Note: This advice is given by the CAP Executive about non-broadcast advertising. It does not constitute legal advice. It does not bind CAP, CAP advisory panels or the Advertising Standards Authority.


In 2021 and 2022 the ASA and CAP undertook a Climate Change and the Environment (CCE) project taking stock of the rules regulating environmental claims.  This project consisted of three concurrent strands:

  • Proactive regulation: proactively looking at environmental claims in several priority areas with a view to updating our position on emerging and existing themes and taking action against advertisers who use green claims in a way that is likely to mislead or cause harm. 
  • Standards fit for the 2020s: taking stock of how effective our rules and guidance are in governing environmental claims. 
  • Knowledge, education and communication: updating our existing resources to make them easily accessible, and creating new training materials and other educational resources to improve industry’s understanding and overall compliance with our rules on misleading and harmful environmental claims.

While this advice represents the current position, the ASA’s CCE project is now reviewing our approach to these issues, which may lead to further rulings and updates to this guidance.

With an increase in the number of electric and hybrid vehicles available to consumers and the increasing competitiveness of the market, the ASA has seen a corresponding rise in the number of complaints about the marketing of such vehicles.

This guidance gives an overview of some key considerations in terms of advertising fully electric or hybrid vehicles.

Emissions while driving

Absolute environmental claims

Clarity about the technology involved

Hybrids and fuel consumption claims

Many complaints relate to the claimed efficiency of the vehicle: the claimed miles per gallon a plug-in hybrid vehicle can achieve, or the emissions released (either directly or indirectly, through the production of fuel), for example.

At a time when the market for these vehicles is growing rapidly and looks certain to accelerate, marketers should bear in mind that advertising which highlights a vehicle’s technology, such as the way in which a particular type of hybrid vehicle operates or the charging infrastructure for electric vehicles, should always be designed to be clearly understood by consumers.

Emissions while driving

While advertisers are likely to be able to demonstrate the environmental benefit of using an electric vehicle compared with a petrol or diesel alternative, particularly in terms of localised emissions and the effect on air quality, they should make sure their claims do not overreach.

An ad for Hyundai’s hydrogen fuel cell powered electric SUV, the NEXO, was considered misleading when the ASA investigated a complaint in 2021.

Text on Hyundai’s website included “Introducing the next generation of fuel cell vehicles: All-New NEXO. A car so beautifully clean, it purifies the air as it goes”. Hyundai explained that the NEXO’s fuel cell produced electricity by combining oxygen and hydrogen. A supply of clean air was essential to provide this oxygen, and the system therefore acted to filter air and removing fine dust and gases. Purified air was then expelled from the system.

The ASA considered that the claim “a car so beautifully clean, it purifies the air as it goes” would be understood to mean that the car, overall, had negligible environmental impact, and that it would remove impurities from the air as it was driven meaning that no impurities caused by driving would remain in the air.

While accepting that the NEXO’s systems would purify and remove harmful particles from the air as the car was driving, the ASA noted that particulates from brake and tyre wear would still be released from the car, and these might not necessarily be removed by the car’s filtration system. It considered, therefore, that the headline claim had not been adequately substantiated and was likely to mislead. While this ruling relates to an, at present, rare type of electric vehicle, the principle would apply to advertising of any EV (Hyundai Motor UK Ltd, 9 June 2021).

Absolute environmental claims

It’s not just advertising for cars that risks misleading consumers about the environmental impact of transportation. An ad for an e-scooter which said ““be environmentally... friendly take a TIER” was ruled to misleadingly imply that the scooters caused no environmental damage whatsoever.

The advertiser said that the claim was intended to be implicitly relative, aimed at people who had a selection of travel options available to them, such as petrol cars, or non-electric buses. They provided evidence to support this interpretation, which they said demonstratrated the relative lack of negative environmental impact from using an electric scooter as opposed to another means of transport.

The ASA considered that the claim would be interpreted as an absolute claim that the scooter would cause no environmental damage at all throughout its lifecycle. The advertisers evidence showed that the production method would result in emissions and some negative effect on the environment, and the ASA therefore considered the ad to be misleading. (TIER Operations Ltd, 6 April 2022).

Clarity about the technology involved

Two ads, about vehicles powered by Nissan’s ePower petrol/electric system were ruled to be misleading because the nature of the cars’ power source was not made sufficiently clear, and the precedent set by this ruling would apply equally to non-broadcast media. 

