what is the best engine oil for a turbo ?

Thanks

I don't know mate I don't use the stuff :D.

 

Only kidding ;)

 

Semi synthetic 10/40 - 10/60, change every 3,000 miles.

Hi Stuart

 

Do you think 0/40 Castrol RS is ok for the Winter?.

 

 

Cheers

 

 

PS Appologies for the Hijack....

been ok summer and winter in mine for more than 3 years - and it fits with Nissan's own recommendations

been ok summer and winter in mine for more than 3 years - and it fits with Nissan's own recommendations

 

 

Top man. Thanks.

The manual says this :-

 

It seems it is not recomeded then. I think I will use it this time but go for a 10/60 next time. Or could I mix half and half over two different oil changes?.

 

 

PS. Adminerator, lol. :D

stuart it was only read about you having to put a lot in that i thought better check mine. i always thought it would have been fully synthetic ?

generally a 0W rating is not preferred for our cars - its a bit too thin.

I used RS 0/40 when I first got my car and the next thing I knew my values were all fooked. I'm not saying this was the cause I'm just saying I only use Castrol Magnatec now. 10/40 and change every 3,000 miles.

Watch that you are interpreting the rating properly - the first number is the viscosity when stone cold - its still thick because its cold. The second number is the viscosity when its hot = 40 for RS 0-40! A 0W is better for a cold engine than a 5W and the 40W applies when its hot. Nissan says a 5W 20 is not recommended for a turbo - correct because of the 20 weight when hot - just a bit thin for hot!

 

Remember also that such range oils 0W-40 or 10W 50 were not commercially available when this was written.

 

also nowhere do you see 60 referred to that some of us seem to use to quieten a rattly engine - thats really on the thick side and for Texas summer temperatures!

 

A high cold viscosity will help you blow out seals and gaskets due to the high start up oil pressure. Remember oil pressure is a guide to whether or not the engine is lubing it doesnt tell you what the amount of flow is and that is important. Thick oil will give high oil pressure and slow flow - not necessarily good!

 

Maybe my interpretation is not 100% correct but its clearly a few percent better than some here - what confuses me now with this chart is the 20W 20 being OK from -10 to more than +40Deg C. Where's our oil expert that works for Shell?

Oil Viscosity

 

Weighing in on engine lubrication

 

 

By: Wayne Scraba/autoMedia.com

 

 

Most people are familiar with oil's Viscosity Rating—10W40, for example. However, very few know that the "W" refers to "winter," not "weight." And most of us have no idea what the weight-rating numbers mean other than that the vehicle's manufacturer specifies a particular viscosity. This story deals strictly with viscosity; we're saving the petroleum vs. synthetic debate for later.

 

Oil Duties

Inside an engine, oil is in a Catch-22 scenario: It has to seal rings and valves, but it also must reduce friction. In simple terms, oil has to accomplish two functions that have directly opposite requirements.

 

The viscosity of any oil changes with temperature. The higher the temperature, the lower the viscosity—the oil thins out. On the flipside, the lower the temperature the higher the viscosity. Because of this, the Society of Automotive Engineers (SAE) has established a series of viscosity classifications that establish oil performance at 100 and 0 degrees Celsius (212 and 32 degrees Fahrenheit, respectively).

 

Highs and Lows

Low-viscosity oils flow better than high-viscosity ones—the lighter-weight fluid is easier to pump and therefore circulates faster through the engine's various galleries. Low-viscosity oils also maintain a lower oil pressure, but the oil pump delivers a greater volume through the galleries than it would with thicker (higher-viscosity) oils. Heavier oils also tend to operate at higher temperatures because the oil pump has to work harder to force the lubricant through the system. Oil does not compress readily, so the added pressure increases the temperature. In the end, high-viscosity oils maintain a higher oil pressure, but the pump delivers a smaller volume of oil.

 

Multigrades

Multigrade oils typically begin as base oils, such as 10W. Then viscosity-index modifiers (polymers) are added in an effort to stabilize the viscosity. This allows a 10W40 oil to flow like a 10W at cold temperatures and a 40W at higher temperatures.

 

The multigrade oils' viscosity modifiers are long-chain molecules that lessen the change of viscosity with temperature variance. In the past, the polymer additives (used to thicken the oil) were sometimes susceptible to viscosity loss. Permanent viscosity loss occurred when high shear forces (such as the relationship between the main bearings and the crankshaft) actually break the polymer molecules into less-effective smaller pieces. On a similar note, temporary viscosity loss also occurred when the polymer molecules aligned themselves in order to create a path of least resistance.

 

Fortunately, today's additive packages have improved oil's shear-resistance. However, oils with the same rating from different manufacturers can exhibit different viscosity ratings in an operating engine, depending on the shear stability of their viscosity-modifying additives.

 

For technoids, weights are defined thusly (stokes and centistrokes are measurements of viscosity):

 

"SAE 30 is SAE 30 no matter what the "W" prefix number is: 0W, 5W or 10W. This viscosity in centistokes (cSt) @ 100 degrees C is with the minimum of 9.3 cSt and a maximum of 12.5 cSt.

People seem to find with the 0 weight that it tends to start leaking out of seals as it very thin - engines sound a bit more rattley too. Especially true where the car is a few years old and hasnt been run on such a thin synthetic viscosity before as they tend to also clean out the crud as well.

 

Check out tt.net for a bit more info.

 

General rule seems to be if you havent run on synthetic before dont got for a thin one as you may spring leaks.

People seem to find with the 0 weight that it tends to start leaking out of seals as it very thin - engines sound a bit more rattley too. Especially true where the car is a few years old and hasnt been run on such a thin synthetic viscosity before as they tend to also clean out the crud as well.

 

Check out tt.net for a bit more info.

 

General rule seems to be if you havent run on synthetic before dont got for a thin one as you may spring leaks.

 

 

Seeing as I have no history on oil changes. I think I will go for a thicker oil... 10 or 15/40 should be ok right?!.

 

Cheers.

10W40 - cant go wrong ;)

10W40 - cant go wrong ;)

 

 

Cheers Paul. I need to have a word re: Tints in the next week or so.

 

 

PS. For sale 0/40 Castrol RS :rofl:

Cheers Paul. I need to have a word re: Tints in the next week or so.

 

 

PS. For sale 0/40 Castrol RS :rofl:

 

okey dokey :cool:

138k miles Castrol RS 0-40 purrs like a kitten, doesnt leak or burn it and original turbos quite happy still. Its the thick stuff that blows out crank seals and gaskets.

 

Think about the body - high blood pressure and too thick blood is a bad thing init;)

 

Thick oil might diguise a rattly engine but it also saps power.

 

So some still dont understand what 0W or 10W means?