Electric Cars, BBC Sounds, Best Thing Since Sliced Bread presented by Greg Foot.


ceteris paribus


  1. With all other factors or things remaining the same.
  2. other things being equal; with all other things or factors remaining the same.
  3. all other things being equal

Anyone that has done O-grade economics knows what ceteris paribus means. It means nothing in the real world, because all things are not equal. Since the late nineteen-seventies, year on year, decade on decade things have grown more unequal. A simple question what is better a Vauxhall Corsa powered by an electrical battery, or the around £8000 cheaper petrol motor? Most folk rent cars and don’t buy them outright. Ford motor company, for example, was largely kept afloat not by making cars, but leasing them, and when that model no longer worked they were bailed out by the American government. Too big to fail in the money market. Vauxhall admit that around 90% of their cars are leased and not bought. By 2030 they and other car manufactures will stop making cars with an internal combustion engine. If you want to know why Elon Musk is one of the richest men in the world it’s that simple fact. Cars with an internal combustion engine are already been squeezed out of cities like London by hefty tax charges. Other big cities will follow. I’m glad of that. But we’re way behind in the changes we need to make to making it workable. Every home needs a charging point. But not every person that needs a home has one. Millions can’t afford to heat them. EVs win in the neoliberal world of ceteris paribus. It makes sense to be rich and make rational economic decisions.


Lots of arguments it’s good for the planet. Lots of argument you can save money. That advert made none of those claims.

Huge rise in popularity of Electric Vehicles (EVs). Is it worth switching?

1 in 6 vehicles sold last year, 2021, were EVs. More EVs sold last year (2021) than all of the five years combined.

Should I switch?

Does it really make sense, scrapping my old car, 30 000 miles on the clock, small engine? Or should I just run it into the ground?

UK Government announced a ban on sale of new petrol/diesel car by 2030. But that doesn’t mean if you have a petrol car you need to swap it for an EV by 2030. 

How many miles would I have to do in this new EV before it offsets those carbon footprint of consumption and actually is the greener option?

And new EV thousands of pounds (cost) more than a petrol car. How far do I have to drive the EV before I have to recoup that initial extra cost?

I’m Mike Berniers-Lee, I’m, Professor of Sustainability at Lancaster University. Author on There is No Planet B.

Test the footprint of an EV v a petrol engine or internal combustion engine (ICE) how would we go about doing it?

I would take two microlight products, close to like as like can get. The petrol version of a car and EV. Then I’d estimate the embodied carbon in manufacture.

I’d make an assessment of carbon per mile (cpm) for each vehicle.  

I would do a calculation for how many miles it would take for the EV to break even, or how many miles around the race track.

Predictions from experts and whether Julien should switch from an ICE to EV. 

I’m Dr Euan McTurk and I’m a consultant electro-battery chemist.


Spent over a decade working and driving EVs. Working on chemistry batteries to improve their range and performance.

What is the point you start recouping your costs over ICE car? Any idea how many miles it would take before you start breaking even?

A: The savings you would make, especially, if you are a higher mileage driver—I was doing 12 000 miles per year—for example, and I was still saving a significant sum of money, well into the four figures every year, if you’re factoring in the residual value of the car—what you would get if you sold it—after how many years, that break-even point between buying an EV outright and buying an ICE car outright is probably a couple of years for a lot of people, then you are laughing your way to the bank.

We’re going to test an electric Corsa? To see how many miles we need to drive before we offset that carbon footprint. 

How many miles do you think we’re going to need before we offset?

A: I’d be gobsmacked if it was anything above 40 000. More realistically, finger in the air, around 20 000 miles, worst case. EVs then go sailing past it. I’ll be interested to find out the result. Keep me posted.

Vicky Parrot, freelance motorist journalist. Specialised in EVs, so I’ve been doing this now since about 2006.

Let’s talk about the environmental concerns then, because you have written, in some cases, ‘the greenest option, is to keep driving your petrol car’. Not to switch?

