when should i consider a 10w30 over 5w30?

[Mr. Boston]

Thanks everyone for confirmation.

 

[ekpolk]

To expand upon what Goldenrod said, you really need to examine the product data sheets on the particular oils you're comparing before you can meaningfully answer your question. To make the point even clearer, I use German Castrol at present in both of our vehicles. GC is a 0w30 oil, but when hot, it's considerably "thicker" than most mainstream 5w30 or 10w30 oils. GC is about 12.5 cSt at 100 deg C, whereas for example the Mobil 1 5w and 10w30 oils all hover around 10 cSt. Then, in order to guage how well the oils hold their viscosity under stress, you need to examine that HT/HS (high temp/high shear vis) number.

Again, there are many factors to consider, but generally, I would not fret if I were in your shoes -- I'd probably use either with no worries, unless one of them displayed unwated symptoms (consumption, noise, etc.). Also, if my car developed consumption, I'd take a more significant step up than going just to a thicker 30.

 

[Winston]

ekpolk,

You are absolutely right about checking the data sheet to find the exact viscosity for a particulare oil. However, the newer SM Mobil 1 5W30 oil is now thicker than the SL version. 5W30 is now 11.3 cST at 100C, but the 10W30 is still 10 cST at 100C. The EP SM oils are now a bit thinner than the old EP SL oil. 10.5 and 10.25 cST.

Picking a favorite oil is a moving target.

 

[GMorg]

" when should i consider a 10w30 over 5w30?"

When 10w30 is cheaper and ambient temps aren't frigid.

 

[DaveInLA]

The owner's manual in my Altima 2.5 says that 5w30 is "recommended at all temperatures" but it's also "acceptable" to use 10w30 in milder climates (above freezing, basically).

Before I began changing my own oil, I took my car to the local dealership, and they use 10w30 yearround. Here in LA, I don't think I've ever seen it get colder than 40 degrees.