Quiet Oil--Cause?

Messages
1,634
Location
Southwest
Thread starter
Anyway, I've been pleased with the UOAs I get from Motorcraft synblend and the Quicklane service. But I saw jugs of Castrol Edge EP for cheap at WM and I somewhat impulsively bought it. As we all know, products that come in gold colored jugs are the best. Also, I was hoping I could get a solid years' worth of service out of the oil. The MC would be pretty close to failure at 9K. An extra 3-4K would be good. Anyway, the engine (3.7L Ford) was noticeably quieter with the new oil. I'm about 95% sure it wasn't just my imagination. What causes this? Does this signify that it's lubricating better? I figure unless it's out and out consumer fraud, the Castrol Edge EP ought to make it to 13K, (although I'll UOA) But what makes an oil 'quiet'? About 85K on the unit, in good condition.
 
Last edited:
Messages
1,411
Location
Western Canada
You never said what grade of oil you were / are using. A motor oil grade, say xW30, is a range. One 30 grade oil can be thicker than another 30 grade oil. Both are still 30 grades, but one can be on the thin side of the range, the other the thick side of the range. The thicker one can run a little quieter in the engine. Also, the oil you took out could have thinned out somewhat due to wear / shear / or fuel dilution. The new oil is at the new viscosity spec, and thus thicker, and quieter, for awhile. And, hot oil is much, much thinner than cool oil. Even oil at room temperature ( 70*F) is way thicker than oil at 212*F. If you compare the engine sound with hot, old oil, then you change it out to new, still cool oil, the new oil is way thicker, and usually quieter, at least until it warms up. And sometimes IT IS our imagination ... and that's ok. Your engine won't complain about clean, fresh oil !
 
Messages
1,441
Location
CA
Castrol oils are typically on the thicker side of the range for that grade. And you're also removing an oil that has thinned even more in use.
 
Messages
33,512
Location
Southern NJ
Oil and noise depends on a lot of variables - placebo, base oil type, viscosity, additive package, ambient temperature and engine. Your groups I, II and III have better P-V coefficient than PAO's and that could play a role as well. EDGE EP was quiet in my truck, but so was the OE fill. Even quieter is the new Rotella Gas Truck. EDGE became a bit noisier as I put miles on it. Don't know why. Wasn't anything significant though.
 
Messages
4,165
Location
WA
Castrol has a unicorn blood in it. It envelopes the valve train in this essentially making metal to metal contact impossible....‚ Ok, seriously...dunno. I've used lubes that, at least to me, seemed to elicit more VT noise...but who knows if that's actually the case and not some psychosomatic effect.
 
Messages
5,069
Location
Midwest
Originally Posted by aquariuscsm
Does gold bottle Edge contain moly?
Yes, along with boron and titanium.
 
Last edited:
Messages
640
Location
Colorado
Castrol Edge, like Magnatec, probably has some kind of ester to attach to the surfaces. They have claimed a 1.7 dB reduction in sound power in some past marketing materials.
 
Messages
6,674
Location
California
Castrol Edge has Ti as part of the add pack, Magnatec uses a little ester to cling onto metal. P66 also uses Ti in Kendall and Philips 66 lines with Liquid Titanium. I haven't seem an VOA of Castrol's oil in a while. SOPUS and Chevron are fans of moly, and so is Idemitsu.
 
Top