2015

In September 2014, it was announced that Ambrose would return to V8 Supercars to race a Ford Falcon FG X for DJR Team Penske, formed by NASCAR owner Roger Penske, who was interested in expanding his Team Penske organization to start a team in Australia and as a result merged with Dick Johnson Racing, becoming DJR Team Penske

Ambrose started in 2015.^[7] He debuted at the final round of the 2014 season,^[8] driving the #66 Xbox-sponsored FG Falcon.

He began the 2015 season on a low note, starting near the back of the field in every one of the race. His best finish was 12th in the 3rd race at the Clipsal 500 in Adelaide.

In March 2015, Ambrose took a temporary leave from DJR Team Penske in order to improve his practice with V8 Supercar racing, being replaced with Scott Pye.^[9] He returned for the three-round Pirtek Endurance Cup as Pye's second driver, claiming an eighth finish at Surfers Paradise race 1.

Ambrose did not return as a full-season driver in 2016.

Post-racing career

In a 2017 interview, two years after his abrupt retirement, a journalist for Motorsport.com interviewed Ambrose at his brand-new Lodge near Launceston, over his shocking retirement from V8 Supercars. In the interview, Ambrose said that the ultimate reason was that, "My time was up," and that he was "Putting the team first" in making his decision to step aside from the car after only two races.^[10][11]

In the interview, Ambrose stated, "The deal with Roger and Team Penske and Dick, it was really formulated a year and a half beforehand where a conversation occurs you say 'if you ever did that Roger I'd love to drive for you', and you kind of leave it at that. And then a year and a half later the phone call comes and it's on. And it's like 'oh shit, is this really what I should be doing now? Because I'm feeling pretty tired and worn out from my American thing'. I thought it'd be right, I'd come home and it'd work itself out. And then the situation that DJR was in at the time, where they were in this transition phase – and they still are, they're getting better and better each race, you can see their progression, but it takes time. I knew it. So when you come back, and I'm struggling to adapt from NASCAR back into a modern V8, the testing restrictions, and the tires are hard, and I'm confused and tired from the States … and then you see 'Fuck, to get out of this is going to take three years, to dig yourself out of this hole'. And I realised that I'm not the right person for that team in the phase that they're in. I need to get out of the way. And that's what I did."^[10]

In an interview with the same journalist for Motorsport.com, Roger Penske said, "It was a call that he made and we supported him; he was very gracious in the way he handled it, and quite honestly I respect him. It reminded me of Rick Mears when he told me in 1992 that he didn't have it in his belly any more to go as hard as he needed to, and that it was time to move on. Marcos didn't say it that way, but he realized the sport had moved on and maybe he was not able to make the commitment we needed over a longer period of time".^[11]

Ambrose made a brief return to racing at the 2023 Bathurst 6 Hour, which is part of the Bathurst Motor Festival held during the Easter weekend. He raced as a co-driver alongside George Miedecke and Tim Brook in the number 33 Ford Mustang.^[12] He retired from the race after the Mustang's 10-speed automatic transmission failed after two hours into the race.^[13]

2006

At the first V8 Supercar race of 2005, Ambrose called a press conference on the Saturday morning to announce to the top staff and fans that he would leave V8 Supercars at the end of the 2005 season to try to make a career in NASCAR.

In 2005 Ambrose signed his deal to compete under NASCAR and Ford Motor Company signed Ambrose to participate overseas in the United States with Wood Brothers/JTG Racing in the NASCAR Camping World Truck Series in 2006 to start his career. However, Ambrose had to wait until part way through the 2006 season to begin. NASCAR did not clear Ambrose to race the NCTS' first three races, as they were held on intermediate to high-speed ovals, and like fellow Wood Brothers/JTG Racing driver Bobby East, Ambrose was not cleared to start in the faster races. Ambrose made his Truck Series debut on 1 April 2006 at the Kroger 250 at Martinsville Speedway, qualifying 20th and finishing 33rd after being caught up in an incident unfolding in front of him.^[14]

Ambrose is the first notable Australian driver in a NASCAR sanctioned event since Dick Johnson in 1990 and Australian based New Zealander Jim Richards in the mid 90s.

