Save Money and the Environment

Converting to CNG will cut your fuel bill by up to 50%! Not only will you have this savings but you will be reducing harmful greenhouse gases too!

Quick Installs

We know your vehicle is a necessary part of your daily function therefore we guarantee to have your vehicle back to you in a quick, timely manner.

Certified Technicians

Our technicians are State of Oklahoma Certified and have performed many installations. You know that your vehicle is in good hands with mechanics you can trust.

Best of Oklahoma

Gratec conversion shop uses only premium grade systems and components for your vehicle conversion. We have been named one of Oklahoma’s best conversion centers.

Gratec Conversion Shop

Gasoline Bi-Fuel Conversions

  • CNG or LPG conversion
  • Premium Fully Automatic System
  • Works with all gasoline engines
  • Gratec Sequential System
  • Versus Gas USA System
  • IMPCO EPA Certified Systems

Diesel Dual-Fuel Conversions

  • CNG or LPG conversion
  • Premium System
  • Average 60% diesel displacement with CNG
  • Average 45% diesel displacement with LPG
  • Engine Safe – EGT sensor monitored
  • Gratec Advanced Diesel Dual Fuel Systems

Conversion Shop

  • CNG or LPG conversions
  • CNG/LPG vehicle repair & Service
  • CNG/LPG maintenance
  • State of Oklahoma Certified
  • IMPCO Certified
  • Fleet maintenance, service & repair



Customized Fleet Solutions

Our team of highly trained technicians can take on any number of fleet vehicles and get them back to you in a timely manner. When converting with Gratec know you can have the peace of mind it will be done right the first time. Does your company switch vehicles often? No problem. Gratec’s installed systems can be easily removed and installed on the next vehicle you purchase!

Best Pricing

Gratec already offers the most competitive pricing in Oklahoma however further discounts are available for our fleet customers!

Service & Maintenance Plans Available

Gratec is now offering service and maintenance plans to keep your CNG vehicle on the road and saving you money.  Our maintenance plan sends you reminders when your vehicle is ready for its next service time guaranteeing the long lasting of your conversion system.


No matter what engine you have we have a solution for you. Whether it is a gasoline or diesel engine we have your solution. With our wide variety of tanks we can complete an installation staying under any budget. Our shop installs both EPA certified kits as well as non-EPA conversion systems.


Gratec Conversion shop has many happy customers throughout Oklahoma, Arkansas, Missouri, Kansas, Louisiana, Texas, California and many more! Gratec has a customer satisfaction guarantee and a name you can trust! We work with individuals as well as companies of all sizes.


Gratec’s shop and technicians are both Oklahoma Certified which will qualify your vehicle conversion for the 50% state tax rebate! This means that the state of Oklahoma will cover 50% of your invoice cost from Gratec for converting your vehicle to a CNG vehicle.

Schedule your Appointment Today!!
Contact us to schedule your conversion, repair or service appointment today! Contact Us!