A loss of engine power can be due to many things. Most mechanics will start with a check of the fuel and ignition systems to check for things like dud spark plugs, ignition timing, broken ignition leads and coils and whether or not enough fuel is reaching the engine (worn fuel pump or blocked fuel filter). If all that checks out, then the search will move to mechanical things like the camshaft timing, and whether there’s a leaking engine valve or a vacuum leak somewhere.

The 2.5-litre petrol engine in your X-Trail is a very well known quantity, so there’s plenty of expertise out there. A workshop that deals with Nissans in particular may have seen exactly this problem before and will be able to go straight to the cause.

Meantime, don’t rule out the really obvious stuff like a dragging brake that could be making the vehicle feel sluggish.

The biggest complaint from owners of the earlier X-Trail turbo-diesel was a lack of low-down torque which gave the car a lazy feel when accelerating from rest. Nissan actually issued a Technical Service Bulletin (like a recall, but for a non-safety related issue) to reflash the turbo-diesel’s computer to increase boost pressure at low revs and give the car a livelier feel.

But like many modern turbo-diesels, the X-Trail has also been the victim of Diesel Particulate Filter (DPF) problems where the engine never gets hot enough to cause the DPF to self-regenerate. The bottom line is that if you don’t drive the car at freeway speeds for at least 20 minutes once every few weeks, you could be setting the DPF up to fail. Replacing the DPF is a costly business, too, so make sure that your intended use for the vehicle fits with its mechanical requirements.

A diesel engine is also often more costly to own and maintain thanks to higher-cost, more frequent servicing that can easily offset the diesel’s lower fuel consumption compared with a petrol engine. Urban owners are drifting away from diesel powerplants and back to petrol engines, and that, frankly, makes a lot of sense.

Stick with the respected brands and models like the Suzuki Grand Vitara or Nissan X-Trail. With your budget you should be able get into a 2008/2009 model.