These TV ads showed sparks being thrown off an electrical transmission tower and following the car shown, along with a voiceover said “Who said electrification can’t spark excitement when unplugged?”. Onscreen text said “FUELLED BY PETROL DRIVEN BY ELECTRIC”, “NO NEED TO PLUG IN” and “New Nissan Qashqai with e-POWER. A unique electrified experience, unplugged”.  Nissan explained that the cars’ wheels were powered purely by an electric motor, which in turn was charged,  directly or indirectly, by a petrol engine, as well as through the cars’ regenerative breaking systems. The ASA considered that the ads placed strong emphasis on electricity as a means of power and the reference to “e-Power” could be understood as meaning that the cars a new, electric technology, acting in the same way as purely electrically powered vehicles that did not require the car to be plugged in was being offered.

The ASA concluded that the ads were misleading and highlighted that similar claims in future should clearly explain the nature of the vehicle’s power source.

More generally, the ruling also highlights that the focus on the cars’ use of electricity would be understood as suggesting the cars were a better choice for the environment than more traditionally powered vehicles. The fact that petrol was needed to indirectly power the car was seen as material information relevant to a consumer’s understanding of this claim and, given that the ASA considered the ads did not make sufficiently clear that the cars did require petrol, they were also ruled misleading on this point. As such, advertisers should take care to ensure that the overall impression of an ad does not exaggerate or mislead about a car’s environmental impact, whether relative to alternative products or as an absolute claim (Nissan Motor (GB) Ltd, 18 October 2023).

An ad describing a car as a “self-charging hybrid”, however, was not upheld as the ASA considered the ad was unlikely to mislead consumers.

The complainant objected that the claim “self-charging hybrid” was misleading because they believed it misrepresented the way in which the electric battery was recharged by using the petrol engine.

The advertiser explained that claim “self-charging hybrid” was intended to refer to the overall vehicle being self-charging, rather than the battery or any other individual component. They believed that consumers would be aware that a hybrid vehicle was powered through a combination of petrol and electricity.

The ASA agreed that the word “hybrid”, in a motoring context, was likely to be interpreted by consumers to mean that a vehicle was powered by a combination of a petrol/diesel engine and a re-chargeable electric battery. The ruling notes that there was no implication that the battery was charged via plugging in. It concluded that the claim “self-charging hybrid” was likely to be understood to mean that the internal mechanics of the car would charge the electric battery (Toyota GB plc t/a Lexus, 13 November 2019).

Hybrids and fuel consumption claims

The ASA also considered a complaint about the Mitsubishi Outlander plug-in hybrid electric vehicle that claimed it was "capable of 148 mpg". Further text on the website went on to state "32.5 Mile Electric Range Capable of 32.5 miles in EV mode, the average commute can be driven solely on electricity reducing the cost on you and the environment". The complainants, who understood that the fuel consumption figure quoted in the ads was unlikely to be replicated in normal driving conditions and that it was based on the car’s battery being fully recharged from an external source at regular intervals, challenged whether the ads misleadingly implied that the car could travel 148 miles on one gallon of fuel alone. The ASA considered that the advertising did not make clear that the claimed MPG figures might not be achieved and agreed that the ad did not make sufficiently clear that the fuel consumption rate related to the rate achieved through a combination of mains electricity and petrol fuel. It therefore considered the ad misleading (The Colt Car Company Ltd t/a Mitsubishi Motors UK, 13 August 2014).

An ad for proposed electric vehicles claimed “… the well-to-wheel efficiency of a Renault Fluence Z.E. will help reduce CO2 emissions by at least 90% compared to a current Diesel model* ...”

Small print below stated “… *Comparison between a Renault Fluence Z.E. (basis: French average electric mix) and a model from an identical category: Renault Megane Hatch 1.5 dCi (85HP) emitting 133g CO2 well-to wheel.”

A complainant challenged whether the claim was misleading because electricity generation in France produced significantly lower levels of carbon than that of the UK. The ASA noted that the ad was qualified and stated “basis: French average electric mix” but considered that the average consumer was unlikely to be aware of the difference in CO2 production between electricity generated in France and the UK. It concluded the claim exaggerated the likely CO2 saving in the U.K and was therefore likely to mislead. (Renault UK Ltd, 5 May 2010)

Marketers of electric vehicles should take care when making savings claims related to their vehicles fuel economy. One marketer assumed a year-on-year increase in the price of petrol as part of the calculation they relied on to justify a comparative savings claim. The ASA considered that the price of petrol could go down as well as up and that a predicted future increase was therefore not a suitable basis for a savings claim calculation. The ad was therefore considered misleading (Toyota (GB) PLC, 15 February 2012).

See also:

Motoring: Fuel consumption and emissions figures

Environmental claims: Motoring

Fuel accessories and after-market devices

Environmental claims: General “green” claims

Advertising Guidance - misleading environmental claims and social responsibility


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