Fossil vs Hybrid vs Electric

Last time, we explored “self-charging hybrids“.

Today I present an overview of the four most common ways of powering a car in 2020 – little disclaimer there since this almost certianly won’t be the case in 2030!

1) ICE – Internal combustion engine car

This car is 100% powered by fossil fuels, i.e. fuels up with petrol or diesel to burn in the “combustion chamber” (engine).

An ICE powertrain
The drivetrain for a petrol powered car

ICE cars get a around 30-55mpg (miles per gallon) in combined (urban and rural) driving conditions.

2) Mild hybrid – what Toyota and Lexus like to call “self-charging”

These are also 100% powered by fossil fuels.

When braking, some energy is recovered from the spinning wheels which feeds a small battery – similar to how a 12-volt battery is charged. The car can then drive a limited distance on this charge. Any physicist will tell you “self-charging” isn’t possible, the energy comes from somewhere – in this case it’s from the petrol that was burnt.

Mild hybrid cars get a around 35-60mpg on average.

3) PHEV– Plug-in hybrid electric vehicle ⛽🔋

These cars can drive a short distance (10-25 miles) on electricity alone. They can be plugged in to charge like an electric car or filled up with petrol and driven like an ICE car.

They have regenerative breaking to recover energy back into the battery. So once they use up their charge, they are effectivly a mild hybrid.

The disadvantage of PHEVs is they are less efficient than EVs in electric mode and less efficient than an ICE cars in petrol mode, since they are carrying the weight of an engine and fuel tank, as well as a motor and a battery.

Plug-in hybrids get a around 50-75mpg on average.

4) EV or BEV – Battery electric vehicle 🔋

These cars are 100% powered by electricity. That energy could come from the UK grid (currently still 30% fossil fuel powered) or it could come from renewables – such as charging solar panels on your roof.

An EV powertrain
The drivetrain for an electric car

Many electric cars have one-pedal driving, recovering energy back into the battery, right until the car stops – the most efficient way of slowing down.

Electric vehicles can achive over 175mpge (miles per gallon electric)!

Here’s another article from the series explaining why electric cars are so efficient. 🙂

How do self-charging cars work?

Toyota, Lexus and Kia use self-charging as a term to describe their hybrids.

Mild hybrid doesn’t sound as exciting or technologically advanced as a self-charging car, which is probably why they market them as that!

How Do Self-Charging Cars Work?

A self-charging hybrid has a small battery and an electric motor. When the vehicle brakes, the initial phase of braking is used to charge the battery. Brakes (disks and pads) then kick-in after.

This is a basic form of regenerative braking (or regen) something plug-in hybrids (PHEVs) and electric vehicles (BEVs) do too, but to a greater degree and effectiveness.

The small amount of energy recovered from braking is then able to be used to drive a limited distance. The battery can only run for around a mile before it needs recharging.

What Powers a Self-Charging Hybrid?

Exhaust pipe emissions on a self-charging car

Unfortunately, a self-powered car breaks the laws of physics, as the energy must come from somewhere. In one of Kia/Lexus/Toyota’s hybrids, the power comes from burning fossil fuels – the petrol in the internal combustion engine.

This means self-charging cars are 100% powered by petrol. All the propulsion achieved is down to petrol – since the cars don’t plug-in.

If we refer to hybrids as self-charging, we should really refer to all petrol and diesel cars as self-charging, since these cars don’t need plugging in to charge their 12-volt battery which powers the wipers, headlights and other electrical ancillery services.

How Far Can A Self-Charging Car Travel?

Toyota et al claim that their mild hybrids can be driven over 50% of the time on “pure electricity”. That makes them seem awfully green, given we tend to associate electricity with being green and petrol with being polluting. This claim is misleading for two reasons:

  1. All the electricity used to driver is generated by burning petrol, so it certainly isn’t the clean energy you can get from the grid or solar on the roof of your house.
  2. It’s crucial to remember that Totota reference time not distance – if you drive in stop-start traffic, the engine might be off for a large proportion of the time as you’re stationary. Some of the slower speed driving may be achievable using the battery, but because the battery is very small, it will drain extremly quickly and require recharging – so the petrol engine turns on. In terms of distance driven, around 1-3% of the distance driven uses the battery. This translats to around 2 miles in 100 miles of driving.

