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Originally posted by DemonSVT:
Originally posted by EuroTour99:
Originally posted by DemonSVT:
6 quarts of Mobil 1 0W40
What are the advantages of running this weight oil as opposed to a 5w30? I noticed Mobil 1 lists it as a "European" car formula
Better thermal viscosity protection under operating temperatures. I drive quite HARD.
For "realistic" purposes a 0W40 is a 9.5 weight oil at 80 degrees. The only time it's quite "thin" acting is in cold weather and that's a good thing.
For ref - At 80 degrees during start up.
0W30 = 7 weight
5W20 = 9 weight
5W30 = 12 weight
10W30 = 17 weight 
10W40 = 20 weight 
20W50 = 32 weight  
Just remember, as long as the oil can be provided to every component under all conditions, that's with tight tolerances and all, then it is sufficient.
I still can't imagine using a 0 weight oil unless I lived in Montana or something.
Also, those relative weights are not really accurate. The weight of the base oil is the first number. The second number indicates the thinning resistance. Thinning being a bad property for oils and the reason they add additives. The polymers help reduce thinning. THe thinning resistance of a heavier oil is the best, but its low temp properties will kill a motor, hence the multi-weight.
20w-50 oil is a 20weight oil that won't thin more than a 50wt at high temperature. It doesn't gain oil weight.
Here is a good URL explaining it and some brief quotes:
Multi Grade Oil explanations
Quote:
Multi viscosity oils work like this: Polymers are added to a light base (5W, 10W, 20W), which prevent the oil from thinning as much as it warms up. At cold temperatures the polymers are coiled up and allow the oil to flow as their low numbers indicate. As the oil warms up the polymers begin to unwind into long chains that prevent the oil from thinning as much as it normally would. The result is that at 100 degrees C the oil has thinned only as much as the higher viscosity number indicates. Another way of looking at multi-vis oils is to think of a 20W-50 as a 20 weight oil that will not thin more than a 50 weight would when hot.
Here's another interesting point: (makes me want to revise my usage of 10w-40.
Quote:
Always use a multi grade with the narrowest span of viscosity that is appropriate for the temperatures you are going to encounter. In the winter base your decision on the lowest temperature you will encounter, in the summer, the highest temperature you expect. The polymers can shear and burn forming deposits that can cause ring sticking and other problems. 10W-40 and 5W-30 require a lot of polymers (synthetics excluded) to achieve that range. This has caused problems in diesel engines, but fewer polymers are better for all engines. The wide viscosity range oils, in general, are more prone to viscosity and thermal breakdown due to the high polymer content. It is the oil that lubricates, not the additives. Oils that can do their job with the fewest additives are the best.
*****
The explanation above in that website is by Ed Hacket and it has been used dozens of times over on different websites that I have found.
*****
Last edited by warmonger; 05/29/05 04:13 PM.
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
See My Mods
'05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red
'06 Mazda5 Touring, 5spd,MTX, Black
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It seems many people are suffering from not really understanding the terminology or the properties of the oils that we are interested in. This is a good site to educate ones self: Very good site describing properties of oils. I spent some time dredging this stuff up for people because I for one am tired of getting ripped on for choosing a thicker oil I believe that I am choosing correctly because I took the time to evaluate the operating temperatures I actually run my car in. A 20w-50 oil is NOT a 50 weight oil. It is a 20w oil that in 100F ambient temps will provide a better oil barrier on the bearings than a 5w oil. For the last time... it doesn't thicken up or become more like a thicker oil when it gets warm! None of the oils do that. The additives will keep certain properties behaving like a that of thicker oil, but not the thickness of it. It pours good down into the sub freezing temps, below 30F, but it would not be my oil of choice if my winter temps were below 35-40F consistently. It is not what I run in winter anyway. With winter time I've run a 5-30, 10-30 or a 10-40 depending. In AZ and TX the winter temps rarely got below 45-50F. Hell in AZ my lowest winter temp was about 55F during the day and 30 in the middle of the night. I like the advice to use the narrowest multi-grade oil corresponding to the temperatures the car will see. I say this knowing that I change my oil frequently and that because of the frequent changing the thermal breakdown problems of dino oil are less of an issue. I choose right now to change oil more frequently rather than use a higher priced synthetic and run it longer becuase I feel that there are too many contaminants introduced into the oil over a long term that will not be filtered out, despite whether the oil remains good or not. With a turbo I will have more risk so I change the oil every 3-5K miles. Why would anyone trade away the bearing protection that a thicker oil can provide, IF the thicker oil can pump well enough on startup, not be so thick that it creates serious drag, and still flow well with plenty of sheer strength at high temps? Aren't we using our engines once they warm up to high temps? Hell, as long as the oil can pump through to the top end quick enough on startup, then I have no problems letting the car warm up before getting on it in order to have a thicker oil to prevent thinning problems at operating temps.
