Optimal Lube Oil Temperature
Posted by Charles from Carlsbad, NM, US on August 9, 2007
Mr. Goodier:
Given the increased thermal loads from emissions equipment and various other sources, what is considered to be the optimal operating temperature (range) for today’s mineral based oils? Synthetic lubricating oils? Automatic Transmission Fluids? Manual Transmission Lubes? Rear End (Hypoid) Lubes?
Thank you.
CFF
This is an interesting question, as you point out thermal loads of equipment have increased, not just because of the increase in engine outputs, but also the emissions equipemt that is being equipped is increasing thermal load.
The isue is that the ideal temperature range of fluids has not changed, so it is an ongoing battle of OEMs to ensure that their designs do not increase the temperatures further, hence the increasing number of cooling matrices on a modern vehicle.
The IDEAL temperature for a fluid is set by the temperature in which the antiwear and oxidatant additives become active, too cool and these reain dormant, too hot and they do not perform adequately, this is in the ares of 75 - 120C. The other are for consideration is the performance of the base oil itself, Synthetics and partil synthetic handel hot temperatures far better than minerals, so for temperatures above 90C for prolonged times then a synthetic makes more sense.This is an interesting question, as you point out thermal loads of equipment have increased, not just because of the increase in engine outputs, but also the emissions equipment that is being equipped is increasing thermal load.
The issue is that the ideal temperature range of fluids has not changed, so it is an ongoing battle of OEMs to ensure that their designs do not increase the temperatures further, hence the increasing number of cooling matrices on a modern vehicle.
The IDEAL temperature for a fluid is set by the temperature in which the antiwear and oxidant additives become active, too cool and these remain dormant, too hot and they do not perform adequately, this is in the area of 75 - 120C. The other are for consideration is the performance of the base oil itself, Synthetics and partial synthetic handle hot temperatures far better than minerals, so for temperatures above 90C for prolonged times then a synthetic makes more sense.
