Today's viscosity experiment

[uart]

Originally Posted By: widman
The problem with that chart is that people assume that it gives the same results. Here we are in the tropics. we get a dozen nights a year where the night-time temp drops below 65F, but not normally below 72 in the morning. So the noises and other problems develop.

So you rarely see a "cold" start under 72F. I don't see why that's a "problem" for the oil, I would have thought quite the opposite. That's basically the situation here in summer, at those type of "cold" start temperatures I would have thought the "W number" is just about moot. I mean 0Wxx, 5Wxx, 10Wxx 15Wxx, who cares when you're never starting below 72F.

 

[widman]

Since the noises were continuous, even after full temps were reached, I doubt that it would have mattered if it was a 5w30 or 10w30. But 40 was too thick.

 

[friendly_jacek]

Now, if the noise is piston slap, I posted a study several months ago showing piston slap was the quietest on 10W30, louder on 20W50, but loudest on 5W20. But, piston slap should go away with full temp.

 

[KCJeep]

Originally Posted By: Clevy
Originally Posted By: uart
Originally Posted By: Clevy
Originally Posted By: KCJeep
I'd rather run 5w30 in our new KIA as well, but of course here in NA I'm under warranty threats if I do. So the thickest 5w20's I can find will have to do.

What do they recommend in Europe? If the Europeans can run a 30 grade it's absurd that you can't however if they are consistent overseas as here then it could be that a 20 grade is ideal and not just adequate


Don't know about all of Europe, but "lube guides" from Castrol and Shell and Valvoline in the UK recommend 5W30 or 5W40 for most current model Kia's. Similar story in here in Australia with mostly 5W30 recommended, sometimes with a secondary option of either 10W30 or 10W40.


That's utter bull. If they can use those oils there then the consumer here shouldn't be threatened with denial of warrantee for wanting to use one of those grades. If its acceptable somewhere else then it should be acceptable here as well.
Even if a consumer decided to stick with a 20 grade,they should at least have the option.


My thoughts exactly, and why it irritates me so much. My manual says I can use grades other than 5w20 only if 5w20 is not available, which of course in the US isn't going to happen. And of course they printed 5w20 on the fill cap to further bully me. Yes it's CAFE and one of my main objections to it.

The manual does show 5w30 and 10w30 under the above exception, (no 5w20 available) but I'm of no mind to end up in a battle with a dealer over the warranty I may or may not win.

Not that I'm really all that opposed to the 5w20, I just don't like being bullied into it.

 

[mechtech2]

Originally Posted By: widman
Noise means something is hitting or rubbing. Without offering any technical proof, I's say that less noise is less hitting or rubbing, therefore more protection.


Could be true for all sorts of instances... but what about ALL of the operating conditions? Driving under load?