"There isn't a lot of difference between an 1800 [CC engine] and a 1300.
"Obviously there is a difference, but if you put it on a full tank of gas, you're measuring it in cupfuls rather than in bucketfuls."
Modern cars did not have to work as hard as older models and were subsequently more fuel efficient, he said.
Mr Friis said the oldest car he sold last year was a 1989 Toyota Carona which had only 70,000km on the clock. "It was one out of the box." The average car he sold was a 2003/04 model.
Nationally, 782,575 used cars changed hands last year - up 23 per cent year-on-year. Most (451,218) were through private sales such as Trade Me.
MTA spokesperson Ian Stronach said the number of new cars imported (100,795) had been steadily growing and now outstripped used imports (81,827).
The Toyota Corolla, Suzuki Swift and Mazda 3 were the top used imports last year.
Unlike the early 2000s when New Zealand was importing two used imports for every new car, used imports had dropped off - because of a combination of tougher exhaust emission standards and scores of used cars already in the domestic market, he said.
"We were adding big numbers and the fleet grew rapidly in that period.
"There's almost no [used] trucks being imported [now] because they don't meet the standard, or buses, and they used to be big - small trucks particularly."
Although the number of imported used cars were well short of mid-2000s levels, they remained a strong part of the local market, Mr Stronach said.
"The reason for that is they get to a price point where you go to trade it in or you go to sell it on Trade Me and it's worth a grand or less, the dealer doesn't want it, no one wants it on Trade Me. But this car still works and you can still get a warrant reasonably easy, so a lot of New Zealanders are retaining quite old cars."
There were 2.8 million to 2.9 million licensed light vehicles in the country with an average age of 13 years - "ancient by first world standards", Mr Stronach said.
Buyers had been favouring newer, more fuel efficient cars, with a preference for four-cylinder vehicles, he said.
Trade Me spokesman Jeff Hunkin said about 140,000 cars were sold on the site last year with Toyota, Nissan and Mitsubishi the most popular makes.
Rotorua region used car sales:
All of 2012
1697 cars sold from the public to traders (22 per cent increase)
2982 cars sold from traders to the public (21 per cent increase)
7970 cars sold privately between members of the public (21 per cent increase)
21 per cent year on year increase
National used car sales:
All of 2012
141,766 cars sold from the public to traders (26 per cent increase)
189,591 cars sold from traders to the public (29 per cent increase)
451,218 cars sold privately between members of the public (20 per cent increase)
23 per cent year on year increase
- Source: MTA