Delvac 15w-40 for winter use?

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Jun 6, 2003
Petersburg, West Virginia
I think the pour point for the delvac is around -33f. Do you think this would be adequate cold weather flow. Or would the 5w-40 shell group 3 be better. The only delvac on the shelf at my local walmart is the 15w-40 but they do carry the rotella 5w-40. This would be used in a 350 vortec with 128000 miles. Here in West Virginia we can see temps. as low as -10 to -15f. Any help would be appreciated.
For temps that low I'd have a hard time recommending 10w30 oils to someone, let alone 15w40. The engine might just not start if the battery is not in 100% shape.
That Delvac 1300 wouold be pushing it. I'm north of you and used the Rotella this past cold-cold winter with no problems.

So Patman even a good synthetic like amsoil or mobil 10w-30 would not work

No, these would be ok. I'd run a 30wt 5w/10w-30 in the winter time. WV gets very cold.
Like a rock, Their two factions in the oil viscosity world. New Age thiner viscosity nuts and Old School thickest for temp school. I would not use Delvac 1300 15W50 in the winter. I would not hesitate to use a group III,IV, or V synthetic though in 5W40,10W40 or 10W30. Short of anartica you will never see me recomend anything lighter then 10W30 even synthetics. If someone else mention synthetic 5W30's I will conceed that they have been shown to be almost as effective as synthetic 10W30. My Dad runs M1 15W50 year round wich I will not do.The M1 15W50 flows as well as a conventional 10W30 in cold weather. He has yet to have a cold start oil flow problem and he is at 200,000 miles uses no oil and runs like a top. We had to have it apart this year to replace one of the timeing chain tensioners. We live in Michigan so we see some cold weather. I think that the 5W40 Rotella T Synthetic would serve you well.I might also point out that you have 6 months before winter comes! Mobil 1 15W50 has the following propertys:Typical Properties

Mobil 1 15W-50

SAE Grade 15W-50
Viscosity, ASTM D 445
cSt @ 40º C 125
cSt @ 100º C 17.4
Viscosity Index, ASTM D 2270 153
Sulfated Ash, wt%, ASTM D 874 1.3
HTHS Viscosity, mPa·s @ 150ºC ASTM D 4683 5.11
Pour Point, ºC, ASTM D 97 -45
Flash Point, ºC, ASTM D 92 230
Density @15º C kg/l, ASTM D 4052 0.864

Compare that pour point to a conventional 5W30 or 10W30. Also check out the HTHS number!!!! You can get the 15W50 on sale at walmart right now $18.99 for 5 quart container!

[ June 08, 2003, 09:28 PM: Message edited by: JohnBrowning ]
I've seen here before you would recommend using Redline oil if $ were not an issue. I drive a 95 Toyota 4x4 w/22RE motor. It has 129,000 miles. I've finished 2 Auto RX treatments and it really didn't help in the oil consumption, which is about 1qt. per 3,000 miles. I have some Redline 10W30 to use but was wandering about the 15W50. What are your thoughts?

Originally posted by like a rock:
So Patman even a good synthetic like amsoil or mobil 10w-30 would not work? There pour points are well below the lowest temps. I would see.

A good 10w30 synthetic would work well, just not a 10w30 conventional. I'd still recommend going with 5w30 or 5w40 synthetic in the winter though, you might as well do everything you can in order to get faster oil flow in extreme cold.
RandoI think I mentioned that I also have th 22RE ('94) my oil consumption is about the same. I mix 25% M1 15W-50 and it cut the usage down. I would just mix the M1 15W with your Redline. Could be a good thing with all of the Esters. Only potential problem could be seal leakage by using the two. However since individually they have seal neutral compounds it should be OK.

I have the Rotella 5W-40 syn (Group III) in right now and after 1500 miles there is very little usage. I only put about 4-5 K miles on the truck per year so it gets one change per year. Whether it needs it or not
Viscosity at temp. is more important than Pour Points. That said, the cold start figures are a guide, with synthetics providing a safety margin.

A 5 weight is certified to start at -30C (-22F)..and a 15 down to -20C (-5F) if your temps are below -5F, it will be a tough start with a 15 weight and I wouldn't recommend using this weight...especially when the conventional Delvac is in question...
My thoughts are free so here you go. Redline formulates on the thick side. So your choice of 10W30 is the best choice to start with. With redline if you do not live some place really hot like FL., GA., TX. then stick to 5W30,10W30, 5W40 and 10W40 and leave their 20W50 alone. Their 20W50 is really for people that race their daily drivers or 4 wheel in a high load low speed situation. I would not consider 1/2-1 qt. per 3000 miles to be abnormly high in a vechile.1/2-1 quart is perfectly acceptable. The Redline is shear stable, will clean the engine of any remaining third party abrasives and should cut your usage in 1/2 if you current usage is volitility related. If Redline does not cut your consumption then you have a mechanicly problem that is causeing the oil usage. If you have the redline already give it try. You should be able to run it out to 7500 miles no problem then test it. M1 15W50 is also a good product( It is what I use in my new truck) and the price is right. THe problem though is that M1 as good as it is is alot more volitile for any comparable weight of oil as compared to Redline and the HT/HS number are also not as good. If Redline does not solve you oil consuption issue then none of the other synthetics is likely to either. I just figured you might as well cut to the chase. If Redline does not work then you can save your money that you would have spent on Amsoil and Royal Purple and go right to M1 which is best value in a 100% synthetic oil.
Dr. T, I couldn't have said it better. Are we all looking at the wrong numbers? Sure, pour points mean something, but what about the cold start viscosity tests.

I see oils that have nearly the same pour points in a 5w30 and a 10w30, but then show the 10w30 having the same viscosity at a point 5 degrees higher than the 5w30's. Does that not indicate that the 5w30, despite the same pour point, is much better at colder temps?
MNgopher, I was useing what I had available from Mobil1 site. They did not list cold crank that I could find so I could not provide it. You will also note that I did not recomend useing M1 15W50 dureing winter. I mentioned that my Dad has done it for 200,000 miles on his truck. P.S. What is the cold crank for M1 15W50 and most 10W30 convetional oils?
Ahh yes, the infamous different or lacking data problem. Makes it so dang tough to comapre oils based on Tech data alone...

10w30 has to pass with less than 6000cP at -25 C. Most dinos are right in the 5500-5800 range.

5w30 has to pass with less than 6000cP at -30 C. Again, most dinos come in just under this limit.

I can't find my handy chart with the other passing numbers, but it would stand to reason that the 15w is probably done at -20C.

Don't get me wrong - pour point has a place (especially as it relates to borderline pumping temperature), but I'm not sure its the ultimate guide.
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