See all Motoring Advice The Irish government is considering introducing a new form of taxation that penalises vehicles according to their weight.
The Tax Strategy Group (TSG), an expert advisory panel which reports to the Department of Finance, has suggested that a €1.5 billion annual tax funding gap - which has opened up as more and more people move to electric vehicles (EVs) - needs to be plugged.
The €1.5bn deficit has come about because of losses from existing motoring tax bases, such as annual motor tax, VAT and petrol and diesel excise receipts.
With the electrification of Ireland’s fleet only set to grow from hereon in, the TSG is therefore advising in its annual reports ahead of Budget 2026 - due to be announced in October - that to counteract the erosion of these existing, historic tax bases, the government should look to move to a weight-based system of taxation instead.
This is because data shows that, between 2001 and 2022, the average weight of passenger vehicles in Ireland increased by around 28 per cent, primarily as our tastes have shifted towards buying larger and more luxuriant SUVs instead of family hatchbacks and similar.
It also follows on from similar weight-based taxation systems, which have either already been put into place by other countries in the EU, such as France, or which are being proposed (in the Netherlands and Estonia, for instance).
While the plans for Ireland are by no means finalised at this stage, it’s worth a look at the potential issues raised by implementing a taxation system based on vehicle weight.
Why tax vehicles on weight? Why is weight a problem for cars?
As we demand more and more technology, and more and more refinement and safety, from our modern-era cars, they inevitably get bigger – and heavier.
In moderation, this isn’t such a bad thing. But if an entire country’s fleet of vehicles switches from being smaller, lighter and more fuel-efficient cars to bigger, heavier and thirstier ones, several impacts are felt as a result.
From a safety perspective, heavier vehicles require more stopping distance. A car which weighs 2,500kg rather than 1,500kg will need more space to stop from a given speed unless manufacturers significantly uprate the brakes to cope. This results in greater expense, which is ultimately passed onto the consumer.
Heavier cars are also harder on wear-and-tear items, such as tyres, suspensions bushes and brake pads and discs. That theoretical 2.5-tonne car mentioned above will, if driven in the same manner as the 1.5-tonne car over an equivalent distance, require replacement of all of these parts sooner than the lighter vehicle would, again placing more financial strain on the end user.
Furthermore, the heavier a vehicle, the less fuel-efficient it is – thus requiring greater use of existing resources and also more expenditure from owners. This doesn’t just apply for petrol and diesel cars, which obviously use more fossil fuel per kilometre if they’re heavier, but EVs too; the longer-range models with bigger batteries typically have less impressive electrical efficiency ratings, in terms of kilowatt-hours used per 100km travelled, than lighter, shorter-range EVs.
There is also an argument which says heavy vehicles place greater stress on our road network. While one driver switching from a 1.5-tonne car to a 2.5-tonne machine wouldn’t have an obvious, immediate impact, when thousands of us are changing from smaller hatchbacks to bigger SUVs the cumulative effect starts to take its toll. Potholes in the road will appear more frequently, as will ruts in the tarmac where the traffic is most often flowing; these defects will then require more regular repair work, at added expense to the taxpayer and with the inconvenience of time-consuming roadworks being in place while the repairs are carried out.
The aforementioned advanced tyre and brake wear on a heavier car also leads to a form of pollution. While most people focus on the emissions put out by the exhaust pipes on cars with internal combustion engines as the main cause of pollution, there are also particles given off by all vehicles as their tyres and brake pads slowly wear down during prolonged usage. In heavier vehicles, more of these particles are emitted at a faster rate than with lighter vehicles.
One of the problems here is that the proposed taxation system is looking to penalise our consumer shift towards SUVs powered by petrol, diesel and hybrid systems that still use a combustion engine in some form, but some of the heaviest cars on the roads today are EVs. This is down to the fact that the battery pack is the weightiest item in any EV and battery technology is not yet advanced enough to give us the driving range we want from EVs but provided by smaller, lighter batteries.
Yet should EVs be excluded from the weight taxation system? After all, it is a move towards zero-emission vehicles that has opened up the annual €1.5bn funding gap the TSG has identified in the first place.
How does the French system work?
The French system is highly punitive on any vehicles which weigh more than 1,599kg – but it specifically exempts EVs and also any cars which run on hydrogen fuel.
It does not, however, overlook hybrid or plug-in hybrid vehicles, which typically tend to be heavy. Most plug-in hybrid SUVs these days are around 2,000kg or more.
The French weight taxation only applies to brand-new cars and is paid for the year of first registration of the vehicle. So, it does not apply after a car has left a showroom, or for anything bought on the second-hand market.
That said, it is highly punitive on heavier cars. For every single kilogram in excess of 1,599kg, there is a sliding scale of tariffs that must be paid. For the 200kg above 1,599kg (i.e., for cars weighing 1,600-1,799kg), it is €10/kg. For 1,800-1,899kg, it rises to €15/kg. From 1,900-1,999kg, the rate is €20/kg and then it becomes €25/kg for 2,000-2,099kg. For any vehicle weighing 2,100kg and above, every single kilo incurs a €30 penalty.
As an example, something which weighs 1,950kg – roughly speaking, the current Audi S5 Avant without a driver onboard – would incur €2,000 for its 200kg from 1,600-1,799kg, another €1,500 for the 100kg from 1,800-1,899kg, and a further €1,020 for the 51kg from 1,900-1,950kg, resulting in an overall weight-tax burden of €4,520.
But were EVs to be subject to the weight tax in Ireland, then they would be even more heftily penalised if we were to adopt the same system as the French but without its exemptions. A Skoda Enyaq RS, for instance, weighs 2,377kg, which would result in a huge €16,310 bill as a result of its mass.
The French system also only has a cap at a colossal €70,000, so there’s every chance EVs could be heavily punished if the Irish government decides not to exempt them to prevent the TSG’s identified €1.5bn tax losses through other channels – but that would then, in turn, dissuade buyers from the electrification of our national fleet, so it’s a Catch-22 situation.
Will this weight tax apply retrospectively to existing cars?
No, it shouldn’t do – it should follow the French path and only be applied to brand-new cars. This means that existing heavy vehicles on our roads, like pickups and SUVs, would not be subject to the weight tax, although they would still be under our tough CO2 laws which tend to prohibit the most tailpipe-polluting vehicles via means of higher annual taxation.