First, let’s get rid of a myth: there is no such thing as cheap fuel in Italy. As of August 2017, average prices are €1.45 for gas and €1.25 for diesel, making Italy relatively expensive by comparison to its neighbouring countries. It is possible however to minimise the cost of filling up your tank if you follow a few simple rules.
Fill up your tank before entering Italy
Unless you are renting your car directly from Italy, chances are you are driving in from Austria, Switzerland, Slovenia or France. In all these countries, fuel is cheaper than in Italy. For example, in Austria you pay only €1.20 for gas and €1 for diesel. As an exception to this rule, diesel is more expensive in Switzerland than in Italy though. So stop before the border and fill up your tank. This will save you some money at least for the first few hundreds of kilometres. Be aware though that these low prices are mostly applicable at gas stations away from the highways. It is best to use Google Maps or your GPS device to search for a gas station close to the border, but not on the highway.
Avoid buying fuel on the highways
As in most countries, gas and diesel are significantly more expensive at the gas stations on the highways. For example, while the average gas price is €1.45, it can cost as much as €1.90 on the highways. Either use your GPS device to find a gas station close to a highway, but not right next to it, or simply exit the highway and drive a few kilometres towards a bigger town and you will see the price difference.
Read the electronic price announcements on highways
Most highways have electronic signs announcing the fuel prices for the next few gas stations. The prices are updated in real time and the differences are sometimes quite huge. Pick the gas station that has the lowest prices and drive there in order to save some money.
Use the gas stations at supermarkets
Some large supermarkets or shopping malls have their own gas stations, where the prices are significantly lower. If you are close to such a supermarket or if you have to do some shopping anyway, spend a few minutes to fill up your tank there.