Topic: 5 or 10W

[siwash]

which one is best for winter?  thanks!!

 

[articsteve]

5W20 is best for winter.

[Titanium48]

5wXX is thinner than 10wXX at low temperatures, making for easier starting and quicker distribution of oil in the engine.  Check your owner's manual before using 5w20 though,  most cars need 5w30 oil.  The viscosity difference between 5w20 and 5w30 is quite small at subzero temperatures but 5w20 is too thin for many engines at operating temperature.  You can also get 0w30 synthetic oil if you're willing to pay for it.  The 0w30 will still flow at -60°C!

[johngenx]

What kind of car?  Most small-tolerance late-model Japanese-maker cars use 5-20 or 5-30.  Use that in an older inline six Mercedes or BMW and you'll have a dead engine in weeks.

[JD]

Running Full Synthetic 0-30 in my cars, it's fantastic... Offers superiour cold start protection and fantastic operating tempurature viscosity!

[articsteve]

The Japanese (Honda and Toyota) have gone to 5W20.  Comprimises are made to the integrity of dino oil if the spread gets to far in the viscosity range.  For example 10W30 is preferred over 10W40.  10W30 is preferred over 5W30.  The Japanese settled on 5W20 and not 5W30 for that reason.

Synthetic oils eliminate that problem as we all know.  I use 5W50 in a worn Saab, BMW and now a 2.5 L Porsche.

[AVToller]

The Japanese (Honda and Toyota) have gone to 5W20. 

Gee, you better notify Toyota about the error they made in my Yaris manual bewcause it specifies 5W30 FOR ALL TEMPERATURES.

[yugrus]

5wXX is thinner than 10wXX at low temperatures, making for easier starting and quicker distribution of oil in the engine.  Check your owner's manual before using 5w20 though,  most cars need 5w30 oil.  The viscosity difference between 5w20 and 5w30 is quite small at subzero temperatures but 5w20 is too thin for many engines at operating temperature.  You can also get 0w30 synthetic oil if you're willing to pay for it.  The 0w30 will still flow at -60°C!

You have to be careful here though. 0w, 5w, 10w as well as 20, 30, 40 are ranges. While individual oil viscosities fit into the range, it does not mean that one oil is always thinner then the other. Viscosity charts are not linear, and their rates of change are pretty different.
Examples: At -20C Castrol Syntec 0w30 (made in Germany) is thicker then Mobil 1 5w30. In fact, it is thicker then M1 5w30 (or probably any other 5w30 oil) all the way from 150C down to -30C. At working temperature it is almost 40 oil.
On the other hand, Mobil 1 0w30 is thinner then M1 5w30 from cold up to about 30C, at which point they have very close viscosities while temperature rises.
RedLine 5w20 is even thicker at -30C. It gets the same viscosity as M1 5w30 only between 30C and 40C, at which point it becomes thinner as the temperature rises...

Also, ability to flow has very little to do with real life pumpability.
Oil is vast and very interesting subject.

[siwash]

it's an 04 corolla CE

[yugrus]

The Japanese (Honda and Toyota) have gone to 5W20.

I thought Toyota haven't yet. Do you know otherwise?
Siwash, I'm sure your owner's manual specifies 5w30 year round and 10w30 for warmer climate. 5w30 will work the best for you during winter. What brand of oil you're thinking about?

[Titanium48]

Points taken, yugrus.  I was only thinking of petroleum oils, the low temperature behavior of synthetics can be very different than petroleum oils and from other synthetics.  However, I thought that the "low temperature" viscosity for grading purposes was measured at 40°C, so how can a 0w30 be thicker than a 5w30 at that temperature?
Also, I've heard from Saturn people that the made-in-Germany Castrol 0w30 is good for cleaning the stuck oil rings that lead to oil consumption problems in Saturn engines.  Any idea where to get it in Canada?

[yugrus]

Product data sheets specify viscosity (ASTM D 445) @ 40C and 100C. API viscosity grade at working temperature (100C) is determined by the Low-Shear-Rate Kinematic Viscosity. The range for 30 grade is from 9.3cSt to 12.5cSt. Mobil 1 5w30 is at 11.3cSt and Castrol Syntec 0w30 is 12.2cSt, almost at the brink of 40- grade.
Low-temp grade is determined by Low Temperature Cranking Viscosity, which is a different animal. It is a bit trickier because 0w oil has to have less then 6200cP @ -35C while 5w less then 6600cP @ -30C. Different units measured at different temperatures.
You use oil viscosity calculators and viscosity graphs to get the viscosity data at the given temperature. And German Castrol (GC) is definitely thicker then M1 5w30 under any temperature you'd experience in Ontario.
Someone at another forum compiled the following viscosity table. Look closely, that's a lot of fun!
Sorry, I couldn't figure out how to post the table with proper spacing... Will be smarter next time.

