Chevron’s new heavy-duty engine oil reduces DPF clogging by 60%, is 15 years in the making

Delo 600 ADF 15W-40

Chevron has announced the release of a new heavy-duty engine oil, a fluid which the company says extends the life of the engine’s Diesel Particulate Filter (DPF) and caps a development process that has spanned more than 15 years.

Current heavy-duty engine oils are formulated up to the API CK-4 limit of 1% sulfated ash, but Chevron Oronite Additive Global Product Manager Teri Crosby said the new Delo 600 ADF is formulated to .4% sulfated ash, reducing the rate of DPF clogging by 60%.

“The global appetite for high-quality base oils is going to continue to grow,” noted Kamala Krishna, manager of process research in downstream technology and services. “More recently we are more focused on areas of improved catalysis.”

The DPF collects upwards of 98% of particulate matter emissions in the form of ash and soot. While the regeneration cycle combusts most of the soot from the DPF, ash is an incombustible material derived from metallic lubricant additives that clogs the DPF over time.

“Ninety percent of the ash that goes into the DPF is from the lubricant,” said Keith Shaw, global manager, OEM technical services and approvals.

The idea for what would become Delo 600 ADF first arose in 2003 Krishna said, and was born from a simple question: “Is it possible to reduce or change the metal additives that causes the ash that clog the [DPF],” she said, noting ash problems were brought on by after treatment equipment pressured by tightening emissions regulations.

Serious development of the new fluid started about two years later.

“Lubricant formulation represents a real balancing act,” said Chevron Senior Engineer Shawn Whitacre, who noted additives that boost engine performance don’t always have a positive impact on emissions.

Ash and soot buildup – aside from causing engine back pressure and excessive regeneration cycles that drag down fuel fuel economy – can boost regeneration temperatures and damage the DPF – a maintenance woe that can come replacement price tag of upwards of $7,000.

“As that ash builds up in the [after treatment] channels, all that really does is create a smaller DPF,” Shaw noted. “That means there’s less room for the soot to pack in and the regeneration cycles happen more often … and as that soot packs in, it may kick regeneration temperatures up another [100-200 degrees], which can damage or crack the DPF.”

Crosby said Chevron’s challenge in reformulating the oil was in taking decades old legacy formulating platforms, removing metallic parts of the formula and replacing them with non-metallic components while not degrading the fluid’s protection and wear properties.

Delo 600 ADF 10W-30

“The thing that we wanted to do is to do more with less,” said Willem van Dam, manager of product development. “We went through a number of different iterations … and we determined where the problem was. We moved closer and closer to a product that actually worked for all the different performance aspects of the engine.”

Shaw said over the last two years, OEMs have put more than $5 million into testing the product because they see Delo 600 ADF as a path to improve engine emissions without having to increase the size of the DPF package or re-engineer it.

“This is where a fluid can actually influence future design and the maintenance work they’re going to have to do,” Shaw said.

Chevron’s field testing of Delo 600 ADF kicked off in 2008 with a Volvo fleet. Testing, van Dam said, reflected a 60% reduction in the amount of ash in the DPF, while levels of calcium and magnesium in the oil dropped and the presence of zinc and phosphorus ash disappeared.

Industrial and Coolants Brand Manager Dan Holdmeyer noted Delo 600 ADF can extend DPF service life by up to 2.5 times, while also providing a 3% fuel economy retention advantage over the life of the equipment.

Delo 600 ADF will be available December 2 in 15W-40 and 10W-30 and meets or exceeds API CK-4 and OEM specifications. James Booth, Chevron’s North American commercial sector manager said Delo would also kick off an online educational campaign around the product, adding initial rollout would begin with large trucking fleets before filtering down to retail and truck stop chains.

Price-wise, Booth said the new blend will slot between Delo’s synthetic blend and fully synthetic lines. Holdmeyer estimated operators of off-highway equipment would see the quickest benefit through fewer regens and higher utilization rates. Trucking fleets would reap those same benefits, he said, but would see the most benefit from the improvement in fuel economy.

Rommel Atienza, global commercial brand manager, noted a formulation similar to Delo 600 ADF is already in use in China with positive results.