Ambrose made history by finishing third in the O'Reilly Auto Parts 250 at Kansas Speedway on 2 July 2006. This was the first time a non-American driver has finished in the top five of a truck series event since Canadian Ron Fellows won on the Watkins Glen road course on 26 June 1999. He also took the lead in the opening laps, becoming the first Australian to lead laps in Camping World Truck Series competition. The next week, he made further history by scoring his first pole position for the Built Ford Tough 225 at Kentucky Speedway,^[15] and then leading the most laps in the race itself, though he finished 19th.^[16] Ambrose finished 3rd in the Toyota Tundra 200 at Nashville Superspeedway after qualifying 11th.

Ambrose reached as high as 19th in the championship points,^[17] but finished the season 21st overall and 3rd in the Rookie of the Year standings, despite having missed the first three races of the year.^[2]

2007–10

Marcos Ambrose during the 2007 Ford 300 at Homestead-Miami Speedway.

For 2007, Ambrose stepped up to the NASCAR Nationwide Series, driving the No. 59 Kingsford Ford Fusion fielded by Wood Brothers/JTG Racing. In the first two races of the 2007 season, he finished on the lead lap, in 16th and 25th, on tracks he had never previously raced on. In the third race of the season, the Telcel-Motorola México 200, Ambrose finished eighth, his career best at the time. having gained several positions in the last few laps of the race. He followed up his 8th-place finish in Mexico City with another top 10, finishing 10th in the Sam's Town 300 at Las Vegas. He recorded a career best Nationwide Series finish of sixth after starting third at Dover in May.

At the 2007 NAPA Auto Parts 200 Nationwide Series race at Circuit Gilles Villeneuve in Montreal, Ambrose was the dominant driver of the day, having led for 37 laps. After a caution period had finished, Ambrose had well-known Sprint Cup regular and Dakar Rally racer Robby Gordon behind him. At turn 3, Gordon successfully made a pass on Ambrose and then the yellow flag came out. At the next corner, Ambrose rammed the left-rear of Gordon's car, spinning him out under yellow. Due to a caution being brought out earlier because of a large crash behind them, Gordon sped back behind Ambrose. During the caution, NASCAR officials declared that Ambrose was actually leading at the moment of caution (even though video footage appeared to show otherwise) and that Gordon had not maintained cautious pace by stopping in the middle of the race-track after the spin. Therefore, officials ordered Gordon to move back to 14th position for the oncoming restart, but he refused and was subsequently black-flagged. When they restarted with 2 laps to go, Gordon intentionally ran into the back of Ambrose at turn 2, spinning him around. Although the win slipped away, Ambrose dropped down the field but recovered to finish in 7th. Following this incident, Gordon apologised and made a peace offering to Ambrose in the form of a ride for the Watkins Glen road race, in Gordon's No. 77 Camping World Ford Fusion. However, qualifying was rained out and the field was set by owner's points, and the No. 77 did not make the race.^[18]

In September, Ambrose skipped a second opportunity to drive the No. 77 car because his wife Sonja gave birth to their daughter Adelaide on the same day as the Cup race at Dover. Ambrose finished the 2007 season 8th in the points standings, highest of any driver not also competing in the Cup series, and finished second behind David Ragan in the Rookie of the Year standings. On Sunday 20 April 2008 Ambrose was involved in a racing incident with Boris Said in the Busch Series event in Mexico. Ambrose admitted "getting into the back" of road course specialist, Said, causing Said to wreck and ruining his chances at a race where Said has consistently finished in the top 10. After the race Said claimed that he was not mad at Ambrose, but wanted to apologise to (Ambrose's) crew chief, Gary Cogswell because it was going to "cost him a car," implying that Said will wreck Ambrose intentionally next time they find themselves on a NASCAR track together. Even though NASCAR said that Boris just wrecked himself by getting loose, and that Ambrose has repeatedly apologised, in numerous subsequent public appearances, Said has not backed down in his threatening of Ambrose, at one point suggesting he would not apologise but preferred to "beat (Ambrose's) ass".^[19]

