The GM Engine Oil Life System (EOLS) is now a global application. (Fig. 10) With the dexos specification in place for all GM cars and trucks, GM will be able to recalibrate the EOLS computer algorithm to further extend service intervals on all vehicles.
Fig. 10
With the introduction of GF-4 in 2004, the EOLS was recalibrated based on the longer service intervals that were made possible by the tougher enhancement of the oils meeting the GF-4 standard.
The optimum service intervals determined by the EOLS are based on engine speed, ambient air and engine temperatures, engine running time, and other factors. As oil ages in an engine, fuel economy decreases. Friction modifiers and other additives become depleted, leaving oil to thicken due to oxidation and accumulation of soot. This affects engine protection properties as well as fuel economy.
When the EOLS determines that an oil and filter change is needed, the driver is notified by a Change Oil message on the instrument panel. The oil change should be performed within 600 miles (1,000 km).
TIP: The EOLS must be manually reset when the oil is changed.
- Thanks to Matt Snider and Eric Johnson
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