Tony Stewart hopes Fontana race can get his season on track

Tony Stewart is known for sometimes starting sluggishly when the NASCAR season opens and then picking up steam as the weather gets warmer.

This year is no exception — at least as far as his slow start is concerned.

Stewart is 24th in the title standings as the three-time Sprint Cup Series champion arrives for the race Sunday at Auto Club Speedway in Fontana.

But Stewart is the defending winner of the Auto Club 400; last year he did get off to a good early start. And another strong showing on the two-mile Fontana oval could help the veteran driver get back into championship contention.

Stewart also won at Fontana in a fall race in 2010 and overall he has 12 top-10 finishes in 21 starts at Auto Club Speedway.

NASCAR introduced a new car this year, dubbed the Gen-6, and Stewart along with everyone else is still trying to find the car’s optimum setup.

“This is a car that doesn’t come with an instruction manual,” Stewart said in notes released by the Stewart-Haas Racing team that prepares his No. 14 Chevrolet. “It’s a constant work in progress.

“What’s been understated is how good this car has been right out of the box. It’s a nice car. It’s a well-balanced car. For the few races we’ve had, I think it’s been an overwhelming success.”

Stewart, nicknamed “Smoke,” got off to a poor start at this year’s season-opening Daytona 500 when he was involved in an early crash, and he finished 41st in the 43-car field.

After an eighth-place finish in Phoenix and an 11th in Las Vegas, Stewart ran into more bad luck last weekend in Bristol, Tenn., when his left-rear tire blew on the ninth lap, sending his car into the wall. After getting repairs, he finished 31st.

Stewart, 41, co-owns his team with Gene Haas, founder of the machine-tool maker Haas Automation based in Oxnard.

The team’s two other drivers also are struggling early this season. Ryan Newman is 23rd in the point standings and Danica Patrick, driving her first full season in the Cup series, is 28th.

Hornish leads Nationwide Series

Sam Hornish Jr. leads the title standings in NASCAR’s second-level Nationwide Series ahead of its race Saturday at Auto Club Speedway, the Royal Purple 300.

Hornish, an Indianapolis 500 winner who migrated to NASCAR stock-car racing a few years ago, won the Nationwide race in Las Vegas two weeks ago and has finished in the top 10 in all four of the series’ races this year.

“The way this team has been performing so far this season ... I feel like we have a legitimate shot at this one,” Hornish said of the Fontana race.

Highly touted Nationwide rookie Kyle Larson also will be making his debut at Auto Club Speedway. The 20-year-old Californian nearly won last weekend’s race in Bristol but finished just behind winner Kyle Busch.

james.peltz@latimes.com