TEMP     M1 0W-40     GC 0W-30     M1 0W-30     M1 5W-30     M1 10W-30     M1 0W-20     RL 5W-20
                     
-20   2661.5   2609   1994.8   2225.1   3424.8   1712.7   2995.8
                     
-10   1197.8   1127.1   872.4   944.7   1332.9   730.8   1165.3
                     
0   599.3   546.6   428.3   452.9   595.7   352.8   521.4
                     
10   327.6   291.8   231.3   240.1   298.3   188.5   261.8
                     
20   192.9   168.8   135.3   138.3   164.1   109.5   144.5
                     
30   121   104.4   84.6   85.5   97.6   68.3   86.3
                     
40   80   68.4   56   56   62   45.1   55
                     
50   55.4   47   38.8   38.5   41.6   31.3   37
                     
60   39.8   33.7   28.1   27.7   29.2   22.6   26.1
                     
70   29.7   25   21   20.6   21.4   17   19.2
                     
80   22.7   19.1   16.2   15.8   16.1   13.1   14.5
                     
90   17.8   15   12.8   12.4   12.5   10.4   11.3
                     
100   14.3   12   10.3   10   10   8.4   9.1
                     
110   11.7   9.8   8.5   8.2   8.1   6.9   7.4
                     
120   9.8   8.2   7.1   6.9   6.7   5.8   6.1
                     
130   8.2   6.9   6   5.8   5.7   5   5.2
                     
140   7   5.9   5.2   5   4.9   4.3   4.4

[21Rouge]

What kind of car?  Most small-tolerance late-model Japanese-maker cars use 5-20 or 5-30. 

I do wonder about this. Hondas use the 5-20 but why has Toyota not made the jump to such a viscosity? Both Japanese manufacturers produce 'small-tolerance' engines.

[yugrus]

Also, I've heard from Saturn people that the made-in-Germany Castrol 0w30 is good for cleaning the stuck oil rings that lead to oil consumption problems in Saturn engines.  Any idea where to get it in Canada?

I heard rumors that it does, and in fact it can, because it is PAO-ester based. Esters are very good cleaners, and this oil contains some very advanced ester formulations. BTW, RedLine oils are ester-based which most of the time means very clean engines.
It still could be found at Canadian Tire, PartSource and Walmart. Look for "Made in Germany" 1L bottles, and check first two digits of the numeric code, if I remember correctly. You want 02, 03, 04 years of production. Apparently Castrol has changed formulation in 2005, the oil is not green anymore, just plain amber. It is still in the air if this oil is as good as the green version.
Oh yeah, green GC produces outstanding results in used oil analyses. I personally run two analyses on this oil, amazing wear numbers.

[articsteve]

Any true 100% PAO motor oil will clean out a motor more than a regular dino oil.  That is why people complain of leaks in older motors.  If you use this type of 100% PAO oil change your filter again after a thousand miles incase the PAO oil has dislodged lots of junk.

Here is an interesting read on the USA Castrol "synthetic".

All synthetic oils used in performance applications are based on two
>kinds of base-stock compounds. PAOs and Organic Esters. The organic
>esters are superior to a certain degree (they're used in jet engines
>for their heat resistance) but the PAOs are more cost effective and
>offer superior detergent properties (keeping the engine clean) and
>tend to be the bulk of any sythetic oil including Mobil 1. Usually
>around 80% is a PAO and the rest are organic esters. In the synthetic
>oils that were pioneered in applications such as aviation and
>hi-perfomance this is what was used.
>
>That said there's a newer process of refining regular dino-oil that
>yields far better results than conventional refining. It's called
>hydrocracking or isodewaxing. This process yeilds better quality motor
>oil from petroleum stock because of far more agressive molecular
>manipulation which creates base oils that have some of the beneficial
>attributes of PAO and organic esters. While hydrocracked oils offer
>significant benefits over regular oil they do *not* outperform PAOs
>and Esters.
>
>Castrol Syntec was once a PAO/Ester based oil similar to Mobil 1.
>Around Decemeber of 1997 it was quietly changed to a
>hydrocracked/ester blend. This means that the bulk of the oil is in
>fact regular dino oil that has been subject to the hydrocracking
>process with a small amount of organic ester thrown in for good
>measure.
>
>Mobil took Castrol to task over this and filed a complaint with the
>BBB and FTC. During the long legal battle that followed Mobil claimed
>that Syntec was reformulated in 1997 without notice and that it could
>no longer call itself a synthetic. Castrol's response was that the
>isodewaxing process offered a significant benefit and altered the
>molecular structure of the base stock significantly enough to qualify
>calling it a "synthetic". They also asserted that since Mobil did
>derive their PAO/Ester basestocks from petroleum (duh) that any
>significant molecular manipulation of crude oil could be labeled as a
>synthetic product. Furthermore there is no real definition to explain
>what exactly a synthetic is since the SAE decided to drop the ball and
>avoid the issue altogether rather than issue a precise standard.
>Castrol used this defense to say that synthetic oils do not
>necessarily have to be composed of PAO/Ester compounds. That
>hydrocracking yields a sufficiently different product from regular oil
>to qualify as a synthetic.