Former owner of '99 CSVT - Silver #222/2760
356/334 wHP/TQ at 10psi on pump gas!
See My Mods
'05 Volvo S40 Turbo 5 AWD with 6spd, Passion Red
'06 Mazda5 Touring, 5spd,MTX, Black
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5w-20 Redline in an 04 Mazda 6s MTX with the revised sump.
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Originally posted by warmonger:
Also, those relative weights are not really accurate. The weight of the base oil is the first number. The second number indicates the thinning resistance. Thinning being a bad property for oils and the reason they add additives. The polymers help reduce thinning. THe thinning resistance of a heavier oil is the best, but its low temp properties will kill a motor, hence the multi-weight.
This is only correct for dino juice. The base weight of synthetics are from the 2nd number, and do not have VI improvers.
More info:
http://members.rennlist.com/oil/Motor%20Oil%20101.htm
I'm using 5w-30 dino juice for the first 3000 miles on my Noble M400 (3.0L duratec, twin turbo). From my oil pressure gauge, it seems I can afford to drop pressure down just slightly. I'm going to 0w-20 Mobil 1 after the 3000 miles are up.
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0W20 is quite thin for a turbo charged engine. Even with the extra protection of being synthetic.
2000 SVT #674
13.47 @ 102 - All Motor!
It was not broke; Yet I fixed it anyway.
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I think and key word THINK. I am no expert in anything realy  But i think alot of people try to run the lightest oil because they are taught that thinner oil is easer to pump therfore is less drag on the motor and therefore more hp. Obviously thats a hole artical just summed up in a few short words. But you get the idea. Maybe its beieved that thinner oil will protect better because it can find its way into tighter tolerances,  Def. a good thread so lets keep it alive 
98 csvt t-red.. sho-shop intake, b&m, fidanza, spec1 clutch, Torsen, DMD,optimized Y& TB, Brullen, rear strut bar,h&r's,17" konig traffik's.
"I say what I mean and I do what i say"
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Originally posted by DemonSVT:
0W20 is quite thin for a turbo charged engine. Even with the extra protection of being synthetic.
Mobil 1 5w20 is what's specified in the owner's manual. The 0w20 is virtually identical at operating temperatures, and simply flows SLIGHTLY better at startup (if at all). Both are on the thicker end of 20 weight, actually performing close to a 30. I'm planning to use blackstone's for oil analysis. If it seems like the oil is sheering down too much, I'll probably switch to Redline 5w20, which has a HTHS of 3.3, on par with many 30 to 40 weight oils.
Around town, with the 5w30 oil, I'm at 65-80 degrees C. The maximum I've ever measured was 85 degrees C, and that was when I was stuck in 8 miles stop & go traffic, uphill, in the California/Nevada desert. Oil pressures seem normal, just above the ideal 10 PSI per 1000 RPM.
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Hey fella's, This might be some interest to you. http://www.mazda6tech.com/articles/maintenance/used-oil-analysis.htmlThis is a collaboration of all the current Mazda 6 UOA's. The 6s uses the 3.0 V6 Duratec platform, so the wear metals should be similar to what you'd see in the contour's. Ignore the 6i readings, as thats the 2.3 engines.
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