You might improve it slightly with a fresh air filter and BP Ultimate diesel. But that's about what I would expect from this vehicle. It's huge and blunt, carrying a lot of weight, a 4WD system and saddled with an autobox (though that should 'lock up' on the motorway). My brother gets 30 - 33 from a Navara, which is the same thing with a solid rear axle and less weight. I can tell you that the Isuzu I-TEQ 2.5 and 3.0 engines are more economical. I got 34mpg out of a 2.5 4WD. Our own 2.5 2WD does 36. And readers report over 40 from the 3.0 2WD. A LandRover Disco III 2.7TDv6 struggles to manage 25mpg. Don't confuse VCA figures with manufacturer's claims. They are not "manufacturer claims". They are VCA figures and are the only figures manufacturers are allowed to publicise. VCA admits that they are unrepresentative of what different drivers can expect. And in Germany a manufacturer has been successfully sued because a driver could not achieve the ‘official’ economy figures for his car.