[articsteve]

I do wonder about this. Hondas use the 5-20 but why has Toyota not made the jump to such a viscosity? Both Japanese manufacturers produce 'small-tolerance' engines.

Ok I just asked my son who works for a dealer conglomerate that ownes and operates Toyota, Honda and Kia shops in southern Ontario he says their Toyota dealerships were sent 5W20 bulk last year but nobody thought about what that might do to domestics cars that are lured into the dealership on give away oil changes as a marketing strategy to get people into the show room.  So I was in error as Toyota uses 5W30 in winter and that won't change.  He says for the same reason the bulk turns to 10W30 for the summer (domestic traffic).  The shops only carry the one bulk oil at a time.

[barrie1]

The swap between the 10-w-30 and the 5-w-30  oils has been used for many years with Millions of Car owners . Most folks with their everyday vehicles change for the seasons no matter what Brand of Product they use. The tolerances of the newer engines are much tighter now and you don't need the heavier oils of the past as much as they were needed before unless you are running something very specialy built under the hood. The higher the compression in my mind dictates a better grade of oil and a proper maintenanace program for the results you need. Race Engines generally run a much higher weight of oil in comparison to the everyday street engines which most of us drive. Changing the oil is the main secret in getting a long life out out of any engine as most of them are capable of going almost indefinitely if maintained correctly. Altho rare but some gas engines have been known to go as long as a Million miles before they were pulled. Very common in the big rigs as well. 

[yugrus]

There's absolutely nothing wrong with Group-III Castrol oils that they claim to be synthetic, they do show very good results. The only problem is that almost all Syntec oils are overpriced for what you get for your money. Many different oil brands and types deliver similar results, at less then 1/2 of the price.
But German Castrol 0w30 really stands out of the crowd. Get it if you can score it and keep for the summer heat. This oil is thick and incredibly stable, don't be fooled by 0w designation.
I was right, every bottle has imprinted code starting with "M", so you want M02..., M03..., M04. The oil has greenish color and very different smell. M05 MIGHT be the same good deal, slightly tweaked. Or may be not...
Don't buy "Made in USA" bottles, this is not what you want to pay for.

[articsteve]

There's absolutely nothing wrong with Group-III Castrol oils that they claim to be synthetic, they do show very good results.

Don't think I'll ever agree with you on that one. But I have also heard good things about the European Castrol which is part of BP I believe.  Lately I have switched 3 vehicles to Quaker State 5W30 and 5W50.  I got boxes of 6 litres for $24. at Crappy Tire.  Mobil 1 just getting to expensive.

Below is a cut and past from a Shell pdf:

SAE Grade 5W-30 10W-30 5W-50
Gravity, °API 34.2 33.7 33.7
Flash, °C(°F) 227(440) 227(440) 224(435)
Fire, °C(°F) 250(482) 250(482) 250(482)
Pour, °C(°F) -45(-49) -40(-40) -37(-35)
Viscosity - - -
@ 40°C, cSt 56.8 61.9 1104.8
@ 100°C, cSt 10.50 10.50 18.2
@ 100°F, SUS 288 315 531
@ 210°F, SUS 61.9 61.9 92.8
Viscosity Index 177 160 193
CCS Viscosity @ Temp. °C(°F), cps Max. 6600 @-30(-22) 7000 @ -25(-13) 6600 @ -30(-22)
Low Temperature Pumping Viscosity - - -
@ -35°C(-31°F), cP (max.) 60,000 - 60,000
@ -30°C(-22°F), cP (max.) - 60,000 -
MSDS @ -30°C(-22°F), cP (max.) 14953- 1507260,000 14953-
Material Number - - -
6 x 946 ml 55 Gallon Drum 2910711652 1121029105 1202029103
208 L 6/1 Quart Case 1165212071 1121011255 1202014124
09/18/2003 12:47 PM

[yugrus]

There's absolutely nothing wrong with Group-III Castrol oils that they claim to be synthetic, they do show very good results.

Don't think I'll ever agree with you on that one.

UOA (used oil analyses) are really good tools to track the performance of particular oil in particular engine. Wear numbers for Syntec 5w30 are not worse then those for Havoline, Pennzoil, etc. Although there is no point to pay more for it.
BTW, it is quite common that Group-II/III oils show the same or better wear numbers then synthetics...