However, later that year at Watkins Glen when Ambrose was leading the NBNS race, in the final five laps he took the lead and with 2 laps left he raced behind the bumper of a lapped Boris Said. Ambrose's crew chief Gary Cogswell ordered Ambrose to not pass Said believing that Said still had a grudge against them after Mexico City. The fans, Ambrose, his team and among other NASCAR drivers were surprised when Boris Said did not commit his revenge before Ambrose later won the race. To this day Said has not explained why he did not crash Ambrose when he had a good chance and it still remains unknown why Said did not perform his revenge.^[20]

2008 No. 21 Sprint Cup car

Prior to the 2008 season, Wood Brothers Racing and JTG Racing split into two teams.^[21] Ambrose was scheduled to drive for both teams in Sprint Cup competition in 2008. He was going to run twelve races in the No. 21 car for the Wood Brothers and another four in the No. 47 car for JTG Racing. However, due to various issues he only ran 11 of the 16 planned races. He ran well in the Toyota-Save Mart 350 at Infineon, qualifying 7th out of 47 drivers and was running in the top three, but his No. 21 spun through the famous Turn 11 hairpin and blowing his transmission, finishing a disappointing 42nd in the 43-car field. He attempted to make his second career Sprint Cup start in the Lenox Industrial Tools 301 at New Hampshire, but failed to qualify, qualifying 45 out of 45. Again, 43 cars would start, and again, he attempted to qualify the 21 car.^[22][23] He also drove the full Nationwide Series schedule.

He almost won the 2008 NAPA Auto Parts 200, dominating again like in 2007 but when a thunderstorm blew the track, Ambrose tried to slow for a pit stop. Nonetheless, his car slid across pit road too fast unable to stop because of the waters; thus he earned a black-flag for a pass-through penalty. He ended up third in the final results behind race winner Ron Fellows.

On 15 July 2008, it was announced that Ambrose would run the full 2009 cup schedule with JTG Racing with a new partnership with Brad Daugherty. The team was renamed JTG Daugherty Racing.^[24]

Ambrose got his first Nationwide Series win on 9 August 2008 in the Zippo 200 at Watkins Glen after his heartbreak at Montreal the previous week (See above). The next day, he finished 3rd, after starting in 43rd position in the Centurion Boats at the Glen, behind winner Kyle Busch and Tony Stewart.

Ambrose drove the No. 47 Toyota in the 2009 NASCAR Sprint Cup series, after forming a technical alliance with Michael Waltrip Racing and Toyota Racing Development.^[25] Ambrose also drove the last 4 races of the 2008 Sprint Cup series in the No. 47 Toyota, after NASCAR agreed to change MWR's car number from No. 00 to No. 47.^[26] Ambrose entered Homestead with the No. 47 in the Top 35, earning him a guaranteed start for the first time in his career. However, a bad finish at Homestead put the team back out of the Top 35, so Ambrose would have been required to qualify on time for the first five races of 2009. Eventually, the team earned a Top 35 exemption after a number of teams merged. Ambrose is ineligible for 2009 Rookie of the Year consideration because he ran 11 races in 2008. Ambrose finished 10th in the 2009 Food City 500, despite losing a cylinder with about 100 laps (50 miles) to go. Ambrose would back this Top-10 finish up by posting 4 more in the first half of the season. Ambrose got his second straight Nationwide Series win at Watkins Glen, his second in two years as he held off Kyle Busch for the win. He followed up with a 2nd place in the Sprint Cup race at the Glen. The following week Ambrose dominated the Nationwide race at Montreal, but on the final lap, he was passed by Carl Edwards when Ambrose jumped over the curb too high, and Carl Edwards zipped past him for the win. Ambrose picked up a top ten finish at the 2009 Sharpie 500. Ambrose charged hard from being 1 lap down with less than 100 laps left, to finish in third place behind Kyle Busch and Mark Martin.

