The Dunlop Grandtrek PT30 is a summer tyre with a B rating for fuel efficiency, C rating for wet grip and a noise level of 67dB. If you are satisfied with their performance then there is no reason not to continue with them. There is no tyre in a 225/60R18 size that offers better performance in all three areas, but the Hankook Ventus Prime is rated B for fuel efficiency, A for wet grip and a noise level of 69dB. We would suggest using a website such as blackcircles.com where you can enter your registration number or tyre size and view a range of tyres from different brands for your vehicle.