A: Effectively, if you don’t do very many miles. It is potentially, actually, greener to keep an old petrol car on the road, even if it’s only doing 30 mpg or something like that. It’s not just the fuel you burn. It’s also about the energy involved in recycling the car. And it’s crass to just scrap perfectly useable petrol and diesel cars. Despite the fact, I do love EVs and do advocate people buying them. If you’re only doing about 5000 miles per year, which plenty of people do, then you’re not going to make up the cost of a new EV in your fuel savings.

We’re going to test an EV v and ICE, what are your guesses for what that figure will be?

A: Blimey! I’ll get my crystal ball out and I’d say about 30-40 000 miles. To offset the complete manufacturing burden.

The predictions are in. I’ve got my hands on the cars, which means it’s time to test. The race track was we are going to do the experiment. Two pretty identical cars. One notable difference. One of them doesn’t have an exhaust pipe. Vauxhall Corsa. Vauxhall E-Corsa.

We’re here to drive them a set number of laps around the track. To work out the real-world miles-per-gallon and miles-per- kilowatt (KW).

What is that break-even point?   

Should Julien ditch his old petrol guzzling car for a new EV?

Petrol car, first. I’m going to go ten laps around this track. Then I’m going to drive the car to the petrol station and we’re going to fill it up.

Odometer set to zero. Petrol filled to brim. Allows us to know how much we filled up by. How many miles we’ve covered. By that we can work out mpg.

Current price at petrol station 167.9. 1.39 litres at a cost of £2.33. 13 miles to get to the track. 10 laps around the track. Back to petrol station.

E-Corsa. Do it all again. Can’t hear a thing. I’m in the petrol station. Odometer to zero. Battery percentage. Eight bars. We’re at 7.1.

Taking my foot off the speedometer at the first bend on the track. And it’s charging the battery because of that regenerative process. Take your foot off the brake. And they grab some of that energy to put more juice in the battery. Every time I slow down on these bends, it’s giving me a bit more oomph (on the battery).

How much has the battery been depleted?

Battery, 6.6 (out of 8). 82 and a half percent. Drop of 6.5 percent.

I’m told by Vicky and those at TopGear this is the first time a real-world test has been done. Spreadsheet. I’ll put it on social. Where I’m @GregFoot.

ICE = 42 mpg. Cost per mile: 18p. However, with drop in UK fuel duty, typically, came in the day after the test, that becomes 17.5p per mile for petrol Corsa.

E = 4.16Kwh. Cost per mile: 5p. However, got to update this as well. UK price cap that came in last week, means that goes up to 7p per mile.

Petrol, 17.5p v 7p for E-Corsa.

Every mile Julien (hypothetically) would be driving, he’d be saving ten-and-a-bit pence.

The big reveal, how many miles Julien need to drive to offset the price of the car, or where the break-even point where he to buy a new more costly EV or petrol car?

How green it would be to switch?

I need those missing numbers for Mike Berniers-Lee.  

Mike Berniers-Lee: There are some obvious paths of the manufacture of the car, like the big, bulky bits. Like the chassis and the engine, which has clearly got a lot of metalwork. There are also smaller components. Especially, electronic components that have lot of high-spec, very technical manufacturing. A chip may only weigh one gram. Could have a much bigger carbon footprint by just looking at the size of it being a small object.

Best estimate for the E-Corsa with 50KW-hour battery, the carbon footprint will be around 12 tons of CO2 equivalents. A big part of that is that huge battery.

Petrol equivalent, same car, we estimate the CO2 equivalents comes in at just over half that at a much smaller, 6.7 tons of CO2 equivalents.

Greg Foot: Crikey! You mentioned full-life-cycle analysis earlier. This is…I don’t know, because you haven’t given me (we don’t know, how long/far it will be driven). Is this just for the production?

This is for the brand-new car. At point of sale. Before you’ve driven it off the forecourt. 

GF: That’s eye-opening, the electric is almost double the carbon footprint of the petrol.

MBL. Sorry, for a sense of scale. That 12 tons is roughly the total carbon footprint of the average UK person over a year. It’s a similar order of magnitude. It’s a big carbon footprint in terms of personal living.

Switching Julien’s petrol car would roughly double his carbon footprint. I’m ready to reveal the results to Julien.

