I’d never buy a car with scuffed alloys. So it pains me greatly when I give back a car with damage to the wheels. It smacks of typical motoring journalist – careless in everybody’s car apart from their own.

It wasn’t entirely my fault (it never is!) but I must bare some of the responsibility for the Cayenne’s grazed knees. A head-on meeting in an Edinburgh street that nudged me into the cobbled curb. Ouch.

Annoying as it is, the Porsche’s ‘restyling’ comes nowhere near what happened to a Range Rover I drove to France in the early 1990s. We had four expensive mountain bikes on the roof and the service station canopy was obviously way too low.

Fortunately, I wasn’t driving but it fell to me to call the Land Rover press office and explain myself. The damage was extensive but nobody batted an eyelid. Let’s hope Porsche are as understanding…

It’s impossible to drive up to the gates of Edinburgh Castle at this time of year. Nothing to do with emissions in the ‘old town’, it’s just the mass of meandering tourists cause the council to block the road off.

Despite creeping along in self-righteous electric mode in the E-Hybrid Cayenne, I’ve been forced to turn around and park some distance away from the hotel, The Witchery at the Castle, and catch a taxi in.

It took almost seven hours to get here from Cheltenham – having to turn back with a few hundred yards to go was slightly painful!

The Cayenne averaged just under 30mpg along the M5 and M6 – more proof, if you needed it, that hybrids are less efficient than your average diesel on long distance, high speed drives.

I tweaked between driving modes as much as possible – battery power in the traffic jams and then back to V6 petrol power on the high speed stretches. It didn’t make much difference

I do hope car dealers selling hybrids to less knowledgable customers make it clear that this is the case. And until the official mpg test for hybrids is changed accordingly, I shall keep banging on about it…

The third incarnation of the Cayenne hybrid is the best. It’s not perfect by any means – and whether a battery-backed sporty hybrid will work for you depends very much on where and how you use it.

But the previous generation model featured technology that dated fairly quickly. The battery pack could only be recharged via the engine. However, for the first time this one can be plugged in to the mains, taking just 3.5 hours to hit 100 per cent.

It’s modestly quick off the mark, features a ‘standard issue’ Porsche interior (which means you are paying extra for kit that should be standard – like a DAB radio) and can travel 22 miles on electric charge only.

If you like in a city and need a premium brand SUV it’s going to save you a packet. However, for long distance, high-speed motorway hacks a diesel is the cost effective option.

And to prove it, tomorrow I’m going to drive seven hours to Scotland. Any guesses on the mpg? I’ll let you know…