Jamie Whincup is enduring his worst run in V8 Supercars in eight years, but the five-time title winner has vowed to keep fighting.

Whincup hasn’t stood on the podium in any of the past six championship races – something not seen since 2006, when he jumped from Holden to Ford to join Craig Lowndes at Triple Eight Race Engineering.

He came close with two fourth-placings in Saturday’s sprint races at Auckland’s Pukekohe track – an improvement on his 24th on Friday because of power steering issues – but was kept at bay by race winners Mark Winterbottom and Shane van Gisbergen.

“We just weren’t quick enough for a podium but we put in our best effort,” the 31-year-old said.

“It’s a fine line – I fought as hard as I could but if you go too far you end up in the gravel trap.

“At the end of the day you’ve got to finish races so you have to pick your battles. (Yesterday) the top pack were quick and I decided that I couldn’t quite hold them off so I’ll look to get them another day.”

Whincup cemented himself as one of the category’s greats last year, becoming just the fourth driver to ever win five championships.

But his tilt for a record sixth crown has taken a significant hit.

Despite being the only driver to win three races this year, bad luck and a string of mechanical issues have cost him dearly – particularly last round at Winton.

After 12 races, he sits fifth on the overall drivers’ standings – 94 points behind leader and long-time Ford rival Winterbottom.

But with just 134 points separating the top six, things could change dramatically on Sunday with 150 points up for grabs in the weekend’s final 200km race.

“We’ve raced three races to effectively score what we can score (today), so (today’s) the key day,” said Winterbottom, who leads Craig Lowndes by two points following his win and second-placing in Saturday’s two 100km sprints.

Qualifying begins at 11am (AEST) before the race at 1.25pm (AEST).