View Full Version : motor oil question
10-15-2002, 07:06 PM
at operating temperature what is a thicker oil 30w or 15w-40?
10-15-2002, 07:25 PM
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-
10-16-2002, 08:40 AM
10-16-2002, 10:00 AM
Makes note to skip class tomorrow. ;D ;D
10-16-2002, 01:15 PM
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)
10-16-2002, 05:33 PM
(note to self)<br>Call in with vision problems tomorrow. Just can't see going to class.
10-17-2002, 08:25 AM
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. :D<br><br>Trying to hide behind Jack since dd4x4 has a better excuse than either of us ~Dave
10-17-2002, 09:13 AM
so the "W" stands for Winter not weight right? At least that's what it says on the valvoline page! ;D
10-17-2002, 10:28 AM
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.
10-19-2002, 12:24 AM
Yes. The SAE rating of "W" is for "Winter", not weight. Against popular belief.
10-19-2002, 08:59 AM
Gotta love these technical discussions. "Thingie"? Just kiddin', it's almost my favorite word when I can't think of the right word.<br><br>~Dave
10-19-2002, 09:39 AM
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.
In Texas we have the Chinga -Dera. That covers everything. [laugh]
10-19-2002, 08:37 PM
<br>In Texas we have the Chinga -Dera. That covers everything. [laugh]<br><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. [laugh] [laugh] [laugh] [laugh]<br><br>~Dave
10-20-2002, 08:58 AM
Donít forget them osolators that fit on the resuscitators. You know them thingys that keep the backup gears from getting hung up in the reverse cogs? ???
10-20-2002, 03:21 PM
Only problem is that every "thingey" displaces actual oil for less actual lubricatiing capacity. Years ago the engine manufacturers recommended straight weight oil for this reason. Polimers reduce lube capacity. Don't know about synthetics, they may have corrected this problem. I guess the engines of today are built for these oils in contrast with the earlier engines.
10-20-2002, 04:56 PM
Hauling- It's true that the VII polymeres don't have any lubricity themselves. But they make the oil stay in places it would otherwise leave. Any manufacturer has to balance the runtime of an engine with the cold starts. On a cold start you need thin oil to get it to the places fast. When the engine is warm the single grade oil would be better. Modern engines are sometimes even designed to use these qualities of the oil. EG timing chain tensioner on BMW 4bangers. If you think you do your engien something good by using 5W40 instead of 10W40 the chain can start to oscillate and even tear off. Personally I do use the oil the mfg recommends. (They used up a bunch of engines to find out )<br>AlpineRAM
10-20-2002, 05:16 PM
Alpine I run Delo 400 15/40 in the Dodge. In the old Detroits I ran Delo 400 40 weight.
10-21-2002, 04:24 PM
These engines are so good, why do we even NEED oil??? :o
10-24-2002, 10:04 PM
<br>These engines are so good, why do we even NEED oil??? :o<br><br><br>For the same reason that you have to feed a woman ;D
10-26-2002, 01:06 AM
<br><br><br>For the same reason that you have to feed a woman ;D<br><br><br>Good One...I like that. Just don't tell the little woman! ;)
10-28-2002, 09:59 AM
Feed women ???
Hmm maybe that's what went wrong in my relationships ;D
;D ;D ;D ;D
10-31-2002, 11:00 AM
I'm a brand new diesel owner and brand new to this site. Just bought a 1995 Ram Laramie SLT 4x4, automatic, and just love it. I pull a 32' 5th wheel (old timer 1979 Kountry Aire) and love to camp. My wife and I plan on going around the country as soon as we retire (4 years). About the oil thing, a friend of mine says to use the Shell Diesel Oil and nothing else. Whats the general opinion.<br><br>Thanks<br>Bill
10-31-2002, 11:14 AM
Welcome to the site. You will love your new/old truck. As far as oil goes there are alot of answers. Lots of people use Rotella T and have no problems even with 500k+ miles on engine. I use Valvoline Premium Blue(I think that's what it is). It is the full synthetic and can be purchased at most auto parts stores or truck stops. Funny thing is you can actually purchase it cheaper than regular oil. Doesn't make sense to me but I am not complaining.
11-04-2002, 11:28 PM
I myself use Amsoil in everything, time will tell if it's been worth it.<br><br>Later, Rob
About the oil thing, a friend of mine says to use the Shell Diesel Oil and nothing else. Whats the general opinion.<br>I think the Delo is slightly better than the Shell (Rotella), buuut, another factor to consider is what was the previous owner using???<br>I'd seriously consider just continuing to use the exact same thing, provide it meets the minimum requirements found in the owner's manual.
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