About Greg’s Petroleum Service, Inc

Based in Delano, California, Greg's Petroleum Service Inc. is a family owned and operated petroleum distributor. Since opening in 1961, our commitment to customer service, reliability, and safety has set us apart. Greg’s Petroleum serves retail, agriculture, oil field, industrial, fleet, and government accounts throughout the San Joaquin Valley and beyond. We pride ourselves on supplying advanced petroleum products while continuing to value customer relationships as highly as we did over 50 years ago.

Greg's Petroleum provides:

Reliable, on-time deliveries

Diligent focus on safety

Wide selection of high performing lubricants and fuel

After hours and weekend deliveries to keep your business moving

Solutions that add value to your business

Over 50 years of industry experience

Our Management

Ron Mariani
President & CEO

Ron first came to work for his father-in-law at Greg’s Petroleum as a fuel driver in 1979, and worked his way up to President of the company by 1990. He has always had a deep appreciation for doing things the right way, and over the years that sentiment has helped bring Greg’s Petroleum to where it is today. When he is not working, Ron enjoys spending time with his family (especially his grandkids), hunting, and fishing.

Kelvin Gregory
Sales Manager

Kelvin is proud to carry on the legacy his father, the late Harold Gregory, started in 1961. With over 23 years of experience, Kelvin is responsible for managing the Greg’s Petroleum sales team, and enjoys working with customers and learning about their businesses. Kelvin has always built business relationships based on honesty, integrity, and standing behind his word. In his time away from the office, you’ll likely find him fly fishing, cooking, or playing music.

Chris Gregory
Oil Operations Manager

Chris oversees personnel, inventory and dispatching within the lubricants division of Greg’s Petroleum. As Kelvin’s son, he feels a strong responsibility to continue to carry the business into the future. He has worked for the company for over 20 years as a driver and salesman, and now uses that broad perspective to guide the lubricants team to success. Outside of work, he enjoys watching hockey, visiting his kids at college, and bowling.

Bob Harris
Fuel Operations Manager

Bob has been in charge of fuel dispatching at Greg’s Petroleum for 4 years, and had 10 years of experience dispatching before that. He excels at the daily challenge of making sure we deliver the right products on time and efficiently. When he is not applying his logistical skills for Greg’s Petroleum, you can find him on weekend trips, catching up on sporting events, and spending time with his family.

Greg Mariani
Marketing Manager

Greg, Ron’s son, worked summers at Greg’s Petroleum growing up before graduating from UCLA and spending 5 years working in the tech industry. He is now back at Greg’s Petroleum and is responsible for marketing and promotions. Greg is excited about improving customer relationships and helping the company expand. Off hours, you will find Greg playing or watching basketball, traveling, and spending time with his wife.

Jordan Fitch
Assistant Oil Operations Manager

Jordan enjoys ensuring Greg’s Petroleum has organized warehouses and appropriate inventory levels. But more than anything else, he loves working with the close-knit team of warehouse personnel, drivers and salespeople. Customer satisfaction energizes him day in and day out. In his spare time, you’ll find him behind a book, teaching the Bible, playing hockey, or spending time with his wife and dog.