Which luxury SUV offers good comfort and a quiet ride?

I have a four-year-old facelift Jaguar XJ 2.7 V6 diesel Sovereign, which I have owned from new and now has 98,000 miles under its belt. It has been a wonderful car, smooth, quiet, economical and reliable, but is now worth very little. I am looking to change to one of the following, all diesel, either new or low-mileage and high-spec: the Range Rover Vogue SE, Porsche Cayenne, Mercedes S-Class or Jaguar XJ. Which would you choose for comfort and a quiet, smooth motorway ride?

Asked on 31 March 2012 by JC, via email

Answered by Honest John
1: Jaguar XJL 3.0V6 diesel on 19-inch wheels rather than 20-inch: www.honestjohn.co.uk/road-tests/jaguar/jaguar-xjl-.../
2: Range Rover Sport 3.0V6 diesel on 19-inch wheels (Range Rover too tall to corner as well): www.honestjohn.co.uk/road-tests/land-rover/range-r.../
3: Mercedes-Benz S-Class.
4: Porsche Cayenne.
5: Volkswagen Touareg (similar to Cayenne underneath, but cheaper).
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