The2018 Auto Club 400 was aMonster Energy NASCAR Cup Seriesrace that was held on March 18, 2018, atAuto Club Speedway inFontana, California. Contested over 200 laps on the two-mile (3.2 km) D-shaped oval, it was the fifth race of the2018 Monster Energy NASCAR Cup Series season.

2018 Auto Club 400

Race details[1][2][3][4][5][6][7][8][9][10]
Race 5 of 36 in the2018 Monster Energy NASCAR Cup Series
2018 Auto Club 400 program cover
Date	March 18, 2018 (2018-03-18)
Location	Auto Club Speedway inFontana, California
Course	Permanent racing facility
Course length	2 miles (3.22 km)
Distance	200 laps, 400 mi (640 km)
Average speed	147.526 miles per hour (237.420 km/h)
Pole position
Driver	Martin Truex Jr.	Furniture Row Racing
Time	38.592
Most laps led
Driver	Martin Truex Jr.	Furniture Row Racing
Laps	125
Winner
No. 78	Martin Truex Jr.	Furniture Row Racing
Television in the United States
Network	Fox
Announcers	Mike Joy,Jeff Gordon andDarrell Waltrip
Nielsen ratings	2.4 (Overnight)[11]
Radio in the United States
Radio	MRN
Booth announcers	Joe Moore, Jeff Striegle andRusty Wallace
Turn announcers	Dan Hubbard (1 & 2) and Kurt Becker (3 & 4)

Auto Club Speedway (previously California Speedway) was a two-mile (3.2 km), low-banked, D-shaped oval superspeedway in Fontana, California which hosted NASCAR racing annually from 1997 to 2023. It was also used for open wheel racing events. The racetrack was located near the former locations of Ontario Motor Speedway and Riverside International Raceway. The track was owned and operated by International Speedway Corporation and was the only track owned by ISC to have its naming rights sold. The speedway was served by the nearby Interstate 10 and Interstate 15 freeways as well as a Metrolink station located behind the backstretch.

Kevin Harvick was the fastest in the first practice session with a time of 38.082 seconds and a speed of 189.066 mph (304.272 km/h).^[12]

Martin Truex Jr. scored the pole for the race with a time of 38.592 and a speed of 186.567 mph (300.250 km/h).^[13]

Kevin Harvick was the fastest in the second practice session with a time of 38.694 seconds and a speed of 186.075 mph (299.459 km/h).^[14]

Kyle Busch was the fastest in the final practice session with a time of 38.779 seconds and a speed of 185.668 mph (298.804 km/h).^[15]

Martin Truex Jr. led the field to the green flag at 3:46 p.m. Winner of three consecutive Cup races,Kevin Harvick was shooting for a higher spot in history with a fourth Sunday, but that march ended early in the race when he collided withKyle Larson on the backstretch, bringing out the first caution on lap 39. They were running side by side when Harvick appeared to move down the track and into the side of Larson’s car. The impact sent Harvick’s car into the outside wall, causing heavy damage.

The race restarted on lap 43.

Martin Truex Jr., master of stage wins last season, scored his first of the new year, leadingKyle Busch by 3.5 seconds. Also in the top 10 wereJoey Logano,Brad Keselowski,Jimmie Johnson,Kyle Larson,Kurt Busch,Erik Jones,Clint Bowyer andDenny Hamlin. The second caution of the race flew on lap 62 for the conclusion of the first stage.

The race restarted on lap 67.

Trevor Bayne slapped the outside wall after slight contact withRyan Newman. The incident produced the race’s third caution of the race, which was on lap 109. Bayne called his meeting with the wall one of the hardest of his career.

The race restarted on lap 114.

Truex scored again at the end of stage two, leadingBrad Keselowski by 1.8 seconds. Following wereKyle Busch,Denny Hamlin,Erik Jones,Joey Logano,Jimmie Johnson,Kyle Larson,Clint Bowyer andWilliam Byron. The fourth caution of the race flew on lap 122 for conclusion of stage 2.

The race restarted on lap 127.

The fifth caution of the race flew on lap 130 whenDavid Ragan spun out in turn 2, soTy Dillon won the free pass under caution.

The race restarted on lap 132.

The closing portion of the race featured a battle for the lead matchingMartin Truex Jr.,Kyle Busch andKyle Larson. With 18 laps to go, Truex had a five-second lead over Busch and Larson, who were fighting for second.

Martin Truex Jr., last year’s Cup champion, returned to victory lane — a place he visited eight times in 2017 — and, at the same time, droppedKevin Harvick’s name from NASCAR’s marquee. At least temporarily.^[16]

“This is a reassurance that what we’re doing is working,” Truex said. “It just feels good to win. I don't really worry about who's winning or who else is fast. Obviously, the 4 (Harvick) has been quick and they have a great team. But, as we’ve seen today, we can put together a run like that, as well.

“It feels good to be able to find that speed.”

Stage 1Laps: 60

Stage 2Laps: 60

Stage 3Laps: 80

• Lead changes: 7 among different drivers
• Cautions/Laps: 5 for 21
• Red flags: 0
• Time of race: 2 hours, 42 minutes and 41 seconds
• Average speed: 147.526 miles per hour (237.420 km/h)

The race was the 18th raceFox Sports covered at theAuto Club Speedway.Mike Joy, three-time Auto Club winnerJeff Gordon andDarrell Waltrip had call in the booth for the race.Jamie Little,Vince Welch andMatt Yocum handled the pit road duties for the television side.

MRN had the radio call for the race which was also simulcasted onSirius XMNASCAR Radio. Joe Moore, Jeff Striegle and 2001 race winnerRusty Wallace called the race from the booth when the field was racing down the front stretch. Dan Hubbard called race from a billboard outside turn 2 when the field was racing through turns 1 and 2. Kurt Becker called the race from a billboard outside turn 3 when the field was racing through turns 3 and 4. Alex Hayden, Winston Kelley and Steve Post worked pit road for MRN.