engine coolant was hotter than actual. This prevented unnecessary engine running and gave more than 100 MPG at the optimum speed.
Source:
http://hiwaay.net/~bzwilson/prius/
I am hoping once you get your I-Pace you'll benchmark kWh consumption as a function of speed. Then maybe we can find a similar set of benchmarks for the Model 3. I already have them for our BMW i3-REx and Prius Prime.
Bob Wilson