High mileage engine requires specific oil

Marcos Thadeu Lobo

Mechanical Engineer Graduated from the State University of Campinas (Unicamp). He currently works as an Associate Consultant at the company QU4TTUOR CONSULTORIA.

High mileage engine

High mileage engine – Diesel Cycle/Otto Cycle 4T internal combustion engines with high mileage suffer natural progressive wear on some parts with operation. As compression rings, oil scraper rings and valve guides and stems wear out, increasing volumes of lubricating oil begin to burn, along with the air + fuel mixture, with increased consumption of lubricating oil.

The passage of combustion gases (blow-by) to the crankcase also occurs, contaminating the lubricating oil, reducing its service life and causing loss of power. Other components that wear out over time are the retainers and gaskets of the crankshaft and valve guides, causing internal and external leaks of lubricating oil.

Figures 1/2 – Passage of gases from the blow-by to the crankcase.

Specific oils for high mileage engines

In order to increase the reliability and availability of internal combustion engines with high mileage, postpone the need for repairs and downtime of mobile equipment and reduce the consumption of lubricating oil, lubricating oils with higher Viscosity Degrees have been formulated (eg SAE 25W- 50; SAE 20W-60; SAE 25W-60) with adequate performance levels (eg API CH-4 or higher; API SL or higher).

Figures 3/4 – Lubricating oils for engines with a long service life.

The lubricating oils formulated for use in four-stroke internal combustion engines with high mileage have in their composition a conditioning agent for seals and gaskets that increases the elasticity of these components, reducing internal and external engine leaks (except in the case of radial cracks where it is necessary component replacement).

With high detergency and dispersion, they prevent the formation of deposits in the piston grooves, valve cover, piston skirt, crankcase, etc. thus increasing the useful life, availability and reliability of mobile equipment.

Figures 5/6 – Lubricating oil with sealant and gasket conditioning agent.

The aforementioned lubricating oils are recommended for use in Diesel 4T cycle internal combustion engines used in mobile equipment with an operating time of more than 20 years and for Otto 4T Cycle internal combustion engines that equip mobile assets with more than 100,000 km in service.

Figures 7/8 – Engines in mobile equipment with time in service over 100,000 km – Otto Cycle 4T or 20 years – Diesel Cycle 4T