Oil analysis and total base number

Oil analysis and total base number

Historically, you’ve probably used total base number (TBN) as a key indicator of the remaining useful oil life in your fleet’s engines. The rule of thumb was to drain oil when the TBN reached one-third of its starting value. But changes in engine design—along with the move to Ultra Low Sulfur Diesel (ULSD) fuels—have decreased both the amount and strength of acids produced in the engine. That resulted in changes in engine oil chemistry leading to a reduction in the value you get from TBN test results.

TBN Test Methods

The most commonly used TBN test for new oils is ASTM D2896. The test uses a very strong acid to identify both “hard” and “soft” TBN, which gives the total alkalinity reserve of the sample.

For used oil samples, most labs prefer ASTM D4739. The test uses a weaker acid, so it doesn’t identify newer ashless (i.e., non-metallic) additives. Because of that, reported TBN values will be lower than ASTM 2896.

The spread in values between these two test methods has tripled since CI-4+ and is double that of CJ-4 leading to a reduction in the value of actively tracking TBN.

The 2018 Service Bulletin from Detroit removed TBN limits entirely from its used oil analysis parameters. Other key engine builders may soon follow Detroit’s lead after noticing the TBN values of used oil are much lower than in the past but without any additional indications of adverse oil conditions.

Beyond TBN

A lot has changed in the last 20 years. Sulfur in diesel fuel has dropped from 500 PPM to a max of 15 PPM. Fewer and weaker acids are found in used oil. Engine designs have evolved. Diesel engine oil chemistry has improved dramatically. Because of these factors, TBN is no longer a relevant measure of remaining oil life.

When analyzing used oil reports, you should always consider the full range of available data. In addition to keeping an eye on wear metals and contaminants, monitor Oxidation/Nitration values (condemning limit between 35 to 40) as a best practice. Pair this number with the viscosity trend to determine when oxidation is on the verge of accelerating.

With changes in oil analysis best practices likely come questions. A good resource to find answers is from the industry experts at the Phillips 66 Lubricants Technical Hotline: 877-445-9198.

This tech tip was provided by Phillips 66.

You May Also Like

Phillips takes two awards at Penske Supplier Conference

Phillips Industries was awarded both the 2023 Best Performing Supplier – Components Award, and the 2023 Best Innovation Supplier Award.

Phillips-two-awards-2024-penske-supplier-conference-600

Phillips Industries received two awards at this year's Penske Supplier Conference, taking home both the 2023 Best Performing Supplier - Components Award and the 2023 Best Innovation Supplier Award.

Penske describes its Best Performing Supplier - Components Award as recognizing consistent quality, reliability, and exceptional service delivery. The Best Innovation Supplier Award highlights Phillips' forward-thinking approach and its ability to drive advancements in the automotive components sector, according to the company.

Freightliner M2, SD Plus Series launch updates its medium-duty truck offering

Freightliner introduced the new Plus Series–enhanced versions of its M2 and SD models, including the M2 106 Plus, M2 112 Plus, 108SD Plus, and 114SD Plus. The enhanced models provide a major update to the interior and electrical systems of the M2 and SD models. The OEM noted that the Plus Series is designed to

Freightliner-MD-SD-Plus-Series-1400
Truck cruise control technology that looks at the road ahead

If you’ve ever visited the Northeast region of the country, you’ve most likely encountered intimidating terrain. The winding roads. The steep hills. The intricate routes that challenge any seasoned driver, and, most recently, advanced cruise control systems that aim to improve fuel efficiency and driver comfort.   Related Articles – Four ways A.I. can help cut

Four ways A.I. can help cut diesel fuel costs

The fluctuation of fuel prices has made it more challenging to operate day-to-day. Drivers get paid by the mile, and, when fuel costs go up, margins shrink, impacting how fleets profit and pay their employees. Intelligent technology can lessen the impact of high prices by improving overall fuel efficiency. Related Articles – New ways to

trucking-technology-hacking
Peterbilt GM Jason Skoog charts today’s truck support, tomorrow’s truck solutions

Peterbilt made headlines recently when it became the first major North American OEM to open orders for an electric truck, the Peterbilt 220EV. In this exclusive interview, Peterbilt General Manager and PACCAR Vice President Jason Skoog details the technology investments that are keeping fleets productive during this year’s trying pandemic and laying the groundwork for

Peterbilt General Manager PACCAR Technology Electric Truck

Other Posts

SAF-Holland to build specialty fifth wheel manufacturing plant

After nearly 50 years and 3 million fifth wheels produced, SAF-HOLLAND will move production from Wylie, TX to the new facility, once complete.

SAF-HOLLAND-TX-fifth-wheel-plant-rendering
Dayton Parts offers new aftermarket products for Freightliner, Mack, Cummins and Hino applications

A new DPF differential pressure sensor, engine oil dipsticks and fuel injector wiring harnesses designed to match OEM spec.

Dayton-parts-releases-2-sensor-dipstick-harnesses
K&M Tire hires new executive vice president

In his new role, Jon Zurcher is expected to work with current leadership to strengthen and build on the company’s strategic plans.

KM-tire-Logo
Why fuel filtration science matters

Fleetguard shares the story of filtration science leading to a biodiesel solution with a seven-time increase in performance.