Paul Dumbrell insists that his position as Jamie Whincup’s co-driver is not guaranteed for 2017, labelling his own performance this season ‘unacceptable’.

The 34-year-old was one of the quickest co-drivers at Sandown, Bathurst and the Gold Coast, setting up victory for the #88 Holden with his drive in Sunday’s Pirtek Enduro Cup finale.

Dumbrell, however, rates his overall performance as a ‘D’ grade effort after a mistake in the driver change process at Sandown resulted in a drive-through penalty.

In the below Q&A, Dumbrell tells Speedcafe.com’s Stefan Bartholomaeus about his mistake, another heartbreaking Bathurst defeat and whether he’ll be back again in 2017.

SPEEDCAFE: PD, what does it mean to you to win another one of these races (first win since Gold Coast, 2014)?

Jamie gets the spotlight no matter what, but you’ve been on a heck of a journey over the last 24 months.

PAUL DUMBRELL: The last two years have been really interesting for us.

We set out as a partnership five years ago to really say ‘we’d love to win every race, but what we’re aiming to do is to be competitive in every race’.

We’ve had three poles this year (in the Enduro Cup), so clearly we’re quick at all the tracks, but circumstances have meant that we haven’t won.

Being really honest, I threw Jamie’s championship lead away at Sandown.

Whether we would have won the race or not, the drive-through cost us dearly.

That’s not good enough for a guy who has been doing it for 16 or 17 years. It’s unacceptable.

I’ll look back at the campaign and say it’s been great for the team to secure the Teams’ Championship and the Pirtek Enduro Cup.

But I look at my own performance and say it was below par.

We had good races at Bathurst and the Gold Coast but you are judged on your worst performance and Sandown was pretty bad.

SPEEDCAFE: Sandown is one thing, but Bathurst is the big one.

You’ve sat there for four years and seen the win slip away in the final stint. That must be difficult to deal with?

DUMBRELL: We are lucky to be in a team that gave us the opportunity to win the race back in 2012.

The last three years have been really, really tough, but our whole philosophy is that we go hard.

Has it worked for us? Yeah, we’ve won each of the races (Sandown, Bathurst and the Gold Coast).

Has it worked against us? Maybe. The records will probably dictate that.

But the disappointing thing over the last few weeks has been the reaction from a wide variety of fans and Supercars themselves.

Fundamentally they’re challenging Jamie’s integrity.

He’s a six-time champion and a four-time Bathurst winner with over 100 race wins to his name.

People on social media are having a big crack. That’s part of the sport, but it’s disappointing that someone of his stature isn’t getting more respect.

You don’t win 100 races by rolling over and letting people through.

Scotty (McLaughlin) wasn’t going to let him through and Jamie went for a move that I strongly believe was on.

What Scotty did on Sunday (at the Gold Coast in his late-race pass on Mark Winterbottom) was equal if not worse of a move than what Jamie did at Bathurst.

It’s interesting. But we can’t dwell on it. Bathurst is run and won and for us, it’s one that got away.

SPEEDCAFE: Jamie brushed off the latest disappointment and the criticism that followed by saying it didn’t impact him at all. Do you think that’s true?

DUMBRELL: Honestly, I don’t think it does for either of us.

I was disappointed, sure, but at the end of the day you’ve got to use heartbreak to motivate you to work harder and put yourself in a position next year where you don’t make those mistakes.

That’s why Sandown was so disappointing to me. The first half of the race with the changing weather conditions, it was one of the most challenging races I’ve ever done.

To come through all that and then make the mistake in the last 0.01 of a percent of my time in the car…

At the end of the day you can’t let what people think about you affect you.

I value Jamie’s opinion of my job, as well as what Roland (Dane, team owner) Dutto (Mark Dutton, team manager), (David) Cauchi (engineer) and those guys think.

We win and lose as a team and playing my role in that team is what matters to me.

QUESTION: So next year, are you going around again? It’s obviously a big commitment for you having to run the Dunlop Series in order to keep sharp for this.

DUMBRELL: Next year I wouldn’t run the old spec car (in the Dunlop Series), so it’s not as straight forward as what it probably has been for the last couple of years.

We spoke about it in the lead-up to the Gold Coast race after the appeal was done and dusted, but we’ll work through it in the next month or so.

I’d absolutely like to do it, but if I can’t race another car I wouldn’t put my hand up for it, regardless of what the team thinks.

I learnt in 2013 the impact it had on me not racing throughout the year.

Whether I’m driving or not, I’d share the same emotional joy seeing the team win.

QUESTION: Surely between yourself (a co-owner of Triple Eight), RD and Eggleston (Motorsport, Dunlop Series team), you’ll get something done?

DUMBRELL: It’s not as simple with the COTF cars because there’s just not enough of them around.

Egglestons are a commercial business and it’s worked for the last three years because we’ve run three cars.

Two (Eggleston having bought two COTF T8 cars) is a different thing and it would be pretty tough for it to happen with them running two cars.

QUESTION: Your business world has changed a fair bit in the last year. Has that taken any load off of you away from the track?

DUMBRELL: I changed roles within the business, moving into the COO position of the overall Bapcor Group.

I’ve got a fairly big range of responsibilities now which is completely different to what I’ve done over the last seven years.

But that’s taking up more time rather than less. The last two years hadn’t been too bad, it was quite settled down.

I’ve got a young boy now who is seven months old and I’m getting married at the end of the year.

So full-time for nine years and five years with Jamie, I couldn’t ask for any more with the stories and laughter we’ve had.

We’ve had the highest of highs and lowest of lows. The lows hurt more, but the highs have made it worth it.

You’ve got to be a realist about it and the only true judge of your own performance is yourself.

SPEEDCAFE: So with your self-assessment hat on, what grade do you award Paul Dumbrell for the 2016 Pirtek Enduro Cup?

DUMBRELL: A ‘D’. We had an ok run at Bathurst, but I was given the car with a good lead and a few others fell out.

I didn’t make any mistakes… but I did make a few in the Dunlop Series.

We won the race, but that would have been closer to an E that performance.

I nearly binned the car twice leading by five or 10 seconds. That type of stuff is unacceptable.

Maybe I’m a harsh marker, but Alex (Premat) and I aren’t employed to be average co-drivers.

We’re employed to be as close to the main drivers as we can be.