Our reader lives on the edge of the London Ultra Low Emissions Zone (ULEZ). His question is ‘should I sell my diesel Cayenne or hang onto it for a few years’.

Is the Cayenne ULEZ complaint?

The reader’s 2011 Cayenne with its 3-litre V6 diesel engine is rated Euro 4. This was the emissions standard that cars up to 2015 had to conform to.

To enter the ULEZ without paying the £12.50 charge, you need a car that’s Euro 6, demanded for vehicles from 2015 onwards.

Will the price of diesel cars fall over the next few years?

The question that our reader is concerned about is whether they should sell their car or hang onto it. They seem perfectly happy with it, other than it’s not ULEZ compliant.

The price of used diesel models does largely depend on the general market for second-hand cars. The price of used diesel cars is falling in comparison to petrol models. But it’s unlikely to collapse. What’s more, used car experts reckon the price of large used diesels is declining more slowly than smaller models.

And currently, the slowdown in new-car deliveries due to the computer chip shortage means there’s a lack of good quality used cars around. That in turn is pushing the prices of used cars up.

On top of that, it’s worth remembering that the Porsche Cayenne has always held its value well compared to other used cars. Although there are plenty of people who hate diesel cars, we don’t think the desire for, and prices of diesel cars will collapse in the short term.

Longer term it’s impossible to say because the government might decide to up the duty on diesel to encourage people out of their diesel models. But we think that’s unlikely because of the ructions it would cause in the haulage industry.

Will prices of combustion engine cars fall?

At the moment it depends on how the transition to electric vehicles (EV) goes. If it goes well with plenty of charging points to make EV ownership more viable, people probably won’t have too many qualms about the move away from petrol and diesel. If the switch goes badly, the value of combustion engine cars is likely to stay strong.

So should they sell their Cayenne?

If they like the car, we think there’s no reason to sell it. Yes, its price will fall over the next couple of years, but only in line with regular depreciation. And even in a couple of years’ time there’s still likely to be demand for quality large diesel cars, simply because they’re more efficient and cheaper to run than equivalent petrol models.

Will more UK cities adopt ULEZ soon?

London was the first, followed by Birmingham which introduced its ULEZ for polluting vehicles in the summer of 2021. Bath too has one in place, although it doesn’t apply to private cars.

In Scotland, Aberdeen, Dundee, Edinburgh and Glasgow plan to charge more polluting cars. In England, Newcastle, Bradford, Liverpool, Manchester, Oxford, Bristol and Portsmouth also have plans to put their own ULEZ in place over the coming months.