The island has taken delivery of its first hybrid buses - as part of the government’s drive to go carbon neutral by 2050.
A total of 16 new buses recently arrived as part of scheduled replacement programme.
The total investment included in this year’s Budget as part of the rolling capital replacement programme is about £3.7m.
The ongoing modernisation of the fleet is designed to significantly improve vehicle emissions.
It also enables used vehicles to be sold on while they are still in good condition.
Six Mercedes Citaro single deck low emission hybrid vehicles have been acquired.
These hybrids combine a conventional internal combustion engine with an electric propulsion system.
Public transport bosses say the aim is to increase sustainable forms of public transport.
But they have no plans to introduce all-electric buses, insisting there are no zero emissions vehicles currently available that have the power and range required.
The arrival of 10 double deck StreetDecks will see them replace 10 Volvo vehicles, stepping up emissions standards from Euro 5 to Euro 6.
The Manx government has pledged to ban the sale of new petrol and diesel cars by 2040 as part of its target to become net-zero in carbon emissions by 2050.Some towns in the UK are already using all-electric buses on some routes.
In Guildford, Surrey, for example, the Glide park and ride route has been operating with a fleet of zero-emission single deckers since January last year.
The fleet of Enviro200EVs are built by Alexander Dennis, which is based in Surrey’s county town.
Bus Vannin said the Enviro200EVs do not have the range required for services on the island.
There is an electric Citaro but Bus Vannin said the current version will not operate to the required duty cycles in the Isle of Man.
Isle of Man Transport insists the size of the fleet had fallen from 90 to 68 and buying new buses each year saves on maintenance costs.
Vehicles, which have an operational life of eight-11 years, are replaced as part of a rolling £25.2m programme.
A Freedom of Information request in July 2018 revealed that Bus Vannin had spent more than £6.2m on buying new buses since 2016.
By that point Bus Vannin had a fleet of 52 Mercedes buses comprising 33 Citaro single deckers, which cost between £134,490 and £169,100 each, and 19 Sprinter minibuses costing between £56,960 and £86,975 each.
In 2018, the DoI declined an FoI request to detail how much it had spent buying new buses, insisting this was commercially sensitive.
But the DoI was forced to publish the costs following a ruling from the Information Commissioner.
All the new buses come fitted with WiFi and USB charging points.