at operating temperature what is a thicker oil 30w or 15w-40?

 

The 15W-40. Think of it this way, a 15W-40 as a 15 weight oil that will not thin more than a 40 weight would when hot. Quiz tomorrow... : ;D<br><br>-Tom-

 

uhhhhhhhhh

 

Makes note to skip class tomorrow. ;D ;D

 

[quote author=Jack Thorpe link=board=8;threadid=5925;start=0#53520 date=1034775649]
uhhhhhhhhh
[/quote]

It pours like a 15 weight when cold, but is like a 40 weight when hot. Polymers, baby! Polymers! 8) (note to self: Dave, homeroom detention)

 

(note to self)<br>Call in with vision problems tomorrow. Just can't see going to class.

 

Raises hand slowly, Hey Teach, uhhhh, the dog ate my homework, uhhh, Top made me, forced me, honest, to go with him to some nasty beer halls. <br><br>Trying to hide behind Jack since dd4x4 has a better excuse than either of us ~Dave

 

so the &quot;W&quot; stands for Winter not weight right? At least that's what it says on the valvoline page! ;D

Tony

 

I understand about polymers but is the actual thickness more on the 15w 40 or is it thinner and just protect the same or as it heats up do the polymers allow it thicken.

 

15W-40 is 15 weight base stock which has coiled-up thingies added which uncoil when hot. When uncoiled, they increase viscosity enough to make it behave like 40 weight. The downside is that they also degrade over time, and the oil loses its ability to make its higher viscosity.<br><br>The Mobil website used to have a good article about this.

 

Yes. The SAE rating of &quot;W&quot; is for &quot;Winter&quot;, not weight. Against popular belief.

 

Gotta love these technical discussions. &quot;Thingie&quot;? Just kiddin', it's almost my favorite word when I can't think of the right word.<br><br>~Dave

 

How about these Dave ? whats-ya-maycall-it, do-hinkie, thing-amay-bob, thing-amay-gig, bring back any memeries.<br> I worked with an old timer that used those words all the time.<br> Some of the boys actually got to know what he was refering too, funny as heck. He would usually start the words with a doggone or dadburn. A great guy but very funny.

 

[quote author=GONZO link=board=8;threadid=5925;start=0#55030 date=1035043359]<br>In Texas we have the Chinga -Dera. That covers everything. <br>[/quote]<br><br>Yeah, I remember that one from awhile ago. Still don't think I ever got a good meaning for it. So, obviously, it's one of those whatchamacallits. <br><br>~Dave