Quick Answer: Not all Costco gas stations offer diesel fuel—availability varies by location. As of October 2025, diesel is available at select Costco locations across Arizona, California, Colorado, Hawaii, Idaho, Nevada, Oregon, Washington, and other states. Use our Costco Diesel Station Locator to find stations with diesel near you, including current prices updated multiple times daily. Diesel typically costs $0.20-$0.40 more per gallon than regular gas but offers 45-55 cents savings versus competitor diesel prices.

Why Diesel Drivers Choose Costco

Costco has built a strong reputation among diesel vehicle owners for providing high-quality fuel at competitive prices. RV owners, truck drivers, and commercial fleet operators particularly value Costco’s Kirkland Signature Diesel, which meets TOP TIER™ performance standards.

Diesel fuel efficiency makes it attractive for heavy vehicles and long-distance travel. The added cost per gallon compared to regular gasoline pays off through better mileage and engine longevity. Costco’s commitment to fuel quality ensures your diesel engine runs cleaner and more efficiently.

As a Costco member, you access diesel prices averaging 45-55 cents below traditional truck stops and gas stations. For commercial drivers and RV enthusiasts covering thousands of miles annually, these savings add up significantly.

Finding Costco Diesel Stations Near You

Locating diesel at Costco requires checking availability before you visit. Unlike regular gasoline, which nearly all Costco gas stations offer, diesel availability varies considerably by region and location.

Best Search Methods:

• Use Our Diesel Locator: Our specialized diesel station finder shows current prices and confirms availability at all Costco diesel locations nationwide
• Check the Costco App: The official app indicates which stations offer diesel fuel service
• Call Ahead: Contact your local Costco gas station directly to verify diesel availability
• Look for Pump Signage: Diesel pumps are clearly marked at stations that offer this fuel type

Availability can change over time. Some locations have discontinued diesel service in recent years based on local demand patterns. Always verify before making a special trip, especially when traveling to unfamiliar areas.

Diesel Availability by State and Region

Costco offers diesel at select locations across the United States. Regional availability reflects local demand from commercial drivers, RV owners, and diesel vehicle operators.

Western States (Strong Availability):

• California: Widespread diesel availability including Fresno, Sacramento, San Diego, and Folsom locations
• Oregon: Multiple stations serve diesel customers in major metro areas
• Washington: Good diesel coverage across the state
• Arizona: Select Phoenix and Tucson area stations
• Nevada: Available at Las Vegas and Reno locations

Mountain and Plains States:

• Colorado: Diesel available at select locations
• Idaho: Limited availability in larger cities
• Utah: Some Salt Lake City area stations offer diesel
• Montana: Select locations including Billings serve diesel customers

Other Regions:

• Hawaii: Select island locations provide diesel service
• Alaska: Limited diesel availability at Anchorage locations
• Texas: Some locations offer diesel, though availability is more limited than western states
• Michigan: Limited diesel coverage in select metro areas
• Missouri: Some locations provide diesel service
• Oklahoma: Select stations offer diesel fuel
• Louisiana: Limited diesel availability

Many Midwest and Eastern states have limited or no diesel availability at Costco locations. This reflects regional fuel preferences and infrastructure decisions.

Featured Costco Diesel Stations Across America

Here are some popular Costco diesel stations serving RV owners, truck drivers, and diesel vehicle operators nationwide. These locations consistently offer competitive diesel pricing and TOP TIER™ quality fuel.

Pacific Northwest:

• Tacoma, Washington – Major I-5 corridor location
• Everett, Washington – Convenient for Seattle-area travelers
• Portland, Oregon – High-traffic metro station
• Bellingham, Washington – Popular with Canadian RV travelers

California Diesel Hubs:

• Visalia, California – Central Valley agricultural region
• Santa Cruz, California – Coastal location
• Oxnard, California – Southern California access
• Rohnert Park, California – North Bay Area

Mountain West Locations:

• Timnath, Colorado – Fort Collins area station
• Sandy, Utah – Salt Lake metro area
• St. George, Utah – Southern Utah gateway
• Billings, Montana – Major Montana hub

Central United States:

• Tulsa, Oklahoma – I-44 corridor location
• Kansas City, Missouri – Major metro station
• Wichita, Kansas – Central Kansas location
• Traverse City, Michigan – Northern Michigan access

View Complete List: These represent just a sample of Costco diesel locations. Browse our complete diesel station directory to find all available diesel stations with current pricing, addresses, and operating hours. The directory includes real-time price updates to help you plan fuel stops during road trips.

Diesel Pricing: What You’ll Pay

Diesel fuel costs more than regular gasoline due to refining processes and federal tax differences. Understanding diesel pricing helps you calculate real savings at Costco.

