Issue link: https://read.dmtmag.com/i/59415
heat into the coolant. Should even a thin layer of scale coat those pipes, oil temperature would rise. The oil cooler can bring temperatures down from about 300 degrees to close to 200 before releasing it into the pan. Without it, oil would decompose quickly during sustained engine operation. "It's all about maintaining the optimum operating temperature, which will reduce the thermal stresses and oxidation rate of the oil," says Rob Banas, commercial vehicle lubricants application engineer with ExxonMobil. "If the engine temperature is higher, the oil degradation rate will be higher," says Dan Arcy, Shell Lubricants OEM technical manager. "Glance at the oil temperature gauge every now and then." Arcy also suggests keeping an eye on the coolant temperature gauge and performing maintenance such as flushing out bugs and debris that have clogged radiator fins to keep engine temperature at the optimum level. "Other areas of oil stress include allowing impurities such as antifreeze, fuel, or dust in. If you find your coolant level is changing, this should be a red flag" for system problems, says Gambill. An external leak is less problematic than an internal one, where coolant will mix with the oil, react chemically and interfere with The heat exchanger under the two turbochargers is the oil cooler. Keeping the cooling system clean pre- vents scale in the oil cooler, too, and this means the oil stays cooler and can resist oxidation much longer. the oil's performance. Maintaining coolant level maximizes the performance of the radiator by increasing the surface available for heat to be transferred to outside air, Gambill says. You need to keep the system full and properly protected from corrosion by using ELC or with Supplemental Coolant Additives to prevent scale that traps heat. Arcy also says coolant should not run at too low a temperature. This happens because of a failed thermostat. Cold running causes poor combustion and fuel dilution. Also keep the oil pan full. "If it's Get routine oil analysis New engines exhibit levels of contaminants that remain from initial construction of the radiator, oil cooler and EGR cooler. So even when an engine is relatively new, oil analysis is important for proper maintenance, says ExxonMobil's Rob Banas. Knowing not only the miles on the oil, but the total hours the engine has run, is critical to knowing whether a contaminant is coming in from outside and likely to cause damage. If you buy oil from an oil supplier and consistently use the same brand, it's possible the oil refiner will offer free oil analysis. If not, ask your supplier or engine dealer for information on a reputable lab. A good analysis report will cost $30 to $50. Analysis should be performed at every drain if using extended intervals. OIL COSTS $250 for 11 gallons 15,000-mile changes 25,000-mile changes Savings $250 x 66.6 = $16,650 $250 x 40 = $10,000 $6,650 FILTERS COSTS $22 for OEM bypass oil filter $22 x 66.6 = $1,465 40 x $22 = $880 $585 DISPOSAL COSTS $20 per change $20 x 66.6 = $1,332 $20 x 40 = $800 $532 TOTAL SAVINGS OF NEARLY $8,000 over the million-mile life cycle of an engine are possible on oil, filter and disposal costs alone when drains are extended from 15,000 miles to 25,000 miles. 36 OVERDRIVE APRIL 2012 Extend oil life