quote:
Originally posted by Dr. T:
Well, if the same engine is using 5-30 one year (eg. Honda) and then 0-20 is OK the next w/o any engine changes, then why not use 0-20 in an LS-1 to reduce wear? (3MP???????)
In other words, if an engine is using 5-30 in N.A. and 15-40 or 20-50 in Australia then it should be OK to go the other way...ie. to a 0-20 to reduce wear. Right? The engines are no different between the 2 countries....
Again, I challenge anyone to take conventional 5-20 and a 15-40, do 10k intervals (Euro standard even before synthetics) each and do a UOA (assuming this has some indication of what's going on). None of this 3k OCI stuff...
Hey Doc T:
If you're confused by this issue, and I'm confused by this issue, and the other oil anal-compulsives out there are confused by this issue, then how about the average motoring public??
BTW I did ask GM techline and they said in NO uncertain terms to NOT use ANY xW-20 oil in ANY LS1 or truck Vortec, a derivative of the LS1.
I too am all for a carefully controlled engine dynometer test that fully meets Chi Square and ANOVA statistical requirements.
Take identical motors, say an LS1, run one motor on Mobil 1 0W-20 and the other motor on Mobil 1 15W-50. Do equivilant 10,000 mile OCI (250 hour?), at 100% load and WOT, and stipulate like most German engine makers that NO makeup oil is allowed.
I would LOVE to see a UOA comparison from that test. I would also want to see both motors torn down and mic'd to compare actual wear on the camshafts, cylinder bore/taper, rings, etc.
Oh, Doc T, here is an interesting tidbit for you: the LS1 and the Truck Vortec both recommend a 5W-30 year round in their normal production vehicles. The same exact motor, as a "crate" motor (It goes down the same engine assembly line as the motors destined for cars and trucks)recommends a 10W-40 year round.
THis is from GMPP (General Motors Performance Parts). What do you think? Interesting, no??
Because motors are made so much better now, and even cheap Brand X oils are WAY better than oils of 5-10 years ago, I think 150,000 miles out of a motor running the cheapest oil is probably reasonable. For the average driver, that may be good enough.
Those of us who want/expect things to last forever may not be satisfied with that. I know I'm not, so I carefully adjust my viscosity to my ambient temperature.
Unlike the rest of the world, we have CAFE to deal with. This benefits the manufacturer, not us. Remember this is a FLEET AVERAGE that applies "credits" to the manufacturer to offset poorer results from gargantuan SUV's and pickup trucks.
What is the difference, maybe 0.2 MPG on a car that already gets 40 MPG? Maybe 0.02 MPG on a V10 SUV?? We wouldn't even notice that, like somebody posted maybe $10 over tens of thousands of miles.
Apply that miniscule amount over hundreds of thousands of units and the manufacturer is really ahead: the "credits" can be applied to offset the poorer results elsewhere.
Some European makers are "turning around" to lighter oils. For example, in Europe VW 506.x specifies a synthetic 0W-30 which was co-developed by Castrol: Castrol SLX LongLife II. This oil is only for certain VW/Audi engines and they warn to NOT use it in their other motors.
The oil must have a pretty beefy additive package to allow up to 24 month / 50,000km OCI. Although they don't publish MRV and Brookfield data, the pour point is -39 C. Other 0W-30's have pour points of -49 or lower.
Jerry