Delvac 1 5W40 in Duramax ?

[smitty8401]

I am interested in switching to a synthetic oil in my 02 GMC 2500HD
W/Duramax. I have heard good things about Mobil's Delvac 1 but my local dealers are telling me that I shouldn't use it in my
truck because it is a 5W40 and the Owners manual recommends a 15W40. They claim that if I use anything but a 15W40
it will void my warranty. All I want to do is whats best for my engine. Do you know if I can safely use the Delvac or
should I look for a 15W40 motor oil?

Thank you,
:confused:

[SteveO]

smitty8401,

It's absolutly ok to use in your DMax.. I have used it mine for 2 years and never a problem..

It meets all Dmax Sae ratings...

If you look in your DMax Owners Manual it clearly states that 5w-40 can be used.. The book has a chart with 5w-40 going up the scale just as high as the 15w-40...
It even states that if the Ambient temps are 0 and below to use 5w-40...

[mackin]

SteveO your a busy guy tonite!!! ;)

AH the dealers so much fun they are....See if they can explain this.....

=>Diesel Engine - Correct Oil Viscosity & Oil Filter Usage


Bulletin No.: 00-06-01-025A

Date: September, 2001

INFORMATION
Subject:
Correct Oil Viscosity and Oil Filter Usage for the Duramax 6600 Diesel Engine (RPO LB7)

Models:

2001-2002 Chevrolet Silverado and GMC Sierra 2500 HD and 3500 Models with 6.6L Engine (VIN 1 - RPO LB7)

This bulletin is being revised to add the AC Delco oil filter part number and add the 2002 Model Year. Please discard Corporate Bulletin Number 00-06-01-025 (Section 06 - Engine/Propulsion System).
Important :The Duramax 6600 diesel engine can produce oil pressures over 690 kPa (100 psi) during a cold start condition and the oil pressure gauge may remain near 552 kPa (80 psi) while driving. Because of these oil pressures, it is important that the correct oil filter is used and torqued properly and the proper oil viscosity is used for the ambient temperatures.

Oil Filter

The correct oil filter for use on the Duramax 6600 engine is the AC PF2232 or the production oil filter, GM P/N 97214983. This filter was designed specifically for use on the Duramax 6600 engine and incorporates improved filtering capabilities as well as an integral oil pressure relief valve. The oil filter should be torqued to 24 N.m (18 lb ft) to prevent leaks under high pressure conditions.

Oil Viscosity for Cold Weather Operation

SAE 5W-40 viscosity oil designated as API CH-4 or CG-4 should be used if the ambient temperature falls below -18

[HDLD]

No wonder there is so much confusion out there. Tonight I was reading some .pdf's and found each of the two below have a final paragraph called "Precautions". I have quoted the first line from each of these paragraphs:

http://www.mobil1.ca/pdf/mobil1supersyn.pdf says:

"Mobil 1 is manufactured from high quality synthetic base oils" while,

http://www.mobil1.ca/pdf/delvac1.pdf says:

"Mobil Delvac 1 is manufactured from high quality petroleum base stocks"

Meanwhile, the same Mobil Delvac 1 pdf file starts off stating:

"Mobil Delvac 1 Synthetic high performance diesel engine oil contains high-quality synthetic base stocks and a unique component additive system."

Notice it doesn't say manufactured from high-quality synthetic base oils or stocks.

This would lead me to believe it is not a true synthetic. Perhaps this has been discussed elsewhere. Does anyone have any definitive information to that effect?

[ 01-16-2003: Message edited by: HDLD ]</p>

[TraceF]

Every synthetic lubricant is derived from hydrocarbon (mineral) based crude stock.

In lay terms synthetic means to synthesize (alter mother nature's) molecular structure of the crude when formulating a base stock.

Still comes from dino.

Delvac 1 is a PAO G4 base stock. This is the current highest grade of synthetic base.

[HDLD]

TraceF,

Ahhh...I think I'm finally starting to see the light albeit a dim one yet...

I still don't get why they make the claim then that the Mobil 1 is made from synthetic base oils. Is that because this particular product is doing just that (although that synthetic base oil had to have originally been taken from hydrocarbon) and then they are adding their supersyn additives.

I guess I just had this mistaken belief that the better "true" synthetics were made entirely in the lab and no hydrocarbons were involved. We really need a good FAQ on this topic. If this is the case (need hydrocarbons), then how much hydrocarbon base is used to produce a quart of synthetic oil and how does this relate to lessening demand for crude? 1/20, 1/4, 1/2?

