Then I guess our fat old Northern Pacific Rattlers in Northern California would give something like 20W-50, or would they just be good for gear lube?

 

Thanks BlackC6, hopefully I'll be enjoying my vette in April. Please note that I do not recommend mixing different brands of oil, that was Stinky.

 

My bad, that may explain his username though.....

 

Damn good info, thank you.

is it then appropriate to extrapolate, from teh given data, that the 10W-60 recommended by BMW in my 02 M3 daily driver is not the best oil for winter?

 

Is using Mobil 1 0w-40 ok in a C6??

 

No. 5 w 30 Mobil 1 or equiv with same GM spec.

One thing you'll notice is the newer extended mileage M1 does not have the GM Spec or energy cons. label.

Stick with the original M1 5w30. or other brand i.e. RP w/ gm spec.

10w40, 20w50, 0w40 ... all no no's.

 

You mean you dont just drop the snake in the oil hole?? I thought that the diameter of the hole was equal to the size of the snake (oil) to use.

 

Haven't you seen the RonCo Snakeamatic in the performance parts book? It's a version of the old Bassamatic as seen on SNL. (You younger guys don't have a clue to what I'm talking about, huh?)

 

Unfortunately I do.

I was picturing something like an old Maytag gasoline engine powered wringer washer so you could process the snakes where you caught them.

 

The pressure in the center of the hydrodymanic wedge is over 10,000 PSI. (This does not detract one iota from what you said.)

Four issues:

A) cold start: When starting an engine, the oil is very thick, especialy when the oil temperature is below 0dF. At 0dF the 5W-30 oil can be as thick as 500 centiStokes whereas when the oil is at operating temperature it is only 10-12 centiStokes. At -20dF this same oil can be as thick as 1500 cSt. When the oil is really thick the hydrodynamic wedge can become 'stiffer' than the surface strength of the bearings (approximately the surface strength of lead), and instead of lubricating the surfaces, the oil becomes a virtual solid and scrapes them away at the surfaces. Be gentle with your engine until you get some temeprature in the oil; the thicker the oil you use, the more gently you need to be until you get some heat into the oil.

B) HPDE oil selection:: If you end up having issues with oil temperatures (say above 280dF) the correct long term solution is to add oil cooling capacity and not to increase the weight of the oil.

C) engine oil has a property whereby a thicker oil will thin out more under stress. This is known as viscosity tracking. An oil that is too thick will run at higher temperatures than an oil with the proper viscosity*, and an oil that is too thin will also run at higher temperatures. So, to a very first order, you can experiment with oils at the track and select the oil that results in the lowest running temperature. For one of my race cars (with lots of oil radiator area) this ended up being a 5W-40 oil, 5W-30 oil ran 3-5dF hotter and 15W-50 ran 15dF hotter under similar circumstances (same track same 103dF summer Texas weather). I ran this experiment with three 15W-50 oils, three 5W-40 oils and one 5W-30 oil (one of the thick 5W-30 oils), all top notch synthetics. The 5W-40 oils end up running at 260-265dF in the heat of Texas summers.
[*] note the careful selection of viscosity and weight. The viscosity of an oil changes with temeprature, the weight does not. Viscosity is a measure of the oils resistance to flow under pressure, it can be measured in absolute (Poise) or kinemetric (Stoke) units. The SAE weight of an oil is a min-to-max viscosity at a given temperature. A 30 weight oil is between 9.6 cSt to 12.4 cSt at 100dC (212dF). The winter specification is a different measure of the 'weight' of the oil at 40dC and for a 5W- oil the viscocity (for a 30 weight oil) is between 55 cSt and 72cSt.

D) The single best number for cars operating on road race tracks is the HTHS number. This number represents measured data with the oil under high levels of stress and at a temperature (300dF) close to what our cars run at at the tracks. There are 5W-30 oils with HTHS numbers less than 3.00 and there are 5W-30 oils with HTHS numbers above 3.6 (these oils invariably come from the thick end of the 5W-30 specifications--and M1 does not happen to be one of them--however, M1 10W-40 does work just fine).

 

Mitch, David,
Thanks for some very good info.

For those interested, the following AMSOIL products meet GM Standard 4718M,
AMSOIL Series 2000 0w30
AMSOIL SAE Synthetic 5w30

AMSOIL does make two 40 weight oils that may be better suited for the track and those willing to step outside the owner's manual requirements.

P.S. Contrary to one of the posts above, AMSOIL does not cost twice what Mobil 1 does. Actually the AMSOIL Preferred Customer Program price for the 25,000 mile AMSOIL SAE Synthetic 5w30 is less than the price I saw on the 15,000 mile Mobil 1 Extended Performance oil at Walmart this week. AMSOIL Corporate policy prohibits me from discussing prices online, but if anyone want them, drop me a PM, email or Request a Free AMSOIL Catalog.

 

Mitch, thank you for taking teh time to write that out. I saved it for future reference if you dont mind.

 

BlackC6 (which mine is also), I am using two different oils, Amsoil 5w-30 and Castrol Syntec 0w-30. The Syntec is a great oil but it does not have the 4718M spec, though I suspect it would pass if tested. The Amsoil is great but has been recently reformulated and is closer to Mobil1 now than it used to be, ie. a little toward the thin side of 30 weight.

Just a couple of more options for you.

 

Is there a tuner or performance shop out there that does not recommend moving from 5w/30 to 10w/30. Two performance shops with whom I talked recommended the 10w/30.

 

10W-30 will do no harm unless it's really, really cold. Like under 0F. Whether 10W-30 has any real advantage over 5W-30 with modern high quality synthetics above about 0F is questionable.

I still use 10W-30 because it will do no harm where I live and may have a small advantage when hot and worn.

 

Mobile-1, 5W-30. Have had no problems with the C4, C5 or C6.

 

Motor Oil = Religion

I recommend Buddhism

& Shoot everyone that doesn't believe the same as you, oh, wait that's muslim, sorry.

John

 

Lingenfelter recommends 15W-50 Mobile 1 for their 403cid engine. Only place I have been able to find it is Wally World - but at least it is available in 5 quart jugs and individual quarts. Of course, it is more expensive than the standard 5W-30.

 

I searched this subject well before changing the reccomended mobil 1...

I find that in my situation (dont have cold winters here) RedLine 10W-30 has the best HTHS rate and also as its such a small difference from the low value to the high one (meaning it has a lower Viscosity Index than others) it actually has more lubricative oil instead of all the additives.

At the Bob is the oil guy forums, they do used oil analysis every oil change and they found that redline 10w-30 protects your engine better than other oils but needs to be changed more often at like maximum 6k miles (i change mine every 3k so dont mind about that either)

What works 4 me might not 4 u so check out bob's forum

 

I prefer bottled water.