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Like many other products Costco sells, the company is able to squeeze price margins on gasoline thanks to the scale of its operations. While it may not always offer the very lowest prices available within your car’s range, the cost is likely to be close enough to make going anywhere else feel foolish. That makes its gas stations an attractive option for customers who are already driving to one of its locations to load up on food in bulk, furniture, or unexpected tech products sold at Costco.

If its gas stations are one of the Costco perks you’re missing out on, they can be a bit of a gauntlet for the uninitiated. Lines at many locations can stretch back through the parking lot, giving some shoppers the impression that the process is anything but quick. Once you get to the front of the line, you’ll notice that things work a bit differently at Costco compared to the Conoco or Shell down the street. But don’t be intimidated. Once you’re accustomed to the ins and outs of the process, you’ll be fueled up on the cheap and on your way in no time. To that end, I’ve compiled a few of the most important things you should know before you head to the nearest Costco gas station.

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Most gas stations take a rather laissez-faire attitude toward access to the pumps. It’s first-come, first-served, and anyone can nab an open pump if they can get their car to it. At Costco, things work a bit differently. Lines form in a single file to create a one-way flow of traffic. Cars line up for the pumps on one end of the canopy and exit on the other. At most Costco locations with a gas station, you’ll see signs in the parking lot directing you to the correct side to enter.

Costco claims this system allows for the same sort of “high volume and low prices” available in its warehouses. Sure enough, lines at its gas stations may look a mile long at times, but you’ll often be surprised at how quickly they move. As long as you follow the rules and pay attention to the flow of traffic, you’ll most likely be gassed up and on your way home before too long. If you’re unsure which side of the pumps to enter from, which can be especially confusing if there’s no line, look for the arrows on the ground that point the way forward. There may also be signage nearby to help direct you.

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You’re probably accustomed to filling up your gas tank by aligning the side of your car it’s on with the pump. At Costco, this can create lopsided lines, with customers trying to ensure an easy fill experience. However, if you’re in a hurry, you don’t need to worry about which side of your car the gas tank is on. Costco’s pumps are outfitted with high-reach, extra-long hoses that can accommodate your tank, even if it’s on the furthest side of your vehicle from the pump.

According to the wholesaler, every Costco gas station is equipped with those more accommodating hoses, and we haven’t found an exception to the rule. Sure enough, the hoses at my local Costco gas pumps can easily accommodate the passenger side tank on my Subaru Crosstrek, even if I pull up to a pump on my driver’s side.

Even better, now that you know about Costco’s high-reach hoses, you can use that knowledge to gain an advantage over people who haven’t figured it out yet. One of the common mistakes people make when shopping at Costco is to enter a long line ahead of the pump, even when there’s a much shorter line available. They might do this because they’re under the false impression that they need to orient their vehicle’s gas tank with the pump. No need to correct them. In fact, you should be thankful to them, since their lack of knowledge helps to ensure that queues remain uneven. With everyone packed into one line of traffic, you’re free to choose the shorter line for yourself.

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Lines at Costco gas stations can get long enough to make your eyes glaze over, but you can help keep things moving efficiently by knowing when it’s your turn in line. When you pull up to the front, you’ll notice that there are two or more pumps in each row. That’s because the system is designed to accommodate more than one vehicle at a time, depending on the location. If the car in front of you is filling up at the pump directly in front of you, but there’s an open pump in front of them, you should pull around them to park at an open pump and begin fueling.

As cars file in a single line toward the pumps, there’s another lane specifically for this purpose. It is meant for pulling around other cars to get to the next available pump. You should only use this extra lane for that purpose. Do not make the mistake of using it to get in line for the pumps, as you will inconvenience other drivers and slow the entire line down.

Unfortunately, it seems as though many Costco members are unaware that they can pull ahead of the car in front of them to an open pump. This results in situations where there is an open pump at the front, but the person in front of you remains in line. In these situations, it’s hard to know how to respond. Honking could be seen as aggressive, and it doesn’t tell the person holding up traffic what they’re doing wrong. You could simply pull around and take the pump yourself, but that might be seen as rude. There’s no clear way of dealing with the situation.

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Because the majority of people who get their gas at Costco are filling up their tanks before or after a grocery trip, the pumps are normally at their busiest when the store is open. However, many Costco gas stations open before the store does and stay open later, too. That means early morning or late evening is often the best time to get gas at Costco, assuming you don’t need anything from the warehouse. You shouldn’t generally worry about going at odd hours, given that Costco goes above and beyond to prevent card skimmers and other issues at its pumps.

If going for gas extremely early in the morning isn’t your cup of tea, or if you want to be able to shop while you’re there, you could consider adjusting your Costco membership. Although Gold Star and Business members can shop during normal hours beginning at 10:00 a.m., Executive members get to shop starting an hour earlier at 9:00, giving you time to gas up and get your supplies while the store is still relatively deserted. 

It can also be helpful to visit different Costco locations in your area to get a sense of which ones are the least trafficked. If driving an extra five minutes saves you six minutes in line at the pump, that’s time saved. Additionally, if you live near one of the somewhat rare Business Center locations that also have a gas station, those are known to see relatively low traffic compared to a normal Costco. All members can shop at Business Centers, so don’t be intimidated by the name.

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If you drive a diesel fuel vehicle, Costco can be a fantastic and cost-saving place to fill up your tank. However, not all Costco gas stations have diesel fuel available, and you’ll waste a significant amount of time if you visit the wrong one. But you don’t have to haul your truck across town in search of a Costco with a diesel pump. The Costco app or website will thankfully provide that information in just a few seconds, so you can travel with confidence. The website and app both show gas prices at each location, too, allowing you to make an informed decision before you make the drive over. Prices are listed for all fuel types.

To find gas and diesel info and pricing using the app, tap the Warehouse tab at the bottom of the screen, then tap Warehouse Locator. To check normal fuel prices, tap Filter, then check the box for gas and tap Apply. You will see a map showing only the warehouses with gas stations. Tap on each of them to see prices for normal and premium fuel. To check which locations have diesel, follow the same steps, but check the box for diesel instead of gas, then tap Apply. Tap on any of the diesel locations displayed on the map to quickly see prices for all fuels at that location, including diesel.

On the website, hover your mouse over the Locations tab near the top of the site, then click Gasoline. On the next page, click Gas Station Locations. Click on any location to see pricing and available services. For diesel, go to the Gasoline Diesel page, where a full list of diesel locations is available.