We were having a conversation the other day regarding 10W vs 5W. One person had mentioned that he was gonig to switch from 5W to 10W. he stated that "it's too hot in houston for 5W, the oil is too thin". I thought to myself that that didn't matter that much. I mean after all, the temp is still with in the 5W range. Plus 5W protects better in cold start up...

thoughts, ideas?

 

In the summer, the front main seal on my VG drips when I run 5W, but does not when I run 10W. Very small amount, 4-5 drops when I shut the engine off after running a while.
it will do this in summer or winter..

Usually I'll run 10W in the summer and 5w in the winter anyway, just because of the cold start stuff.. I'll be glad to clean up a few 1" drips on my driveway if it'll help the engine last longer.

I recently changed my PCV valve, and don't recal seeing any new spots on the driveway either.. I'll check tomorrow and see if it stopped. I've heard that if your PCV valve is bad, it can cause enough pressure inside the engine to cause oil to seep from the seals..

Keep in mind this is with an engine with over 112k miles on it. I dunno exactly when it started dripping, but I'm guessing it was around the 90k mark..

 

between the two grades. 10W30 is really just thicker when cold, hence it's only appropriate in hotter temps. 5W30 is thinner in colder temps.

From my perspective, though, since not only outside temp but also ENGINE TEMP affects the oil temperature, I want the thinnest stuff possible so that the oil pressure gets to normal ASAP after a cold start. I'd try 0W30, but since it's kind of a newer grade that's not been tested much and Nissan doesn't list it, I'm wary to try it. Still, though, theoretically, it should give the same, if not similar, high temp viscosity as 10W30 but be nice and non-thick during startup to reduce startup wear.

 

5W-30 seems fine for me in Shing Land

btw, just testing the sig =P

 

I was told to use what the car manual called for. either 5W or 10W or striahgt 30W or whatever the manual says depending on your cars make. I personally don't know what my manual says about the subject. so no help there. However after working in the auto industry at various jobs, most mechanics agree, that newer engines run better with 5W untill about the 50 - 60 kmi. mark. and then would be better to switch to a heavier weight for more wear protection. I also know for a fact that 5W seems to last me a litte longer than 10W. Ex I can run about 4K on 5W and still maintain a nice dark gold color. the 10W seems to get it darkness at about 2800 to 3200. This is south TEXAS climate if it matters. you know there should be a climate application on oil brands websites I believe just my 3cents ay.

 

that trying to judge the how good the oil is by color is not a very good system at all.

Ususally when I change my oil at 5k or more, the oil is black. My last change was at 7k.... oil was black. sent to get tested... it's all good. So I think judging based on color is very deciving.

-Shing