Typical Price Differences:

• Diesel runs $0.20-$0.40 per gallon above regular unleaded prices
• Costco diesel averages 45-55 cents below competitor diesel prices
• In high-tax states like California, diesel savings can reach 60-70 cents per gallon
• National average diesel prices fluctuate with crude oil markets and seasonal demand

Savings Calculator for Diesel Drivers:
Commercial truck drivers and RV owners see substantial annual savings. Here’s an example:

• Average weekly diesel purchase: 50 gallons (typical semi-truck or large RV)
• Costco savings: 50 gallons × $0.50 = $25 per week
• Monthly savings: $25 × 4.3 weeks = $107.50
• Annual savings: $107.50 × 12 months = $1,290

For fleet operators managing multiple vehicles, these savings multiply significantly. The Costco membership pays for itself within the first week of diesel purchases.

Kirkland Signature Diesel Quality Standards

Costco’s diesel fuel meets rigorous quality standards that protect your engine and optimize performance. All Kirkland Signature Diesel is formulated to deliver consistent results.

Key Quality Features:

• TOP TIER™ Certified: Exceeds minimum EPA detergent requirements
• Deposit Control Additives: Keeps fuel injectors clean for optimal combustion
• Engine Protection: Reduces build-up that can harm diesel engines
• Cold Weather Performance: Formulated for seasonal temperature variations
• Consistent Quality: Regular testing ensures reliability

Clean fuel injectors mean better fuel economy, smoother engine operation, and reduced maintenance costs. Costco’s commitment to fuel quality makes their diesel a smart choice for commercial and recreational diesel users alike.

Who Benefits Most from Costco Diesel

RV Owners:
RV enthusiasts traveling thousands of miles annually save substantially on diesel fuel. The combination of lower prices and high-quality fuel makes Costco a popular stop for RV travelers. Many RVers plan routes around Costco locations for fuel and supplies.

Commercial Truck Drivers:
Independent truckers and small fleet operators maximize profitability through Costco diesel savings. Though not all routes pass convenient Costco locations, drivers who can access their stations see significant cost reductions. Some drivers coordinate loads specifically to refuel at Costco warehouses.

Fleet Operators:
Companies operating diesel vehicle fleets benefit from bulk fuel savings. Fleet card acceptance at some locations makes Costco an attractive fueling option for business diesel needs.

Diesel Car Owners:
Owners of diesel passenger vehicles and light trucks also enjoy Costco’s competitive pricing. Though diesel cars are less common in the U.S., those who drive them appreciate the quality and value Costco provides.

Payment Options for Diesel Purchases

Costco diesel purchases follow the same payment methods as regular gasoline:

• Visa credit and debit cards
• Most PIN debit cards
• Costco Shop Cards
• Mobile payments (Apple Pay, Google Pay) linked to Visa
• Costco Anywhere Visa Card: Earns 4% cashback on diesel purchases (up to $7,000 annually)

The 4% cashback on the Costco Visa card adds another savings layer. On $4.50/gallon diesel, you earn 18 cents per gallon cashback. Combined with Costco’s base discount, total savings can exceed 70 cents per gallon.

Some locations accept commercial fleet cards, though this varies by station. Contact your preferred location to verify fleet card acceptance before relying on it for commercial fuel purchases.

Frequently Asked Questions

Does Costco sell diesel fuel?

Yes, but not at all locations. Diesel availability varies by state and individual warehouse. Use our diesel station locator to find stations offering diesel fuel with current prices.

Which states have the most Costco diesel stations?

California, Oregon, and Washington have the strongest diesel availability. Arizona, Nevada, Colorado, Idaho, Utah, and Montana also offer diesel at select locations. Eastern and Midwest states have more limited availability.

How much does Costco diesel cost compared to regular gas?

Diesel typically costs $0.20-$0.40 more per gallon than regular unleaded gasoline at Costco. However, diesel offers better fuel economy, especially for trucks and RVs, making the higher per-gallon cost worthwhile for diesel vehicle owners.

How much do I save on diesel at Costco?

Costco diesel averages 45-55 cents below competitor prices. In high-cost states like California, savings can reach 60-70 cents per gallon. RV owners filling 50-gallon tanks save $22.50-$35 per fill-up compared to traditional truck stops.

Is Costco diesel good quality?

Yes. Kirkland Signature Diesel meets TOP TIER™ standards with enhanced deposit control additives. It protects fuel injectors and optimizes engine performance, matching or exceeding major brand diesel quality.

Can I use my Costco membership at any diesel station?

Your Costco membership works at any Costco gas station that offers diesel. However, you must verify diesel availability at specific locations before visiting. Not all warehouses provide diesel fuel service.

Why don’t all Costco gas stations have diesel?

Diesel availability depends on local demand, infrastructure costs, and regional fuel preferences. Some locations have discontinued diesel service based on usage patterns. Western states with more RVs and commercial trucks tend to have better diesel availability.

Do I get cashback on Costco diesel purchases?

Yes. The Costco Anywhere Visa Card earns 4% cashback on diesel purchases (first $7,000 annually, then 1%). Executive members also earn 2% back on diesel purchases through their annual reward certificate.

Ready to find Costco diesel stations near you? Use our complete diesel station locator for current prices and confirmed availability at all diesel locations nationwide. Also check our main gas price tracker for regular and premium fuel options. Browse our Costco Guides for more fuel tips and money-saving strategies.