RTL News did a math: according to the news site, it can even be financially worthwhile to refuel in Belgium, if you live 120 kilometers from a Belgian gas station.
Refueling in Belgium
In the calculation goes RTL News based on the most common car in the Netherlands, which is a Volkswagen Golf with an average year of construction, namely 2011. This car drives 1 in 16 and therefore has a petrol tank of 55 liters. The recommended retail price for petrol in Belgium is currently 1.95, but the excise duty reduction will still start from that. As a result, a full tank in Belgium costs just under 100 euros: 97.68.
15 liters ‘free’
Prices are higher in the Netherlands. Here the suggested retail price is currently 2.43 per litre. This means that for the same amount you get a lot less petrol here, namely only about 40 liters. So if you fill up your Golf in Belgium, you get almost 15 liters ‘free’. With this you can drive a total of about 240 kilometers, so about 120 kilometers back and forth. If you drive a diesel, you have slightly less advantage, because diesel is quite expensive in Belgium. It saves about 100 kilometers each way.
Source: RTL News