How long does it take to get results from diesel fuel testing analysis? When a sample arrives at Research Laboratories, Inc it is logged in the same day, assigned a lab control number, then placed in a queue to be tested. All test packages are completed in the order they are received. Single or individual tests can usually be completed in 1 or 2 days depending on what is requested to be performed and how many other same tests are in the queue. Typically most test packages (summer, winter, and emergency generator/fuel maintenance) can be completed in 3 - 5 days from start to finish at our facility. More time is needed for analysis that is not done in-house. IMPORTANT NOTE: Depending on the volume of testing requests/samples in the queue it can take up to 6 weeks for lab reports to be finalized. Typical busy months are April to May and September thru November. RUSH SERVICE is available for an additional fee in most instances. RUSH SERVICE puts your sample at the head of the queue and will be started as soon as possible. Contact us for specific information. Back To FAQs