How much will it cost me to run my plug-in hybrid car?

Mitsubishi has just released a white paper concerning the economic and ecological sustainability of plug-in hybrid electric vehicles (PHEVs) for typical consumers.

Incorporated in that white paper, ‘The Road to Net Zero Emissions’, is a section devoted to the controversial taxation costs of running a PHEV versus an internal combustion engine (ICE) car of similar specification and a battery-electric vehicle (BEV) equivalent.

The company has cited three typical PHEV owners: urban commuter (‘Driver A’), working parent (‘Driver B’) and fleet driver (‘Driver C’).

By running the car in EV mode more often, Driver A – the urban commuter – stands to reduce his or her dependence on fossil fuel by up to 76 per cent, leaving this vehicle owner in the box seat to reap the greatest rewards from using the PHEV in the appropriate context.

These are the parameters for Mitsubishi’s ‘Driver A’, the urban commuter, who can theoretically use EV mode 76 per cent of the driving year:

• Typically travels up to 15,000km a year
• Most of that distance (11,360km) will be in electric-only mode
• The PHEV needs to be recharged to full capacity every second night
• Road user charge (as per Victoria’s charge for PHEVs) is $300 a year
• Longer journeys at weekends will translate to 3640km of petrol consumption a year
• The fuel excise of $93.26 a year, plus the road-user charge totals $393.26 for the PHEV
• The cost to the environment is 502.3kg of CO2 emissions each year

Apply the same calculations to an internal-combustion car that can average 7.2L/100km (versus 6.0L/100km for the PHEV in petrol-burning operation), and this is the result:

• The fuel excise jumps to $461.16
• No road user charge is payable, but fuel excise is incurred for 15,000km each year
• The cost to the environment is theoretically greater – 2484kg of CO2 emissions each year

For the battery-electric vehicle in Driver A’s scenario, the BEV is the lowest taxed.

The only impost is the road user charge of $375.

Driver B is the working parent who Mitsubishi estimates will drive up to 25,200km a year. The car-maker projects that 55 per cent of Driver B’s travel is in electric-only mode.

Using the same method to compare with Driver A, Driver B’s results are as follows:

• Travel is split 13,760km (EV) and 11,440km (ICE)
• Driver B pays $504 for the road user charge and $293.09 for the fuel excise driving a PHEV
• The total is $797.09, according to Mitsubishi’s calculations
• CO2 emissions per year are 1578.72kg for the PHEV and 4173.1kg for the ICE vehicle

This demonstrates Mitsubishi’s case, that PHEV owners are unfairly burdened – despite the PHEV being fundamentally cleaner and better for the environment – contributing more road tax than both ICE vehicle owners and BEV owners:

• Fuel excise for the ICE vehicle will be up to $774.75
• The BEV only incurs the road user charge for an all-up cost of $630

Once again, the BEV is the most affordable to run, although it’s also the most expensive to purchase.

Mitsubishi’s final example is Driver C, the fleet driver who uses the vehicle for work during the week (not just commuting) and for personal reasons at the weekend.

Driver C can be expected to travel up to 40,000km a year, according to Mitsubishi’s calculations. Each weekday involves travelling from point to point seeing various customers and clients.

Here’s how the PHEV shapes up against similar ICE or BEV offerings:

• PHEV reduces fuel consumption by just 34 per cent in this scenario
• Of the 40,000km, the PHEV only travels 13,760km in EV mode
• The remaining 26,240km travelled per year requires petrol consumption
• The road user charge for the PHEV is $800 per year
• Fuel excise in this scenario is $672.27 per year, for a total taxable amount of $1472.27
• Total CO2 emissions for the year amount to 3621.1kg

Once again, the ICE vehicle is taxed at a lower rate than the PHEV:

• Fuel excise for the year is $1229.76
• The BEV comes off best again, with a road user charge of $1000

Mitsubishi’s calculation of EV range and the frequency of recharging – every second night for Driver A, every night for Driver C and ‘a few times a week’ for Driver B – makes little allowance for running lights, wipers and climate control during the winter months, or increased cooling during the summer.

Nor do Mitsubishi’s scenarios and calculations make any allowance for the ‘well to wheel’ emissions of the PHEV and BEV, and nor does the exercise include the CO2 emissions of any of the three vehicle types during the manufacturing process, or the refining of petrol to power the PHEV and the ICE vehicle.

For each scenario, Mitsubishi calculates fuel consumption for the PHEV to be 6.0L/100km, which may not be the owner’s findings in the real world.

A journey in a Volvo XC40 Recharge from Melbourne to Warrnambool for a Christmas break last year used less fuel than that – with climate control operating and four people on board with luggage for a week.

On the other hand, Mitsubishi cites 7.2L/100km for the ICE model in this exercise, but in an urban setting that’s more likely a figure for a small hatch rather than a small or mid-size SUV. In both cases, Mitsubishi has been conservative almost to the point of unrealistic.

In the real world, the disparity should be much greater than the importer suggests, if anything. The figure of 7.2L/100km is more likely to support Mitsubishi’s claim that PHEVs are being unfairly taxed by state and federal governments.

If the figures were 5.0L/100km for the PHEV and 8.0L/100km for the ICE, the tables would be (narrowly) turned in even the worst-case scenario for Driver C.

But the figures are fluid and vary according to everyone’s unique experience. A small SUV might use as little as 7.2L/100km or less if it spends more time consuming petrol while on the open road.

The important consideration is that Mitsubishi’s figures provide a starting point for further discussion.

How to reduce your vehicle tax with a PHEV

• Assiduously recharge the battery to minimise petrol consumption
• Recharge your vehicle’s battery from your solar panels to minimise expenditure and GST
• Claim work travel against your taxable income if you can
• Live in a state that’s more supportive of low- and zero-emissions vehicles