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.

How many miles per gallon do electric cars get?

Electric cars aren’t powered by diesel or petrol, so they don’t have an official miles per gallon figure. That said, there are ways of working out how efficient they are and even give them a rough miles per gallon.

How Many Kilowatt Hours is in a Gallon of Petrol? ⛽

The US governments fueleconomy.gov website calculates 1 (US) gallon of gasoline is equivalent to 33.7 kilowatt hours of energy – or kWh.

A US gallon is 3.785 litres, whereas in Canada and the UK a gallon is 4.546 litres. This means a (UK/Canadian) gallon of petrol is equivalent to 40.5 kWh of electricity.

Each litre of petrol is equivalent to 8.9 kWh.

Toyota Prius vs Nissan Leaf MPG

The Toyota Prius was once regarded as the sustainable choice for environmentally conscious drivers, but in recent times its crown has slipped a little. This might be partly because of Toyota’s inaccurate branding, claiming that it sells “self-charging cars”, when in reality a (very small) battery is charged by recovering motion which was achieved by burning petrol or diesel. That’s how most cars charge their 12-volt battery, it’s not self-charging! 😂 It’s also because electric cars are now more viable and mainstream.

The Nissan Leaf is currently the top-selling electric vehicle of all time (at least until the Model 3’s first quarter sales are released) so let’s use that for the comparison. An “efficient” hybrid vs an electric vehicle, how do they compare?

The Nissan Leaf

The Totoya Prius achieves 62.4mpg (UK/Canada) using 4.5 litres to travel 100 miles. The Nissan Leaf by comparison achieves the equivalent of 129.7mpg (UK/Canada) taking just 2.2 litres to travel 100 miles.

This highlights the efficiency of electric vehicles.

The Leaf uses less than half the energy of the Prius (the previous “gold standard”) to travel the same distance.

Efficiency

Internal combustion engine (ICE) powered cars convert around 12-30% of the petrol or diesel they consume into forward motion powering the wheels. This is because an ICE car loses over two-thirds of its energy through heat 🔥 and the transmission of power through the drivetrain.

Even the most inefficient electric vehicles translate at least 60% of the electricity stored in the battery into forward motion. If driven using regenerative braking (to re-capture energy, rather than scrubbing it off via breaking) EVs can be around 90% efficient!

How Big is an Electric Car’s Fuel Tank?

Electric car battery and powertrain

Here’s another interesting question, if an electric car had a fuel tank, how big would it be?

The Tesla Model 3 Standard Range Plus has a 50kWh battery, so if one US gallon of gasoline/petrol is equivalent to 33.7kWh, then the Tesla Model 3s equivalent petrol fuel tank would be 1.48 US gallons – or 5.62 litres.

That’s right, an electric car can achieve a range of 200 miles (275 if driven carefully in warm weather) on less than the equivalent of 6 litres of petrol!

You can also compare cars on a cost per mile basis, which is what I’m going to write about next, with the help of the new electric Mini!