What do you want to know first for the money or the planet?

Julien: I think I’ll go for the cold, hard cash.

OK, to decide whether you should switch from your working petrol car for new EV, you wanted to know how many miles would you need to drive before the money you saved on petrol covered the cost of buying a new EV.

Each mile on a EV, saves you around 10p, compared to a mile in petrol

Julien: Wow, so that could add up quite quickly, I guess.

Well, not that quickly if you want to save the price of a new electric Corsa at almost £32 000. Your looking to drive almost 300 000 miles. Or if I give you that in terms of average-annual mileage of about 7000 miles. You’d need to be driving more than 40 years. I haven’t factored in the savings you’re going to make on road tax each year. Or maintenance costs. Plus, you’re going to likely sell your old car, which would make the net-cost of that old EV lower. So it would take the time it would take you to offset that initial cost.

If you were at that point where your old petrol car is beyond repair. And that was before 2030. And you’re trying to decide whether to buy a new EV or a new petrol. And again, we’re just thinking of financial then. How far would you need to drive? Before savings covered that initial cost?  

Well, there’s a price difference of around £8 500 between ICE and EV Corsa. Which means that after the recent price risen and changes to fuel duty, you’re looking to be driving at least 80 000 miles, which would take you just over 11 years on average annual driving. That’s quite a commitment on the same car.

It raises the question, can I look at myself and see myself driving this in 11 years to make this financially worthwhile?

And that’s with the cheapest way of buying a car. And that’s with cash up front. And it you’re not going to drive that car for 11 years. You’re probably going to sell it. And EVs seem to keep their value, very well, now.

What about the planet? How far would I have to drive this car to lesson my carbon footprint.

Driving an EV isn’t totally clean. I looked at the energy mix on the day of the test. Fewer than 1 in 3 miles I was driving in the EV was powered by truly renewable energy. Because on that day, which I think is what the energy mix looks like, nearly 40% of energy was coming from fossil fuels. Which means that although it has no hose pipe the electricity that’s gone in there has been made from the result of burning things. Burning gas, specifically. But each of those miles is significantly cleaner than driving them in a petrol car by a factor of 5 or 6.

And when I take Mike’s figure. And our real-world test figures, my best estimate for how far you would need to drive before those environmental savings you’re getting from using electric rather than petrol add up, and start to offset that carbon footprint of making the EV in the first place is a bit over 37 000 miles.

Julien: That’s more than what’s on the clock on my car, already.

Greg Foot. And if you don’t think you’re going to drive it that long, or so far, then you’re likely going to sell the EV, when you’re done with it. Somebody else is going to continue to offset that initial production. So it’s pretty likely that you were at that point, your old petrol car is beyond repair, and you’re going to buy a new car. And you’re deciding whether that’s going to be petrol or electric. That’s before 2030.  Then the numbers change. The additional carbon debt of buying a new EV compared to a new petrol car will be offset when you have driven, best estimate, 16 500 miles. Which would take you on average two and bit years of driving.

Julien, stick or twist?

As things stand now, I don’t drive more than 5000 miles. I get the train. I walk. I haven’t been on a plane in about six years. So to me the arguments for sticking are much stronger.

We put these results to Vauxhall, and we heard from their head of PR. He said that their parent company has the figures for the manufacturing carbon footprints of cars but he hasn’t shared them with us.

He also said very few people keep a car from 11 years. And more than 90% of Corsa customers do not purchase their vehicles outright. Instead opt for a personal contract purchase  (PCP). In this instance it is the monthly cost it is most relevant to consider. And not solely the on the road price. 

Battery life for the EV vehicle will easily outlive the car usage.






There was an article in the Times recently about the approaching 2030 deadline. Seems incredibly unrealistic to expect everyone to switch to electric/hybrid when the cars cost so much more. So what happens to the 2nd hand market? Will it be upgraded with "cleaner" cars for sale at current price levels. Economically, this is a ticking time bomb. Can the government diffuse it in time?


the government is looking the other way and hoping someone will step in and solve the problem. Too little. Too late.