Petrol money - or gas money, as younger Kiwis tend to call it - has often been a sore point for the Great Kiwi Road Trip, or just when buzzing around town.
And with the cost of gasoline spiking at this point in the pandemic, it's something you need to keep tabs on more than ever.
Enter Roadtrip, an app that helps you calculate the petrol cost of any given route in NZ.
You enter your start point, your destination, and your licence plate number, then Roadtrip tells you the petrol cost - complete with an option for splitting the bill.
Your plate number is Roadtrip's secret sauce.
"Originally, Roadtrip required users to enter their car's fuel efficiency in kilometres per litre," says Emory Fierlinger, who created the app with fellow student Ben Robertson.
"However, I soon realised something while user testing: Nobody in their right mind knows their car's fuel efficiency. Literally no one I talked to.
"So it was back to the drawing board, I had to come up with something that was easy for people to enter, but accurate enough that it wouldn't show misinformation."
He struck on your number plate. You enter your rego, then Roadtrip syncs with an open government database to extract the make, model and year of your car and its KM/litre fuel efficiency.
The price of petrol factored in is a weekly average. Roadtrip's makers are looking to add regional pricing.
Roadtrip will also calculate the cost of recharging your EV on any different route.
Technology runs in Fierlinger's blood. His father, Philip Fierlinger, worked with legendary Apple foundation employees Bill Atkinson and Susan Kare, before he and his wife decided New Zealand would be a better place to raise children. They decamped from San Francisco to Auckland in 2001, with a pre-school Emory in tow.
Philip Fierlinger was part of the crew who co-founded Xero in 2006. Today he runs restaurant, cafe and bar supplies start-up Upstock with another Xero alumnus, Duncan Ritchie. Upstock is also where Emory Fierlinger and Robertson have their day jobs (both graduated this year, Fierlinger from Massey, Robertson from Victoria).
Thanks to a Roadtrip prototype, Emory Fierlinger was an Apple WWDC (Worldwide Developer Conference) Student Scholarship winner in 2019 and he attended the annual event in California - not knowing at then that it would be the last real-life Apple event for some time.
He and Roberson used Apple Mapkit and features like the iPhone's haptics to develop the first release version of Roadtrip, which only hit the App Store a couple of months ago (it's also on Android). Now, with travel restrictions finally starting to ease under the traffic light system, their apps' time has come (for now, its licence plate trick will only work in NZ).
"Our goal was to get 100 downloads by the end of the year – we're already at over 2000 and we're growing really quickly," Fierlinger says.
Usage has grown from friends splitting road trip petrol bills to delivery drivers who want a free and easy way to calculate the most cost-efficient routes to businesses doing calculations for tax purposes.
"Ultimately, we would love to help encourage consumers into a more sustainable future with electric cars. We're working on helping show the difference in cost if you were driving an electric vehicle – how much money you could save on each trip. That feature will launch this month," Fierlinger says.
An update that shows the carbon emissions of your trip will launch in a couple of weeks and Te Reo support is on the way.
For now, Roadtrip is a passion project - especially with its charging cost feature for EVs, which he hopes will chip into efforts to drive up electric vehicle adoption.
But Fierlinger has already been in talks with a large energy company about a possible partnership.
Like his dad, he has big plans.