2012 Nissan X-TRAIL Pricing and Specs

Changing the fuel filter may affect fuel economy indirectly, but not to the extent of dropping consumption 3.5 litres per 100km. The indirect effect we’re talking about here is having an engine with a clean filter that is making all the power it possibly can, and that, in turn, allowing you to drive it with less throttle input and, therefore, lower fuel consumption. But the end result would be fractions of a litre per 100km.

A camshaft-angle sensor, I think, would be in much the same boat. By having the camshaft timing perfectly spot on, you’ll have an engine that’s making the most of each litre of fuel. But, unless the current cam-angle sensor is faulty, changing it for a new one won’t make a scrap of difference to your fuel economy.

The best way to reduce your fuel usage is by driving the vehicle smoothly and gently and with a light right foot. My suspicion is that that’s exactly what you’ve been (sub-consciously) doing since changing the fuel filter and chasing better fuel mileage.

The clock-spring is the electrical linkage that connects the driver’s air-bag and everything else that lives on the steering wheel (cruise-control, stereo controls and more in a modern vehicle) with the rest of the car. The clock-spring is needed to allow the steering wheel to turn while maintaining those electrical contacts.

It’s quite a common thing to have to replace and will probably cost a few hundred dollars to have a workshop do the job.

The obvious benefit is fuel economy, the diesel is much more economical than the equivalent petrol model. On average the diesel consumes 20 per cent less fuel than the petrol model. The other possible benefit is that the diesel has an automatic transmission whereas the petrol has a CVT transmission.