The way the range is quoted for all EVs is about the same as printer manufacturers quote life of a cartridge.
So EPA (Environmental Protection Agency, USA) determines EV range on treadmill, under varying urban and rural driving conditions after an over night charge. Testing continues until car is no longer able to run. The test is performed indoors and at room temperature, with only a single occupant (i.e. driver) and no additional luggage
The NEDC (New European Driving Cycle, EU). is also an indoor test devised in the 70s and phased out since it provides very limited set of useful data. So we'll ignore what it did, since it is no longer relevant (hasnt been relevant since the late 90s)
the NEDC was replaced with WLTP (Worldwide harmonized Light vehicle Testing Procedure) . It is still an indoor test with controlled temperature, but does take into account use of heater, AC etc. But the scenarios arent as realistic as EPA so the WLTP range is higher than EPA. WLTP collects from the US, EU, India, Switzerland, Japan and South Korea but NOT china.
The Chinese have their own standard as WLTP excludes China, the CLTC (China Light duty vehicle Test Cycle). It is a sort of a derivative of the WLTP with few differences; the top speed is less, there are more stops and the idle test duration is longer. Do note that CLTC is a Chinese govt. standard not by Chinese EV manufacturers.
All tests are on a flat surface, no elevations, no sudden accelerations etc etc. You can read more about each test on respective websites.
Of the standards the EPA is the closest to what you might expect in real life, but even that is higher since it does not take into account additional passengers, luggage, deviation from strict temperature controls in an indoor environment.
CLTC offers the greatest range figures (as it is the least stringent, with slowest speed),
IF CLTC range is considered 100%, WLTP will be 80%, while EPA will be about 70%
So if CLTC range is 100km, WLTP will be 80 and EPA 70.
You can extrapolate it to whatever range various cars quote.
And finally coming back to the printer cartridge analogy:
HP uses IEC 24711 standard to tell you, you can print 1000s of pages using their cartridge, when in real world it is closer to 100s.
The test assumes a certain % of page area to be covered with printed material.
So if you cover say 50% of your area with printed text, take that number and divide it by 5. So 50/5 is 10.
Now check how many pages the manufacturer quotes for their cartridge, lets say 2000. So divide 2000 by 10 which gives a grand total of 200 pages per cartridge!!
