The average age of Tasmanian vehicles was 12.9 years on January 31, the Australian Bureau of Statistics found.

That compared to 10.2 years nationally and 9.4 years in the ACT, which had the nation's youngest vehicle fleet.

The number of vehicles registered in Tasmania had increased by 2.6 per cent in a year.

Tasmania had 493,358 vehicles registered on January 31.

Of those, about one third - 164,939 - were manufactured in 2003 or earlier.

The state still had 16,438 vehicles using leaded petrol.

A further 343,704 vehicles used unleaded petrol, 130,629 used diesel and just 2587 used other fuel sources.

The figures also underlined Tasmania's love affair with vehicles and, perhaps, its decentralised nature.

The state had 931 vehicles people 1000 residents.

That was easily the highest rate of any state or territory and well ahead of the national rate of 777 vehicles per 1000 people.

The state had 338,229 registered passenger vehicles, 5021 campervans, 110,109 light commercials, 4053 light rigid trucks, 9510 heavy rigid trucks, 2057 articulated trucks, 941 non-freight carrying vehicles, 3008 buses and 20,430 motor cycles.

The ABS said Toyota remained Australia's most popular registered vehicle marque, with 2.9 million on the register.

Mazda and Hyundai continued to grow strongly and came in third and fifth respectively.

New registrations of Holdens (the second most common) and Fords (fourth) had continued to decline.

Registration of diesel vehicles had continued to grow.