Diesel cars are a popular choice for many car rental users with hire cars in this range boasting excellent fuel economy as well as being a greener more environmentally friendlier options against the petrol engine counterparts. At Faro airport you can find many guaranteed diesel engined hire cars available through a host of different suppliers, so use the filter or look out for the diesel flag shown on the top left of the picture on the car select screen, step two of the booking process.
A consideration though when choosing a diesel car is the fuel policy of the supplier offering said hire car. If they operate a full to empty fuel policy and your rental is a short one, then the possibility of using a full tank is less than the chances of using the full tank on a petrol model due to the increased fuel economy.
In Portugal and unlike the UK say the cost of diesel at the pumps is considerably cheaper than petrol per litre with costs for a litre of diesel coming in at around €1.49 as opposed to €1.70 for unleaded petrol. With the increased fuel economy afforded by a diesel car, if you are intending on a lot of driving on your trip then a diesel car would be the cheaper alternative. As a guide but not a rule, diesel models can be more expensive to hire than the petrol alternative model so consider the total price including the fuel you will use when choosing the right car for you.