Healthplan Spain


Filling up with petrol Is It Cheaper To Have A Full Petrol Tank Or Keep Topping It Up? Expat Tips

With the price of petrol soaring in recent months, it’s only natural that drivers will be looking to save money.

There are many ways to save on fuel costs including loyalty schemes, driving more efficiently and of course, filling the tires with the right amount of air.

These and many others which we will cover below are just a few of the ways, but one question that many motorists ask is whether it is actually cheaper to fill the tank right up or just top it up a little at a time.

How we refuel our vehicles may influence how much fuel we burn which in turn could cost us more or less money.

So what’s cheaper - filling the car right up or just topping up periodically?

Less petrol in the tank means more evaporation (in theory)

Many people believe that filling the tank right up will save us money in the long term, however, this is not necessarily the case.

The basic thinking behind it is that when the fuel tank is half full, there is more air in the tank which means the fuel evaporates faster. The quicker it runs out, the more trips you will need to make to keep filling up.

However, many people will rightfully claim that if the tank is full, the car is heavier meaning that it requires more fuel to move it. Although there is some truth to this, the extra cost is very small.

There is of course no harm in lightening the load where possible and only transport items you need as this will burn less fuel.

However, the truth to our burning question is that a full tank only accounts for around 5% of the car's total weight. By reducing your tank to half its maximum level, it means you will only save around 2.5% in total weight. This will give you only a very small saving in terms of fuel economy.

Regardless, It is still recommended that you fill the tank up to the top when you visit the petrol station as this will ultimately save you time as you won’t need to make so many trips.

For example, if you fill the tank up and this lasts a month, that’s just one trip. If you top up periodically, you could make three or four visits over the month costing you time. And you know what they say? Time is money!

Ultimately, the difference you save in terms of the weight of the tank is minuscule compared to the amount of time you will save and the mileage of filling up each time.

Instead of worrying about how much petrol you should be putting in, there are better ways that we have listed below which will have a greater impact and make your fuel last longer.

Other ways to save on petrol costs

  • Tyre pressures - Something that many of us forget to check regularly is that our tyres are inflated correctly. Tyres that are underinflated create more drag which in turn uses more petrol.
  • Turn the air-con (and heating) off - With the summer temperatures currently soaring, you may want to think hard about this one, however, it is a fact that running the air-con or heating in your vehicle uses more fuel.
  • Drive more efficiently - The more revs you use, the more fuel you will burn. If you drive a manual gearbox, make sure you change gear nice and early and avoid high revs.
  • Lighten the load - Having too much unnecessary weight in your car will cost you money as will roof racks and roof boxes which cause air resistance. Making your vehicle lighter and more streamlined will ultimately save you money.
  • Don’t brake so much - That’s right, by keeping your distance, you brake and accelerate less which means you will ultimately save on fuel.
  • Switch the engine off in traffic - If you find yourself in a nasty spot of traffic, simply turn the engine off and save yourself some money.
  • Car share - This one is dead simple. Why have four separate journeys when you can car share with your work colleagues and share the fuel costs?