What do you think of Elon Musk? Have your say | No thanks
Why does fitting wider tyres increase a car's emissions?
In your column 14 January, MV of Thatcham stated that "larger diameter rims increase exhaust emissions," but did not say why. I can see that average engine revs will be lower for the same journey average speed but I, and I expect other readers, would welcome further explanation.
Asked on 21 April 2012 by DT, Abingdon

Because the rolling circumference of their tyres is about the same so they invariably come with lower profile, wider tyres creating more drag and increasing the CO2.
Similar questions

I own a Jaguar XF Sportbreak Estate, which has 20-inch alloys with low profile tyres. I find the ride most uncomfortable as it's very hard and susceptible to uneven road surfaces. I'd like to improve the...

I have recently purchased a Skoda Octavia which is fitted with low profile tyres. Can it be fitted with normal tyres? The existing tyres are 225/40 R18

I have Diamond Cut wheels on my Skoda Superb Estate. Can you please offer some damage protection advice? I realise the best advice is to drive properly and not kerb wheels, but with low profile tyres it...