Presented here is the list of Penske's stock car wins from the Racing Reference site. The Penske Racing website has its own tabulation presented here. The three-race discrepancy stems from three Jeremy Mayfield victories in 1998 and 2000 with a #12 listed with Michael Kranefuss as owner, this after Kranefuss merged his team into Penske's organization.
For those with knowledge of history it seems hard to believe that Penske, long a dominator of Indycar racing, has been so successful in NASCAR, especially given those periods over the years when Penske's stock car efforts didn't look that stout, notably when he started in the 1970s. Mark Donohue grabbed Penske's first NASCAR win at the 1973 Winston Western 500 at Riverside.
It was not until Bobby Allison joined Penske Racing at the 1974 Firecracker 400 that Penske's team began to prove itself a legitimate NASCAR contender.
Allison's first win with Penske came in the 1974 LA Times 500 at Ontario Motor Speedway. The following April came Bobby's most astonishing win with Penske.
The Mercuries were sold to George Elliott and his son Bill began to race up front in the Grand National ranks in 1978, while the Chevys Penske had built formed the basis for Rod Osterlund's team, driven in 1978 by Marcis. Penske campaigned twice in 1980 and rookie Rusty Wallace stunned everyone by finishing second in the Atlanta 500.
Penske began getting back involved in NASCAR in 1989 with feelers to Rusty Wallace, who was involved in a contract fight with team owner Raymond Beadle; in 1990 Penske played a role helping Wallace acquire Miller Beer sponsorship, and at the end of 1990 Wallace went to Penske for a full-time effort. Their first win was in the chaotic 1991 Southeastern 500 at Bristol.
When Buddy Parrott was hired to be crew chief in the final third of the frustrating 1992 season it wasn't until 1993 and aerodynamic changes to Pontiac that the tandem exploded, winning four of the first eight races before Dale Earnhardt's cheapshot at Talladega derailed the Rusty onslaught of that season. Wallace still won ten races, and a very public break with General Motors and switch to Ford led to eight more wins in 1994, but a rash of late-season failures and Buddy Parrott's decision to leave wound up marking the end of this period of Rusty-Penske dominance. Wallace would win thirteen more races with Penske before retiring after 2005, and in 1997 he would acquire a teammate when Michael Kranefuss merged his team into Penske with driver Jeremy Mayfield.
The one that got away forever will be the 1999 Daytona 500 as Wallace was almost unpassable for 107 laps until the field almost wrecked with ten to go and Wallace got double-drafted out of the top nine.
In 2000 Penske Racing had a horsepower edge until at Sears Point NASCAR tore down one of their engines in front of rival teams, which angered Wallace but which had been overdue given NASCAR's open-garage policy dating to its very beginning. Also that year Penske signed youngster Ryan Newman. Jeremy Mayfield won twice in 2000 but fell out with seven engine failures and two wrecks and became more publically agitated at his lot with the team. After publically calling out the team for a chassis choice made at Kansas, Mayfield was gone from the team.
For 2002 Ryan Newman took over and won at Loudon, NH, but it was in 2003 that he exploded, winning eight races. This occurred during the 2001-03 period of high downforce and a harder tire than ever run before; because Newman was winning on fuel mileage to a significant extent (this atop wins by the likes of Kurt Busch that happened by skipping pitstops altogether and not losing speed on older tires) Penske's senior driver Wallace became ever angrier and lobbied NASCAR to cut downforce. It hurt Newman's firepower as he won just four more times with Penske; it also hurt the sport as multiple spoiler reductions, sway bar changes, and tire changes often badly hurt ability to pass and helped drive away popularity for the sport
Penske finally reached a racing pinnacle when Ryan Newman won the Daytona 500 in 2008. When Rusty Wallace retired Penske hired Kurt Busch, who'd been fired from Roush Racing late in 2005 on his way to three NASCAR suspensions over his career. With Penske Busch won ten races and got himself fired again at the end of 2011, this despite a mealy-mouthed "mutual parting" press release from Busch. While Busch was flaming out new teammate Brad Keselowski, signed on in 2010, was rising up, and in 2012 Keselowski stormed to the Winston Cup title, Penske's first. Two years before the championship, Keselowski pulled off one of the organization's most spectacular wins in the Busch Series 300-miler at Talladega.
For a team that was considered a part-time outsider outfit and which quit the sport only six years after it started, Penske Racing has authored a lot of success.