USA Today's Nate Ryan (@NateRyan) tweeted Tuesday that the final TV rating for Honda Grand Prix of St. Petersburg on NBC Sports Network Sunday was a 0.26 with a viewership of 388,000. The broadcast presumably faced stiff competition from the NCAA basketball tournament. There was also an F1 race before IndyCar and a NASCAR race after it Sunday.
Comparisons to last year are difficult since St. Petersburg (also the opening race in 2012) was on ABC. The 2012 race on ABC drew a 0.9 final rating with about 1.28 million viewers.
The first race on NBC Sports Network in 2012 was the second race of the season, Barber Motor Sports Park. It drew a 0.25 final rating with 218,000 viewers. The third race of 2012 at Long Beach drew a 0.46 rating on NBCSN with 468,000 viewers.
UPDATE: Below is IndyCar PR's fun with numbers news release (first mentioned by Speed Geek in the comments below). A note on the difference between a "coverage" rating and a "household rating": A "coverage" rating measures the number of households that were capable of getting the program that were tuned to it. A "household" rating measures the number of households in the entire U.S. that were tuned to the programming. Even households that don't get NBC Sports Network on their cable or satellite are included in this number.
From IndyCar PR:NBC Sports Network's coverage of the Honda Grand Prix of St. Petersburg delivered a 0.38 coverage rating and 0.26 household an increase of more than 50 percent vs. the network's first race of 2012 (0.25 coverage and .17 household) and the best for an IZOD IndyCar Series season opener on NBC Sports Network since 2009.
The race, won by James Hinchcliffe, delivered 388,000 viewers, a 78 percent increase over the NBC Sports Network's first race of 2012 (218,000). It was also the second-best season opener for NBC Sports Network's IZOD IndyCar Series coverage behind the 2010 race from Sao Paulo, Brazil (411,000).