When a new oil is being developed it is not until it has been trialled in the real world and in realistic conditions that its effectiveness is proven and this is particularly true when talking about pushing out the oil drains. The latest Vecton formula from Castrol has been running with Gilbert’s Transport Service across Central Australia and AHG Refrigerated Logistics on long remote haul routes.
Body//New oil technology is making it possible to extend all oil drains out too much longer distances. However, when a task is heavy and distances are long it is important to make sure the oil in the engine will retain its integrity well past the proposed 80,000 km oil drain limit.
The process of engine development continues apace, as elsewhere in the world, exhaust gas emission limits continue to reduce in areas like North America, Japan and Europe, as well as growing economies like China’s. As with all of this new technology it creates issues for other component suppliers.
One of the major components in any diesel engine is its oil. It is the component which helps improve engine efficiency and longevity and one which it is vital to get right on the part of the operator of the truck.
We are seeing Euro-6 and US EPA exhaust emission rules continue to further constrain NOx, particulates emissions and, now, carbon dioxide emissions. The parameters within which any engine must perform become tighter and tighter. This means the design of the engine oil also has to live within tighter parameters.
This was certainly the case for Castrol in the development of their Vecton Long drain CK-4/E9 oil for the next generation of engines. The new oil needed to meet the API CJ-4 standard as well as pass a couple of aeration and oxidation tests from Caterpillar and Volvo.
Pushing Out the Oil Drains in the Real World
In introducing this oil into Australia, the harsher and heavier conditions we endure have meant any new oil has to undergo some stringent testing. This is to ensure the performance specified still works when trucks are running at masses up to 140 tonnes and at a much higher fuel burn rate than is the case in the US or in Europe.
As part of the new oil’s introduction into Australia, the CK-4 oil was tested with two fleets. Gilberts Transport Service runs triple road trains up and down the Stuart Highway from Adelaide to Darwin in round trips up to 7,000km. AHG Refrigerated Logistics have a number of regular runs in remote areas also handling road train work in tough hot conditions.
“Our main run is up to Darwin with the heat the big killer, regularly hitting 45 to 50 degrees into the Territory,” says Peter Gilbert, Managing Director Gilbert’s Transport Service. “We’ve relied on Castrol engine oils to help manage this for over 20 years, so when they suggested we test their new Castrol Vecton Long Drain we were happy to help. We started with 20,000km drain intervals but soon saw we could push it further, to over 35,000km. So we get six Darwin return runs between drains, and the longer intervals mean maintenance savings and easier scheduling.”
The 18 month testing period saw Castrol work with these two fleets, selected for the severe conditions under which their trucks worked, in terms of masses, ambient temperatures and distances covered. 24 trucks were involved with a broad selection of engine manufacturers, all running in remote areas.
“Our fleet travels over some of the toughest tracks in the country, so when Castrol asked us to test a new diesel engine oil, we had no hesitation in taking part,” says Glen Stephan, National Fleet Manager, AHG Refrigerated Logistics. “We were able to achieve 80,000km oil drains compared to 60,000kms with our previous oil. As a result, we’ve gone up on oil drains, while service costs, down time and cost per kilometre are down.”
Oil drain intervals were extended out to 80,000km to see how the oil stood up to these tough conditions. Extensive oil sampling was used to keep a sharp eye on the key indicators of oil integrity. These are Total Base Number, Total Acid Number, Kinematic Viscosity, soot and various metal levels, and they give an indication to researchers about the oil’s progress in terms of oxidation, viscosity, aeration and wear.
Testing showed the acid build up in the oil was kept down to a level avoiding corrosive wear of engine parts. The Total Acid Number (TAN) remained constant for the full distance and well below the OEM recommended limit. The Total Base Number, which indicates the level of ingredients used to reduce acidity, showed a steady decline over 80,000km, but was still well above the necessary level at triple the TAN level before the next oil change.
Over time, soot and sludge can thicken oil or mechanical shear can thin the oil, reducing viscosity. In the trial the viscosity level held steady over the whole 80,000km, rising slightly over the period. Testing also looks for traces of metals, through engine wear. Iron, copper and lead levels did increase over the oil drain period, but at such a low level as to remain far below the recommended limit.
“As part of the team that tested Castrol Vecton, I was amazed at the results,” says Greg Schubert, a test driver on behalf of Scott’s Refrigerated Logistics. “We used to get 60,000km drain intervals, but now it’s out to 80,000kms. During the test, the oil was sampled every 5,000kms, and the results were fantastic. In fact, while 80,000kms is our new benchmark, we know that the oil will stand up for far longer. It means truck down time and cost per kilometre are both reduced.”
Setting the Standard
The standards for new oil are set by the American Oil Institute (API) which has become the recognised authority for the development of petroleum, natural gas and petrochemical equipment and operating standards.
API Service Category CK-4 specifies oils especially effective at sustaining emission control system durability where particulate filters and other advanced after treatment systems are used. The standard concentrates on protection against oil oxidation, viscosity loss due to shear, and oil aeration. The oils also have to be backwards compatible with older engines. Castrol claim the new Vecton CK-4 exceeds the requirements of oil performance to meet this standard by 42 per cent.