Ambrose's No. 47 car during the 2010 Toyota/Save Mart 350

The 2010 season was a myriad of troubles for Ambrose. Engine problems, unlucky crashes and pit road troubles plagued his racing season. However, in the Zippo 200 at The Glen, Ambrose won his third straight Watkins Glen he held off Joey Logano and Kevin Harvick to win. Since the win, he started to gain some form, recording a top 10 at Atlanta and a top 5 at Richmond. At the Toyota/Save Mart 350 at Sonoma, Ambrose led 35 laps, and held a ten-second lead over Jimmie Johnson. His lead got erased by a caution on lap 104. During the caution, Ambrose turned off his car's engine to conserve fuel, but was unable to restart it. As a result, Ambrose attempted to return to his spot, but was forced to fall to seventh on the restart due to not maintaining a particular speed during the caution,^[27] and finished sixth. After the race, Ambrose stated, "I was leading the race and had trouble getting the motor cranked back up a little bit there, and NASCAR made the call. I was trying to save fuel and the motor shut off. It didn't recrank the way it should. I didn't stop rolling, but it is what it is."^[28]

2011

Ambrose's No. 9 car at Pocono Raceway in 2011

Ambrose announced on 17 August 2010 that he signed a multi-year deal with Richard Petty Motorsports to drive the #9 Stanley/DeWalt Power Tools Ford Fusion. He finished 37th in his first race with the team at the Daytona 500, after being crashed out of contention in a 15 car wreck in turn 3 on lap 29. He did finish the race. He went on to have an impressive race at Phoenix running in the top 10 for most of the day. In August, Ambrose won the rain delayed Heluva Good! Sour Cream Dips at The Glen on 15 August to rack up his first career Sprint Cup Series win by passing Brad Keselowski and Kyle Busch with two laps to go. Ambrose further vindicated his road course abilities, backing up under a week later by taking an emotional victory at Montreal in the Nationwide Series, during the NAPA Auto Parts 200. The 2011 season continued to be his career best as he recorded 5 top 5 and 12 top 10 finishes. Ambrose finished the 2011 season 19th in the final point standings.

2012

Ambrose (9) battling Jeff Gordon in the 2012 Kobalt Tools 400

Ambrose returned to Richard Petty Motorsports for 2012. In February he almost won the Budweiser Shootout with bump-drafting help from Keselowski; but lost the lead just as he took the white flag to Tony Stewart and eventual race winner Kyle Busch. Ambrose said after the race that despite losing the Shootout the race was his best performance on a restrictor plate track (although he also had several top-tens at previous plate races, such as a 4th-place finish at Talladega in the spring 2009 race).

Ambrose started the season with a 13th-place finish in the Daytona 500, and in the spring races, collected six top-twenty finishes and two top-ten finishes. In June, he posted the fastest qualifying speed in NASCAR competition in 25 years, winning his first career Sprint Cup pole in the Quicken Loans 400 at Michigan International Speedway at a speed of 203.241 miles per hour (327.085 km/h), the third fastest pole speed ever in NASCAR. Ambrose finished ninth in that race.

The following week, Ambrose won the pole at Infineon Raceway but only led about 10 laps before he had to pit thus putting him in the top ten for the rest of the day. He finished 8th.^[29]

Returning to Watkins Glen, Ambrose started fifth and dominated part of the race but was passed in a three-wide move by Kyle Busch with 20 laps remaining. When the white flag was about to wave he saw that Busch was slipping in oil; in the entrance to the esses he and Brad Keselowski passed him; Ambrose then saw that Keselowski was slipping in oil too and he took the lead in the final turn, holding off Keselowski for the second time in a row and defending his win from the previous year. Ambrose was very emotional about his win due to his father seeing it on television in a hospital for an illness and due to his luck that day. The win moved Ambrose up one position in the standings from 18th to 17th. Ambrose still has promised the racing world for a future oval win since his #1 goal currently is to prove he can win at places other than road courses.

