Cox is an auto dealer servicing business. For that matter Automotive News is primarily oriented to dealers since they are the largest group of subscribers. Both provide dealer inventory data, although Automotive News maintains more widely available data on dealer and consumer incentives, vAuto is Cox Automotive's dealer software arm. Oddly they rarely describe their actual sources, so ambiguity reigns.
The best way to reconcile those with Tesla is to take manufacturer days on hand, generally somewhere between 20 and 30 days, and add that to dealer days on hand typically targeted at roughly 60 days for floor planning financing. For importers, roughly 45 days has been an historical target.
To compare with Tesla one would add 30 days mfr to dealer 60 days to arrive at a typical 90 days to compare with the Tesla 20-25 days.
These numbers reflect reality that is not often disclosed in totality because manufacturers, importers/distributors and dealers are three distinct legal entities, although the importer/distributor ones exist in some but not all cases.
So, to actually calculate typical numbers one adds Manufacturer inventory days on hand (in quarterly reports, sometimes in footnotes) to dealers days on hand ( available easily for public dealer groups. The importer/fistrutor dats is rarely available publicly. Luckily for Tesla a single number it it!
In years past I have been always surprised about the lack of transparency for this data. The only consistent recourse in the US has been Automotive News in recent years, but the Cox people have been presenting the data in a more easily consumed format. It always has surprised me how poor the OEM data actually has been, and how often it has been misleading.
How good it would be were all the OEMs to report data so comprehensively and legibly as does Tesla. Tesla makes data public that some do not even have internally. J
Just remember that nearly all OEMs are more like assemblers and wholesalers than like integrated manufacturers. At least the sales data tends to be accurate.
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