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Fuel for thought - which car fuel type truly costs less to drive? And does ULEZ make a difference?

The cost of electricity has soared over the last couple of years, but likewise petrol and diesel fuels have also gone up. In the article below, we aim to answer which fuel type is actually cheapest for your commute and how expanding ULEZ zones in the UK affect this.

First factor: Increasing fuel costs

The impact of the Ukraine war on energy costs has been felt across society, but how much has it affected car fuel costs?

Fuel Type Sept-21 Sept-22 Sept-23
Petrol £1.35 p/gallon £1.65 p/gallon £1.53 p/gallon
Diesel £1.36 p/gallon £1.81 p/gallon £1.55 p/gallon
Electric: Slow/Fast Charge (3-22KW) £0.23 p/kWh £0.42 p/kWh £0.51 p/kWh
Electric Rapid/Ultra Fast (25-99KW) £0.37 p/kWh £0.63 p/kWh £0.76 p/kWh

As of September-23, both petrol and diesel prices are up around 12 percent on pre-war, September-21 prices1. Electricity prices have surged dramatically, with the average cost to rapid/ultra charge an electric vehicle at a public charging station up 105%2.
According to the Energy Saving Trust, on average 80% of electric car charging happens at home through a 3-22KW charger, giving a weighted average cost p/kWh to charge an electric vehicle of £0.563.

Secondary factor: Emission zones expansion

Emission zones have been expanding in the UK as of late - most recently the ULEZ expansion in London on the 29th August 2023. Having a non-compliant ULEZ vehicle for your commute can really start racking up costs with the London ULEZ charge costing £12.50 per day.

Which vehicles fall foul of ULEZ?

For petrol cars, engines with emission standard Euro 4 (NOx) or higher, which is the vast majority of cars produced after 2006, are compliant with ULEZ. However, diesel cars are a lot more stringent, with the majority of pre-2015 production cars not being compliant - diesel vehicles require a Euro 6 (NOx) engine emission rating.

As of March 2023, over 90% of cars in Greater London meet ULEZ standards4, but data from the DVLA suggests there are nearly 700 thousands registered cars in Greater London at risk of ULEZ daily-fees5. Only 81 percent of Diesel cars registered in London have the required Euro 6 (NOx) rating or higher6. Cars such as older Ford Focus models, VW Golf MK6s and the E90-93 generation of the BMW 3 series fail ULEZ.

Which localities have emission zones?

The government’s push to reduce emissions from private vehicles has resulted in a growth in low emission zones throughout UK city centres:

Location Requirements Daily Cost Year and Month Introduced
Birmingham Petrol: Euro 4, Diesel Euro 6 Up to £50 June 2021
Bristol Petrol: Euro 4, Diesel Euro 6 £9 November 2022
London Petrol: Euro 4, Diesel Euro 6 £12.50 April 2019 (ULEZ), August 2021 (expansion), August 2023 (expansion)
Oxford All private cars other than electric lower rate - higher rate for more polluting cars £2- £10 February 2023

So how much does it cost to commute through a ULEZ zone?

For the purposes of having a commute to compare cars and fuel types against - we will say that an average driving commute into London could be St Albans to Walthamstow, which reaches the ULEZ zone:

Our example commute

We will also imagine that you drive into work 5 days a week, 20 times a month.

Comparing Popular Cars

Next we will compare a series of cars based on popularity:

  • Ford Puma Petrol - the highest selling petrol car 2023 to date.
  • Tesla Model Y - the highest selling electric car 2023 to date.
  • Ford Puma Diesel - the highest selling diesel car 2023 to date.
  • 2013 Ford Focus 1.6 TDCi Diesel - most popular diesel car which is non ULEZ compliant.
  • 2003 Ford Fiesta 1.4 Petrol - most popular petrol car which is non ULEZ compliant.

Looking at real user experience for car efficiency in terms of MPG and Wh/Mi, alongside fuel cost data from Sept-23 we've worked out how much each commute would cost in the different vehicles:


The winner of our research is the Tesla Model Y, with this commute costing either £108 or £118, based on slow or balanced charging, per month.

However, be warned that if you have an electric vehicle and rely on ultrafast charging networks your commute would raise to £161 per month which is actually more expensive than a modern petrol or diesel car! The diesel Ford Puma would cost £135 p/m and petrol version £143 p/m.

This research also goes to show how expensive driving a non-ULEZ compliant vehicle in London now is, where an additional charge of £12.50 per day will stack up to £250 per month, if commuting 5 days a week.

This means that those with a 2013 Diesel Ford Focus could now face a monthly commute of hundreds of pounds - £392 in our example.

Check out your commuting costs

If you're interested to find out how much your driving commute costs use our handy Cost of Commuting Calculator which works with petrol, diesel and electric vehicles.


  1. Fuel Watch Advice | RAC
  2. EV Charging Price Index | Zap-Map
  3. Charging Electric Vehicles - Best Practice Guide | Energy Saving Trust
  4. Press Release: ULEZ Standards Compliance in Outer London | TfL
  5. News: ULEZ Payment Liabilities in Greater London | RAC
  6. Expanded ULEZ Six Month Report |