[Toddster]

Trace, pal, I have to diagree with you on this one ! The whole basis for Molil's lawsuit against Castrol was because of Castrols "hydrocracking" process of dino base stock and then calling it a full synthetic. From my understanding Mobil 1 IS produced in the lab....No dead ancsestors involved.

[george morrison]

There was a mis-post a while back on the internet listing for Mobil Delvac 1. It was there for 7 hours only. Yet it somehow still manages to surface.. Delvac 1 is pure 100% Group IV PAO. Has been for 20+ years and still is today. It has gone through evolutionary refinement, improvement but still same full, real synthetic concept.
The 5W-40 full synthetic discussed in the owner's manual IS Delvac 1.
George Morrison, STLE CLS

[Seattle Steve]

Smitty 8401- Another way to look at this is that Delvac 1 performs as a 40 weight at normal temps (the "-40" part) and as a 5 weight at winter temps (the "5W" part). In other words, similar operation at normal temps as the 15W-40 and less likely to thicken in winter. Mackin gives great info on the mfgr's position and based on the reputation of Delvac, I intend to use it after break in.

[indydmax]

I'm throughly convinced that Delvac 1 is the oil of choice. When I first purchase my truck I used Delo 400 ( I think that is the correct number ) and changed the oil every 2.5K. My truck would have the dreaded "tick-tick-tick" most of the time. Based upon conversation in this forum, I switched to Delvac 1300 mainly because I could not find Delvac 1. The dreaded "tick-tick-tick" only lasted for the first 500-1000 mile after an oil change. In the meantime, I have found Delvac 1 and use it on a regular bases. The "tick-tick-tick" is completely gone. I can not state for certain that the oil is the cause of the "tick-tick-tick"; however, in my mind I believe the Delvac 1 remedied
the problem.

[TraceF]

Todd- I thought the Mobil-Castrol suit was a formulation/advertising issue. The following is taken from ExxonMobil's website:

&lt;&lt;In the late

[george morrison]

Regarding your comment "It is true that Mobil 1 and Delvac 1 are and always were PAO synthetics, but the Group IV (and I, II, III,and V)designation wasn't adopted until 1989 if memory serves me correctly." Your memory serves you perfectly. Mobil 1 and Delvac 1 are essentially the same PAO base stock lubricants as introduced 20 plus years ago; however both have undergone evolutionary chemistry refinement since introduction. Same name, same base stocks but both product lines superior in every measurable parameter compared with the initial products. For historians, the original Mobil Delvac 1 was a 5W-30 viscosity! Back then diesel engines ran straight 30W. I have one of those original Delvac 1 30W jugs sitting on my desk.
George Morrison, STLE CLS

[TraceF]

Regarding synthetic lubricants formulation- I found this very informative article and sent e-mail last night to the author. His response is added below the link to the article.

http://www.scienceinafrica.co.za/2002/november/lubes.htm

I wrote:

&lt;&lt;I read your article. Simple question- do ethylenes, esters, and polymers that go into PAO base stocks come from hydrocarbons?&gt;&gt;

His reply:

&lt;&lt;Dear Sir,

Thanks for your question. Yes, the ethylenes esters and polymers are all made from petroleum feedstocks. The range of hydrocarbon to be used depends on the product to be manufactured and the carbon number required. Esters are not directly produced from hydrocarbon but they come from higher carbon number range which are first converted to synthetic fatty acids then to esters by reaction with appropriate alcohols. I hope this will answer your question.

Kindly identify yourself with full details.

Regards,

Dr Himmat Singh&gt;&gt;

When I sold and trained others to sell lubricants we used to make the analogy that comparing synthetic base stock to mineral base stock is like comparing a bucket of BB's to a bucket of sticks and rocks. The reason the synthetic stock makes a better lubricant and gives better heat and cold protection and performance is because the molecules have been rearranged in a fashion that allows many more of them to be in a given area, between bearings and races for example. The formulations are also designed to be "sticky". They adhere to metal better than mineral base stock.

I use synthetic lubricant in my rear diff because I tow a heavy load and the diff doesn't have a cooler. I live in Florida so cold weather protection is no real concern. The engine, with 10 quarts of premium quality CI lube is regulated very well in terms of operating temp and therefore I chose not to spend the extra $ on synthetic, I don't believe the synthetic offers any significant benefit in this application.

My $ .02

tongue.gif tongue.gif tongue.gif

[ 01-19-2003: Message edited by: TraceF ]</p>

[TraceF]

Hey George-

Were the original jugs plastic? I like the current jug, easy to work with.