Quote:
Originally Posted by Bror Jace
For those of you skimping on oil changes, the coefficient of friction of the oil goes up as contaminants accumulate and the additive package becomes depleted. As friction goes up, heat and drag increases ... reducing efficiency. The pennies you save will cost you over the road.
I'm with The Mullet. Change your oil and use good supplies when you do.  |
Sorry to steer the thread in an other direction, but I'd just like to mention a way to know if you need to change your oil (appart from an oil analysis).
All you need is an oil pressure gauge and oil temp gauge.
When you change your oil with fresh oil, record the pressure at idle for a given temperature (fully warmed engine).
Later in time, as long as the pressure at the same rpm and temperature remains the same you don't need to change your oil.
As Bror mentionned, as the oil age, accumulate dirt and contaminants and additives get depleted, the viscosity of the oil will change. You can detect the change of viscosity by monitoring the pressure of the oil under the same flow (rpm) and temperature.