I keep in touch with Steve Bennett at 911 & Porsche World magazine, and we’ve been talking about the Cayenne since I bought it. I’ve run gas-powered Subarus for years, and soon fitted gas to the Cayenne, so Steve was interested in my Cayenne LPG experience.

Steve ran a Citröen Xantia on Liquid Petroleum Gas (LPG) a few years ago, and is familiar with the upsides of a car on gas. I just wrote a quick piece for him on buying the Cayenne and fitting the gas conversion. I took a few pics of the main Cayenne LPG components and they seemed worth sharing here, too. See more of the story in Porsche World next month.

Above is the engine bay showing the injector relays (blue) and the evaporator (silver thing on the left hand side of the engine bay). The install is not super pretty, but who cares when you’re doing the equivalent of 35 mpg on petrol. My November fuel bill was £360, December was £163 on LPG with roughly similar mileage.

This is the dash switch: the red light on top is a gas level gauge, telling me to top up sometime (got 60 or 70 miles left at this), the green light on the bottom shows we’re running on gas. The light on the bottom right would come on if I was on petrol.

This shot shows the gas tank. I had a 50-litre toroidal tank fitted, which filled the wheel well and is level with the boot floor, but will ultimately sit lower in the boot. I’ll drop the floor panel back in (I use a load liner at the minute) and then fit a cylinder tank behind the seat, which should give me a total gas range of almost 400 miles: 750 when you add in the petrol. I get 50 miles more per tank of fuel than a certain track fiend friend of mine does! He strenuously denies this is possible: it always makes me laugh.

The floor of the actual bodyshell will be quite cut about to accomplish this tank drop: easy to sort as best mate Rob Campbell at Racing Restorations is an expert metal fabricator, historic race car builder and Porsche rust repair guy. Most normal owners just use a cylinder tank behind the rear seats and have done with it but, when you’ve got a pet metal guy, you put him to work.

The last pic shows the automatic transmission fluid being changed the other day. That is a whole other story.