His victory caused local company Mac Tools to offer Ambrose multi-year sponsorship which Ambrose's boss, Richard Petty, approved of. Mac Tools sponsored Ambrose in a few races for 2012 and throughout 2013.

2013

Ambrose during the 2013 Toyota/Save Mart 350

To start the 2013 season, Ambrose had 11th-place finishes in both the Sprint Unlimited and the Budweiser Duel. Ambrose drove in the top ten for a part of the Daytona 500 but when Kevin Harvick, Kasey Kahne and Tony Stewart crashed out of the race, Ambrose slowed down to avoid being involved in the accident, causing him to drive for the rest of the race further back in the field. He finished in 18th place. He recorded another 18th-place finish at Phoenix and a 22nd-place finish at Las Vegas.

Ambrose was on his way to a good finish in the NRA 500 at Texas Motor Speedway before crashing with Jeff Burton and finishing a lap down. Then, a couple weeks later he had a frustrating day at Richmond International Raceway when his engine failed early and he finished 42nd. He recovered for a 14th-place finish at Talladega, one of his top 2013 finishes.

In the Coca-Cola 600, Ambrose reached a top ten spot in an unusual style. On the final lap, Carl Edwards was about to hold off Ambrose for the tenth position, but got loose in the final turn to the finish line, causing Ambrose to slip by to steal the tenth spot and lock Edwards out of the top ten finishers. This fight for tenth place resembled a reverse style of Ambrose's race at Montreal in 2009, which ended with Edwards getting by him on the final lap.

At Sonoma, Ambrose led the first laps of the race getting by pole-sitter Jamie McMurray at the start of the race. He finished in 7th place. At Loudon, Ambrose fought Harvick in the opening laps for a top ten spot. In a corner, Harvick rammed Ambrose's right rear causing Ambrose to spin out; he would finish in 33rd.

At Watkins Glen, Ambrose won the pole after breaking the track record with a lap speed of 128.241 mph (206.384 km/h), breaking the previous record held by Juan Pablo Montoya's speed of 127.020 mph (204.419 km/h).^[30] Ambrose led 51 laps but on lap 60, he pitted under caution. He restarted in 15th and never recovered. With 3 laps left while running in 8th place Ambrose tangled with road-course rival Max Papis, ending his hopes to win three races in a row at the Glen. Ambrose was visibly upset with Papis in the aftermath, furiously tossing his steering wheel at the in-car camera, tossing his helmet hard through his window, and pointing his finger at Papis when Papis came by under caution.^[31] Ambrose finished 31st. Had he won, Ambrose would have joined Jeff Gordon and Mark Martin as the only drivers in NASCAR history to win three consecutive races at the Glen.^[32]

Ambrose made a Nationwide Series return at the Mid-Ohio Sports Car Course's Nationwide Children's Hospital 200.^[33] Ambrose had to start in the back as he did not qualify the car. Ambrose made it up to third, but was then spun out numerous times, falling to 16th. He rallied to finish in 7th place^[34] but was spun out by Parker Kligerman after the checkered flag for previous contact during the race.

2014

Ambrose during the 2014 Toyota/Save Mart 350

Ambrose started with a seventh-place finish in the Sprint Unlimited, and an 18th-place finish in the Daytona 500. He then had 21st and 24th-place finishes at Phoenix and Las Vegas. At Bristol, Ambrose finished fifth in what was statistically one of Richard Petty Motorsports' best races to date, as teammate Aric Almirola finished third. It was Ambrose's first top five finish in a race since the 2012 Irwin Tools Night Race.