Do Self-Charging Cars Exist?

Will we ever see a car that can power itself? In the Toyota sense of self-charging, no. It’s not possible to drive a hybrid without putting petrol in it.

Lightyear One

However, there are projects like Lightyear One, working to create cars that you may never need to plug-in! These are pure electric cars (not hybrids, so no fossil fuels) and can be charged by plugging-in, or from the solar panels built into the roof, bonnet and boot! ☀️⚡🔋🚗

Lightyear are aiming to be able to charge an impressive 12 kilometres (7 miles) from 1 hour of sunshine charging – using the solar panels on the roof! For those who drive short distances, or travel infrequently, that could mean you’d never need to plug-in!

More info on the Lightyear One in this Fully Charged video.

Should Self-Charging Be Banned?

In Norway (home of the EV, where over half of cars sold in 2020 were fully electric) they’ve banned adverts that reference “self-charging” believing the term is misleading.

I believe marketing a petrol car (100% powered by fossil fuels) as self-charging should be banned. It makes polluting cars that burn fossil fuels seem cleaner and if you don’t do your research, you might think you’re doing your bit to look after the environment when actually, nothing could be further from the truth.

Electric car cost per mile

Last time I looked at the difference in energy usage between petrol and electric cars. Another way of comparing EVs, hybrids and ICE cars is cost per mile. Using the Mini Cooper, we can compare all three. This example is based on UK units, assuming petrol is costs £1.30 per litre and electricity 14p/kWh – i.e charging at home.

Petrol

The petrol Mini Cooper S has a 44 litre fuel tank, and an average consumption of 44 miles per gallon – UK/Canadian mpg. A full tank of fuel can take the car 425 miles at a cost of £57.20, meaning each mile of driving costs 13.5 pence.

Hybrid

The Mini Countryman Cooper S plug-in hybrid has a 36 litre fuel tank and a 7.6kWh battery. Combined mpg figures range from 50.8mpg to 56.6mpg so we’ll use 53.4mpg for the comparison.

That means with a full tank and a full battery, you can travel around 423 miles – similar to the petrol car. The cost of 36 litres of petrol is £46.80 and 7.6kWh of electricity costs £1.06, making the total cost per mile around 11.3 pence.

Electric

The Mini Cooper Electric

The Mini Electric has a 32.6kWh battery and a range of 115 miles. It costs £4.56 to “fill up” the battery meaning each mile costs 4.0 pence.

Hybrid Inefficiencies

Interestingly, the hybrid is less efficient than the electric car when running on battery power and less efficient than the petrol car when running on the petrol engine. This is because it’s not just carrying an engine and a fuel tank, or a motor and a battery pack, it’s carrying all four all the time!

Hybrids were a great tool in the transition from ICE to EV, proving the concept and raising awareness. I believe they are no longer relevant however, as they’re significantly less efficient than their EV counterparts and don’t offer the electric range that people really need. The addition financial and efficiency costs don’t make hybrids worthwhile.

Most Efficient Car Pence Per Mile

The Hyundai Ioniq Electric

We’ve already established electric cars are far more efficient than petrol and hybrid-powered cars, so what’s the best of the best, the most efficient electric car? That title is shared by the Hyundai Ioniq Electric and the Tesla Model 3 Standard Range Plus which use just 240 watt-hours of juice per mile.

The Ioniq can drive an impressive 160 miles on a 38.3 kWh battery pack. It costs £5.36 to charge empty to full, at a cost per mile of 3.4 pence.

Just 3.4 pence for every mile of travel! That’s a quarter of the cost of the petrol Mini Cooper S!

The Model 3 can drive 195 miles (140 in winter, 275 in summer) on its 50 kWh battery pack. 50 kWh costs £7.00 on a £0.14/kWh home supply, which gives it a cost per mile of 3.6 pence. Worst case that’s 5.0 pence per mile in winter, best case it’s as low as 2.5 pence per mile in summer.

EV Tariffs

Some electricity providers now offer electric car tariffs, which make it even cheaper to charge. Some even pay you to take power off the grid when demand is low but supply is high!

£0.05/kWh is not uncommon. Charging a Model 3 at that price could give you 275 miles of range for £2.50.

0.9 pence per mile.

Petrol cars simply can’t compete with electric cars on pence per mile. EVs are too efficient 🙂