Amazon is gearing up to launch a new Prime Day event on July 8, but they’re already kicking things off with a host of early deals. While most of these are on Amazon devices, such as Echo voice assistants and Fire tablets, the company is offering a huge discount on fuel.

Between July 3 and July 6, Amazon Prime customers can save $1 per gallon of fuel at more than 7,500 BP, Amoco, or AMPM stations. Customers can get a maximum of 35 gallons, which works out to be a savings of $35.

More: Amazon Prime Members Now Save 10¢ Per Gallon On Gas, EV Charging Perks Coming Soon

Needless to say, this is a huge discount as the national average price for a gallon of gasoline is $3.16. With Prime, that falls to $2.16 for the holiday weekend.

While Prime members typically save ten cents per gallon, the latest promotion is sure to draw plenty of attention. However, if you’ve never used Prime at the pump before, there are a few things you need to know.

In order to get the discount, you need to login on Amazon and link your account to BP’s Earnify rewards program. Users can then find a participating station and fill up, while getting a rather sizable discount. Of course, like most reward programs, users need to enter their phone number or use a linked payment method.

Amazon is using the promotion to highlight the little known Prime benefit, which can save customers an average of $70 per year on fuel. It also underscores their sale, which spans four days and promises “millions of deals across more than 35 categories.”