[aerohead]

I'll keep this simple to begin with, and we'll get into the weeds later.
1) In 1973, Professor Edward F. Obert, University of Wisconsin, and author of my textbook, Internal Combustion Engines and Air Pollution, essentially debunked any notion of a so-called 'throttle-stop testing technique ( which will be referred to from here on out as the 'technique' ) by describing SAE standard practice for road-testing, explaining how vehicle quanta are officially obtained, and providing the formulas which 'define' values of interest, associated with the 'technique.'
2) The first 'elephant in the room' is thermal equilibrium testing, of which all SAE is conducted, and no mention, nor requirement for it is broached within the methodology laid out for the 'technique.'
3) It has been scientifically demonstrated that, testing results, obtained under conditions of thermal nonequilibrium can produce results which are off by up to 67%, with ZERO modifications to the test vehicle.
4) Thermal nonequilibrium testing introduces seven easily identifiable unknowns into test results.
5) In order to thermally stabilize all pertinent parameters of a motor vehicle under road test requires a minimum of 30-miles of driving at 50-mph immediately before testing begins.
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From SAE Paper 780613, the second elephant in the room involves:
6) Testing from a 'cold-start', depending on ambient temperature, which can introduce a data discrepancy of of 27% at a distance of 3.6-miles.
3% discrepancy @ 21-to-32 miles distance.
14% overall average.
With ZERO alteration of the test vehicle.
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Also from SAE 780613:
7) The ambient temperature of the 'short' cold-start test can corrupt the results by 53%-to-36% depending on OSA temperature.
8) Engine oil, coolant, transmission fluid, and differential lube do not reach equilibrium viscosity until the 30-miles @ 50-mph is achieved.
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9) SAE Paper 780596 explains improvements obtained from SAE SE rated, lower viscosity engine oils, and GL-5 transmission and differential lubes, however, they cannot compensate for the lion's share of losses from 'cold-start' conditions.
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10) Hucho et al's SAE Paper 760185 essentially debunks, by default, any notion of a 'technique,'
11) OEM 'torque' ( measured both at thermal equilibrium and 'best-torque' ignition spark advance ) is structurally defeated by a 'stopped' throttle.
12) 'Best-torque' is a function of bmep, which is governed by BSFC, and as defined as bmep= power-times 1224,divided by displacement times engine rpm, once a vehicle changes speed, the consequent change in engine rpm, by default, violates 'best-torque', by definition. Hucho et al. provide no caveats/ conditions for 'exceptions.'
13) The very act of reducing drag, lowers engine load, altering all the 'momentary load points' which previously DEFINED the engine map.
14) 'The new load point normally is associated with a higher BSFC.' Hucho et al..
15) Torque is not 'constant.' It falls because bmep fell, as BSFC climbed.
16) Hucho et al. demontrated that 'potential fuel economy improvement' from a Cd reduction could be compromised by 50%, by not changing the gearing to move the engine back to the original 'load' at any specific rpm. ( And bear in mind that this is all recorded at thermal equilibrium and best-torque ignition timing, which is defeated when the throttle is 'stopped.')
17) No 'correction factors' can be applied to the 'technique's' partial-load tests, as atmospheric pressure is no longer controlling or limiting engine output.
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18) ' automotive engineers prefer the specific fuel consumption as a parameter to indicate efficiency.' Professor Obert. page-94.
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19) SAE J1082a, Road Test Procedure, SAE Standard Practice, and Gino Sovran et al.'s SAE Paper 810184 & SAE Paper 830304 expand on Hucho et al.'s SAE Paper 760185. Again, no caveats, no conditions, no exceptions.
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20 ) In his PREFACE to his 1987, Aerodynamics of Road Vehicles, 2nd-Edition, Wolf-Heinrich Hucho admonishes: '(T)he vehicle aerodynamicist must refer to a large amount of detail resulting from earlier development work.'
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21) We know that Mr. Edgar has been in possession of Hucho's 2nd-Edition, which would make Hucho's 1976 research available, as Fig. 3, from 1976, reappears as Figure 3.7. page-90, in the 1987, Aerodynamics of Road Vehicles.
22) Why Mr. Edgar so vigorously defends the 'technique', while having been in possession of official SAE testing evidence which is counter-factual to his thesis of 'constant-torque' escapes me.
I'll be happy to 'go deeper'. Please limit questions to 'technical', 'quantifiable'
aspects of the 'technique.' ( nothing subjective, anecdotal, etc..)