At Richmond, Ambrose was running in the top five of the Richmond 400. While racing Casey Mears mid-way into the race, Ambrose was bumped wide by Mears that lost Ambrose multiple positions. The two drivers confronted each other post race, which saw Ambrose land a punch into Mears' face after Mears was seen pushing Ambrose.^[35] Ambrose was fined $25,000 and Mears $15,000 for the altercation. Both drivers were placed on probation for one month.^[36] Despite the feud, both Casey and Marcos said they remain buddies and will "have a beer together" with Ambrose promising to buy.

Ambrose finished 10th at Daytona for a top-ten finish while his teammate Aric Almirola won the race when rain had shortened the event.

Ambrose returned to the Nationwide Series at Watkins Glen in the No. 09.^[37] Ambrose dominated the race and won his 5th Nationwide victory holding off Kyle Busch in a performance reminiscent of 2009. The next day Ambrose started second and after leading some laps, came up short after a side-by-side battle with former teammate A. J. Allmendinger who beat Ambrose by 1.5 seconds after accelerating away from Ambrose on the final lap. Ambrose's crew chief Drew Blickensderfer protested the finish by saying that Allmendinger jumped the restart, but NASCAR officials and Ambrose both denied this, Ambrose saying "The restart had no influence on the outcome. We just raced and he won."

Ambrose missed the Chase for the Sprint Cup and on 11 September 2014 said he did not expect to be back with Richard Petty Motorsports in 2015. This was soon after sponsor Stanley-DEWALT pulled out of RPM to join Carl Edwards' car at Joe Gibbs Racing but it is unknown if Ambrose's decision to depart had anything to do with Stanley-DEWALT pulling out their sponsorship of the 9 team. Not long after it was announced that Ambrose would be returning to Australia after the 2014 NASCAR season ends for what Ambrose and Petty described as "personal reasons."

In September 2014, Ambrose confirmed he would leave RPM and NASCAR at the end of the 2014 season with a purpose to return to Australia. Ambrose stated that it was for both personal reasons for his children and because he had accepted an offer to join DJR Team Penske, co-owned by NASCAR owner Roger Penske.

When asked about his departure from NASCAR Ambrose stated: "I think I've accomplished all I can accomplish in NASCAR. When I came it was clear all I could do was win races and not have any chance at a championship. I've enjoyed my time here and I will miss my friends and the other drivers very much but this move is done mostly to help my children get raised in our native country and I feel like I want to start a new chapter in my life. I'm glad to leave with multiple wins in NASCAR and having raced for the King."

In his final NASCAR race, the 2014 Ford EcoBoost 400, Ambrose qualified 17th. He struggled with a poor-handling car, and hit the wall on lap 195, but managed to finish 27th and on the lead lap.^[38]

Career summary

International V8 Supercars Championship

¹ Wildcard entry ineligible for championship points

Complete Bathurst 1000 results

Year	Team	Car	Co-driver	Position	Laps
2001	Stone Brothers Racing	Ford Falcon AU	Wayne Wakefield	DNF	42
2002	Stone Brothers Racing	Ford Falcon AU	Paul Weel	21st	154
2003	Stone Brothers Racing	Ford Falcon BA	Russell Ingall	6th	161
2004	Stone Brothers Racing	Ford Falcon BA	Greg Ritter	4th	161
2005	Stone Brothers Racing	Ford Falcon BA	Warren Luff	DNF	144
2015	DJR Team Penske	Ford Falcon FG X	Scott Pye	DNF	137

NASCAR

(key) (Bold – Pole position awarded by qualifying time. Italics – Pole position earned by points standings or practice time. * – Most laps led.)

24 Hours of Daytona

(key)

24 Hours of Daytona results
Year	Class	Team	Car	Co-drivers	Laps	Position	Class pos.
2005	GT	Aussie Assault	Porsche GT3 Cup	Paul Morris Craig Baird John Teulan	271	53 DNF	28 DNF
2013	DP	Michael Shank Racing	Ford Riley DP	A. J. Allmendinger Oswaldo Negri Jr. John Pew Justin Wilson	709	3	3