"But if I show The Hulk, it just means I'm not fake. I don't like to cover things up to maintain a persona, that's just not me."
New Zealanders cottoned-on to his spade-a-spade, up-front attitude pretty quick.
Murphy is a favourite sporting son - he won the Bathurst 1000 four times and is one of the best-known V8 Supercar drivers - and during this interview in a bustling Auckland cafe, people interrupt to shake his hand, quietly tell him in a bloke-to-bloke way how much they admire him and what he's done.
His famous 2005 crash, then an out-on-the-track dust-up with fellow Bathurst competitor Marcos Ambrose, is a motorsport YouTube favourite. He still gets asked about it at every speaking engagement.
But suggest to Murphy that he's a legend then prepare for a rising of the hackles.
"I don't like that word. You've got to do some pretty incredible things to be labelled a legend or a sporting hero. Sportspeople shouldn't be labelled heroes. We just do what we love doing and are bloody fortunate to be doing so."
Nevertheless, this much-admired racing driver has had a Big Ben pie and a Burger King burger named after him.
And now he has his own motorsport TV show, #Skyspeed. It debuts this Thursday on Sky Sport 3 at 7.30pm and is touted as the fastest 30 minutes on television.
The weekly show will be filmed at various motorsport hotspots and include the petrolhead delights of F1, Nascar, IndyCars, V8 Supercars and Superbikes, to name a few.
Co-host and Sky stalwart Stephen McIvor can vouch for the speed aspect of the show. "We were shooting the promo in the car at Hampton Downs and Murph cheekily pointed to the speedo, which was at 236km/h."
McIvor was fine with that. "It was when we went right up the bumper of the promo car shooting in front of us that I just about wet my pants. But Jeez, it demonstrated exactly how much control Murph had over that vehicle."
Yep, Murphy takes control. As a young driver across the Tasman in the V8 SuperCar Championship he had the foresight and good entrepreneurial advice from a "couple of Aussie blokes who I've always trusted" to help guide his career on the racetrack. He became a pin-up boy for Holden.
"I could see things were starting to steamroll, after winning Bathurst and I knew it was important for me to grow my profile. It was a bit different in the motorsport industry then. There was money, we were making ads with big marketing budgets and it really was awesome."
He laughs at some of the kids these days, who approach him and say, "my Dad's a fan of yours, but my Mum loves you". Does he mind that?
"It's funny," he says wryly, indicating that he doesn't mind in the slightest. "But those mums are probably my age now and they probably remember me because of the profile back then."
Murphy severed ties with the fulltime V8 SuperCar Championship at the end of 2012. He didn't want to give up the drive and admits he went through a stage of being bitter and twisted. "I wasn't happy. The team was struggling and proposing to change manufacturers and I didn't want to do that." He could have hung up the keys for good. "I was scared, it was a big change. I was wondering how I was going to pay the bills but
I was focused. I secured a drive with an enduro team, [he co-drives again at Bathurst this year]. I was always going to come back and see what New
Zealand was offering."
That was the V8 SuperTourer Championship. He won the title last year and is currently way ahead on the table of this year's event with eight wins from nine races. There's one more V8 event over the long Anzac Weekend, then it falls to some serious winter downtime, snowboarding with the kids at Ruapehu and enjoying the new bach at nearby Taupo.
He is also eyeing up property in his home digs of Havelock North. Born there and schooled there, it's now where he wants his three children to grow up.
"I struggle with the word permanent," says Murphy. "We've been back two months and we're renting at the moment, so we really want to find the perfect spot."
The somewhat cramped inner-city suburbs of Melbourne have been home to Murphy, his wife of 11 years Monique and children Ronan, 12, Cormac, 10, and Neve, 6, for years.
He's not afraid to admit that their third child was a little unplanned.
"Complete and utter laziness on my behalf. I was shocked," he says, shaking his head, "But Neve has turned out to be the biggest amount of fate that will ever guide me. She is hilarious, crazy and fantastic entertainment for us."
There is big Irish ancestry in the Murphy clan - hence the children's names. Monique, a Wellingtonian, is also of Irish descent. "Maybe the next cuisine they name after me will be a spud," Murphy laughs.
It was Monique who, during the clean-out and box-packing from Melbourne, discovered Murphy's school reports. "I certainly won't be showing those to my children," he says shrinking down in the chair.
"They all say the same thing, year after year, 'Greg would achieve a lot more if he wasn't continuously acting the class clown'. I wouldn't say I was the most popular kid at school but I managed to make some lifelong friends."
His eldest son Ronan is already a regular on the local Hawke's Bay karting scene - right where Murphy started his career with his father Kevin by his side. "He's obsessed, to my dismay, but hey, what did I think was going to happen?
"I was late getting started in the big cars. I was 19.
I won a scholarship at Manfeild. Had it not been for that, I might never have had a career in racing.
"Dad and I just thought it was going to be karting. It wasn't even worth talking about anything bigger because it was like a dream that was never going to happen. But he knew that was what I wanted."
And so the dream came true. Murphy can't yet put a date on when he'll stop racing. "I still love to compete."
He's yet to see Rush, Ron Howard's movie detailing the fierce Formula One rivalry between Austrian Niki Lauda and playboy Brit, James Hunt.
"I refuse to watch that one on a plane but what a great story. The passion, the rivalry and two people with the very same goal, yet doing it completely differently."
Murphy is no stranger to great rivalry himself. Just ask what happens when he pulls up next to a Ford at the traffic lights, behind the wheel of his incognito white Holden.
"It's funny. Some will jokingly give you the fingers; others squirm in their seats and look the other way or it's just a general hoo-ha and shout out the window."
He is new to social media. Follow him on Twitter if you like, @gmracing51, but don't expect too much interaction. "Twitter. . ." ponders Murphy. "As an information tool it's brilliant but I don't want to get into reacting to the nutbags. It would wind me up."
Murphy continues to get wound up about road safety in New Zealand. He is the face of the Motor Trade Association's in-school safety programme and he wants new drivers to have professional driver training and the skills to cope with New Zealand's unique roading conditions.
"The training side of things is absolutely critical. I can guarantee that if people had the skills and training to start with, we would be in a much better situation, where a lot of these crashes that happen would have a chance of not even happening."
He has cautionary tales of his own, writing off his beloved first car, a Datsun 1200SSS.
"I got charged. I was 18. It's probably the least proud moment of my life. I injured my passenger and I was someone who knew how to drive. You think these things aren't going to happen to you and it's naive."
He uses this incident as a tool to resonate with young hearts and minds as far as road safety goes.
That model of Datsun is now back in Murphy's personal garage. "I literally haven't owned a car for years, but I'm starting to now. Mainly early-70s muscle cars."
Favourite car of all time? "Definitely the 69 Dodge Charger. I've got one. It's a project between me and a few very passionate men in Auckland."
But don't expect to see it painted in the flashy, loud Dukes of Hazzard colours. "Daisy Duke in the front seat maybe," he giggles, with a wink.
No denying this motorsport maestro has no intention of slowing down just yet.
Join Greg Murphy and co-host Stephen McIvor on #Skyspeed, this Thursday, 7.30pm, Sky Sport 3.
