I see adds all the time with oil companies toting the cleanliness of their full synthetic motor oils. And yes it is true they can run longer before sludge formation sets in. However, I a do not believe that they work effectively in dissolving sludge deposits that are already in place. I was just looking at an M1 advertizement showing the tear down of a Mercedes motor that had been run for 1,000,000 KM, with oil changes at 13,000 KM. On the surface it looks impressive. However, the motor was new to start and the miles or kilometers were achieved on a chasis dino. I am not so sure that a chasis dino is representative of real world driving. For one it was a very controlled envirnment. And secondly I am quite sure they did some prior testing to be sure that the oil would hold up over 13,000 KM oil change intervals before starting the test. And my other oservation was that the parts from the tear down, although not sludged, had a fairly hefty amount of staining, which some folks might see as varnish.
On the same ad they showed a 2009 Chysler Sebring that had some minor sludging. And after switching to M1 the engine was clean in 4000 miles of driving. Yet when I look at the footnote below the pictures it states that the sludge that was originally present was actificial produced and may not represent sludge derived under normal driving conditions. Really makes you wonder.
My opinion is that yes full synthetic can run longer and resist contamination longer. But that is mainly due to engineered molecules that don't require the same level of additives as does a conventional oil. And that the synthetics are better at dissipating or carrying away heat from frictional areas and thus help the motor run a bit cooler. But with regards to dissolving sludge that is already in place, I don't think any of them do any heavy lifting cleaning of engine deposits already in place. I haven't seen any real world customer motors to make me believe so.
-- Edited by Frank on Sunday 21st of April 2013 09:24:31 AM
