Consumer Report city, highway fuel economy doesn't make sense

From the last page of http://www.consumersunion.org/Oct_CR_Fuel_Economy.pdf that I posted earlier

I presume they start w/a cold engine. It's unclear how long the stops are between the 6 runs and whether they power on/off between them.

 

Cwerdna,
I'm too lazy, but after reading the description of the CR test I wonder how linear a graph of car weight vs mpg would be grouped by engine/drivetrain type.

 

Cu does help with useful/less information and small details other mags would either skip or scoff at. Helps to look at a purchase from all angles, to me at least.

I have found their '275(?) trip' mileage to be pretty accurate for the typical 'suburban' mileage measurements. Both my former cars and wife's cars were either dead on or within a mile or two of CU's trip figures for tanks of mixed driving commuting and in the burbs.

The Prius is over by 6 - 7 mpg (50 - 51 now vs. CU's 44 in test) but if I put the Prius in power mode, did not use any mileage tricks that I've learned driving it, and also goosed it around more like my older cars, it would probably be pretty close.