https://www.theautochannel.com/news/...ess005435.html
In 1997. Nielsen directly measured households, and estimated viewers.
Event / Network: Rating / Households / Viewers
* Daytona/CBS: 8.6 / 8.3 / 20.8
* Texas/CBS: 6.6 / 6.4 / 16.0
* Atlanta/ABC: 5.5 / 5.3 / 13.3 /
* California/ABC: 5.5 / 5.3 / 13.3
* Rockingham/TNN: 5.4 / 3.6 / 9.2
* Richmond/ESPN: 5.3 / 3.7 / 9.3
* Indianapolis/ABC: 5.3 / 5.1 / 7.7
* Darlington/ESPN: 5.2 / 3.7 / 9.3
* Charlotte/TBS: 5.0 / 3.5 / 8.8
* Bristol/ESPN: 4.8 / 3.4 / 8.5
* Martinsville/ESPN: 4.8 / 3.4 / 8.5
* Dover/TNN: 4.8 / 3.3 / 8.2
* Pocono/TNN: 4.8 / 3.3 / 8.3
* Michigan/CBS: 4.4 / 4.2 / 10.6
* Talladega/ESPN: 4.1 / 2.9 / 7.2
I didn't know that TNN drew so many viewers.