At the end of last month, I was filling up at a local gas station, and the numbers were climbing frighteningly before I even finished filling the tank. I stood there for a while looking at the receipt. So this time, I made sure to check the numbers properly.

According to the Weekend Gas Watch released by AAA Hawaii on September 25, the average price for regular gas in Kahului was $5.64 per gallon. That's an increase of 12 cents from the previous week and $1.20 from a year ago.

The problem is, it didn't stop there. In the announcement on October 2, the average price in Kahului rose to $5.71, an additional 7 cents in just one week.

The state average for Hawaii in the same report was $5.62, while the national average was $4.41. Hawaii ranks second in the nation after California, which is at $6.40.

Honestly, seeing a jump of over $1 per gallon in just a year is a number that hits the household budget hard. For a 12-gallon tank, that means I'm spending over $12 more each time I fill up compared to last year.

AAA cited the Middle East conflicts, instability in the Strait of Hormuz, and high crude oil prices as the causes. Typically, prices drop around this time, but this year is going in the opposite direction.

International oil prices are something I can't control. So, I focused on ways to prevent my wallet from leaking money.

The first option is, of course, Costco. The Costco gas station in Kahului on Haleakalā Highway is always known for being one of the cheapest places to fill up on the island.

According to a tracker that shows Costco gas prices, as of October 9, regular gas was $5.359. That's a 70-cent increase from $4.659 on September 10, just a month ago.

This means Costco has also gone up. However, when I compare it to the AAA average in Kahului during the same period, I still think it's a better option.

Just keep in mind to consider the membership fee. If you're only saving on gas once or twice, it might not make sense to pay for a new membership. If you're already a member, it's definitely worth filling up while you're shopping.

The second option is grocery store points. Safeway has been offering gas discounts through its Gas Rewards program with club card points, and there's a gas station at the Ho'okipa Shopping Center.

However, the discount limits and conditions change from time to time, so the information I found varied. Be sure to check the app before filling up to see if you have any rewards and how many gallons they apply to.

The third option is comparison apps. AAA also recommends using the free AAA Mobile app to find nearby gas stations with lower prices.

According to AAA, gas stations located next to highways or in downtown areas tend to be more expensive. Just getting into the habit of filling up in Kahului before heading down to the resort can make a difference.

The fourth option is driving habits. This is my favorite method because it doesn't cost anything.

According to fueleconomy.gov, which is run by the U.S. Department of Energy, rapid acceleration, hard braking, and speeding can reduce fuel economy by 15 to 30 percent on highways and by 10 to 40 percent in stop-and-go traffic. I was surprised by how significant those numbers are.

Idling can also burn 0.25 to 0.5 gallons per hour. That time spent waiting in a parking lot with the air conditioning on is all gas money.

Tire pressure can improve fuel economy by an average of 0.6 percent, and in some cases, up to 3 percent. The reference value is not the maximum on the tire sidewall but the number listed on the driver's door sticker.

The fifth option is to drive less. The Maui Bus charges $2 for a one-way trip on fixed routes based on the county fare schedule, and $4 for a day pass.

Since fare adjustments have been mentioned a few times, it's a good idea to check the current fare with the county transportation department before riding. While it may not be feasible every day, using the bus for specific errands can definitely save on gas.

Finally, try to combine errands. If you can group trips to the post office, grocery store, and pharmacy into one day, it will use less gas than starting the car multiple times for short trips.

I've changed my routine to do my weekly grocery shopping in one trip and finish with a Costco fill-up that day. It's a small habit, but after a month, I noticed a difference in my credit card statement.

I have a lot to say about taxes and the logistics of the island, but I'll save that for another time. I believe it's quicker to change what I can rather than waiting for the government to lower gas prices.

In summary, if you're a Costco member, fill up there, check your grocery rewards, and compare prices using an app.

Also, reduce rapid starts, turn off idling, check tire pressure, and combine errands. If it were me, I would start by changing my driving habits right away. It's free and the effects are immediate.

Gas prices change weekly, so the numbers in this article will soon be outdated. Be sure to check AAA or a price comparison app for the latest prices before heading out to fill up.