The Energy Reality Behind EVs, Fuel — and Why Plug-In Hybrids Don't Deliver What We're Promised¹²³

Plug-in hybrids (PHEVs) are usually sold as the sensible middle ground:

It sounds pragmatic. Reasonable. Reassuring.

But that framing hides a real problem: PHEVs only work if people behave better than they usually do¹²³. And history — across energy, transport, and economics — tells us the same story every time:

To understand why this matters, we need to start with the fundamentals: energy, efficiency, and what actually moves a vehicle.

The fuel vs EV reality people avoid talking about⁷

Liquid fuels are astonishingly energy-dense.

One litre of diesel contains roughly 10 kWh of chemical energy⁵. Petrol is slightly lower, but in the same ballpark. That density is precisely why humanity moved from horses and whale oil to liquid fuels so quickly.

But energy stored is not energy used.

A modern diesel engine converts only ~25–30% of that energy into motion⁷. The rest is lost as heat through the engine block, exhaust, cooling system, and drivetrain.

In practical terms:

By contrast, a battery-electric vehicle (BEV) converts ~85–90% of electrical energy into motion⁷.

That single difference explains almost everything else.

Why EVs "feel" more sensitive

This also answers a question many drivers notice immediately:

Because EVs are efficient.

In an internal-combustion vehicle, accessory loads (air-con, hills, wind, weight) are small compared to the huge baseline losses already occurring. They're hidden inside inefficiency.

In an EV:

• Every hill matters
• Every headwind matters
• Every kilowatt of air-conditioning shows up

Not because EVs are fragile — but because efficiency makes reality visible⁷.

"EVs just shift emissions to power stations"⁶⁷

This argument refuses to die, and it ignores two fundamentals:

1. Efficiency
EVs need far less energy to move the same mass. Even when charged on fossil-heavy grids, total energy use is lower⁷.

2. Decarbonisation
Electricity grids get cleaner every year⁶. Engines do not.

A diesel vehicle bought today will emit roughly the same CO₂ in 10 years as it does now⁵.
A BEV bought today gets cleaner automatically — without asking the driver to change behaviour⁶.

Where plug-in hybrids go wrong¹²³⁴

Logically, PHEVs should have been a temporary transition technology — a stepping stone from fuel to full electric.

Instead, we rushed early EVs to market with limited range. Consumers didn't trust the promise. And the industry responded by wedging in a compromise that tries to live in both worlds.

That's the core problem.

A PHEV carries:

• an engine
• a gearbox
• a fuel system
• a battery
• an electric motor
• power electronics

It inherits all the complexity of both systems, without fully committing to either.

Behaviour is the Achilles heel¹²³⁹

If a PHEV is not plugged in regularly, what happens?

You get:

• ICE-like tailpipe emissions¹²
• EV-like embedded carbon⁸
• hybrid complexity penalties⁹

That's not a bridge.
That's a compromise — with interest.

PHEVs are conditionally clean, not automatically clean¹²³.

And conditional technologies fail at scale because they rely on human discipline.

What the numbers actually say (15,000 km/year, 10-year life)⁵⁶⁸

When we model real vehicles using conservative assumptions — including embedded CO₂⁸, fuel burn⁵, oil changes, charging behaviour¹²³⁹, and Australian evening grid intensity⁶ — the picture becomes very clear.

Scenario	Operational CO₂ (t/yr)	Total incl embedded (t/yr)	Total lifetime CO₂ (t over 10 years)
A. Diesel ute 8.0 L/100 km, efficiency worsens over time	3.42	4.32	43.2
B. BYD Shark 6 – perfect user 80% electric, 80% solar charging	0.89	2.09	20.9
C. BYD Shark 6 – average user Occasional charging, grid evenings	2.55	3.75	37.5
D. BYD Shark 6 – convenience wins Rarely plugs in	2.75	3.95	39.5
E. BEV ute (Musso EV-class) 100% electric, 80% solar	0.55	1.95	19.5

Read that again.

• A perfectly used PHEV performs well — but only under near-ideal behaviour.
• An average PHEV drifts alarmingly close to diesel.
• A poorly used PHEV is barely better than diesel at all.
• A full BEV ute wins outright, even with conservative assumptions.

This is the uncomfortable middle ground no one wants to talk about.

The BYD Shark 6 proves the point

On paper, the Shark 6 looks revolutionary:

• ~100 km electric range
• ~2.0 L/100 km advertised fuel use
• ~45 g/km CO₂

In reality:

• Perfect users halve lifetime emissions
• Average users barely reduce them
• Convenience-first users erase most of the benefit

That leads to the obvious question:

The diesel comparison nobody wants

A modern diesel ute:

• burns fuel as efficiently as combustion allows
• has predictable emissions
• does not rely on behavioural discipline

That's why poorly used PHEVs land alarmingly close to diesel — despite higher cost, weight, and complexity.

This is the dirty secret of PHEVs:

BEVs don't rely on willpower⁶⁷⁸

A BEV:

• has no oil changes
• has no tailpipe emissions
• has no "forgot to plug it in" failure mode

Even when:

• charged on today's evening grid⁶
• fitted with large batteries⁸
• assessed conservatively

BEVs still win on lifetime CO₂⁶⁷⁸.

And they get cleaner every year without asking the driver to do anything differently⁶.

The EnerLogic, no BS, position

PHEVs are not bad technology.

But they are bad policy bets if:

• incentives assume perfect charging¹²³
• fleets don't enforce plug-in behaviour¹²
• buyers are shown best-case numbers only⁴

If you can charge every night, drive mostly short trips, and want a transitional option, a PHEV might make sense.

But if the goal is real emissions reduction at scale:

EnerLogic
Straight to the point. No BS.