Delo 30wt Best (with an engine blanket ) ?

[1sttruck]

http://www.eaa49.av.org/techart/str_oil.htm

Last March, a pair of Mercedes-Benz Engineers (Rudolf Thom and Karl Kollman)along with pair of Shell Oil engineers (Wolfgang Warnecke and Mike Frend)wrote an SAE technical paper (No. 951035) on "Extended Oil Drain Intervals: Conservation of Resources, or Reduction of Engine Life?" Among the many interesting results presented in the paper was a graph showing cylinder-wall wear-rate Measurements correlated with cylinder wall temperature. Cylinder wear rates(in micrograms per hour) were monitored as a function of cylinder-wall temperature in a test engine specifically fitted with radionuclide-impregnated cylinder liners. Three test were done so that three different kinds of oils could be used. In one test sequence, a straight 30 weight oil was used; in another, 10W-30 multigrade; and in the third, straight 10 weight oil. (The test engine was a Mercedes-Benz OM 616 2.4-liter, 4cylinder diesel.) In each case, the engine was operated at fixed speed, torque and temperature conditions until constant wear rates were observed. Wear rates were then plotted against cylinder wall temperature.

The graph of cylinder-wall wear rate versus cylinder wall temperature tends to be bathtub-shaped, with wear increasing sharply at each temperature extreme (as you'd expect). But while two of the oils turned in very similar wear performance, one oil stood out as protecting the engine against wear at the extremes of temperature. That oil was plain SAE 30 (Straight-grade 30-weight). At either extreme of temperature, the maximum wear rate with 10W-30 was more than double that of the straight SAE30 oil. (The worst performance was turned in by straight 10-weight.)

 

[DR Racing]

I would have to agree with your title straight weight is the best if you never let the engine get cold. Dan

 

[Eddie]

How can we get the graphs? How does the amount of materal removed vs temp relate to engine longevity? You mentioned wear increasing sharply at tempeture extreams. This is the reason for multigrade oils. The area under the temp/time curve and the engine running time at each tempeture is the deciding factor in determining "best over all" oil viscosity. From you comment about 30 wt being the best may be misleading for the engine who spends 10 minutes coming to full tempeture and only 5 minutes at full tempeture. I have forgotten differental equasions long ago so maybe someone can calculate from the bell shaped plots what this really means in the real world. anyone??

 

[Gary Allan]

Isttruck, what was the wear for the 10 weight as compared to the 30 weights in pre-warm up conditions? That is, was 10 weight superior at any point in the test? Was it a true 10 weight ..or a 10w? Effetively a 10w-20?? This also makes me wonder why the relatively sensible comparison between 30 weight and 10w-30 ..and such an extreme deviation to 10 weight. Why not straight 20 or 20w-20?

This should have been tracked ..since all formed a bathtub curve.

What agenda does this SAE paper further??

[ June 10, 2005, 04:55 PM: Message edited by: Gary Allan ]

 

[lewk]

fwiw gary I would question the rating of the 30w oil as well. it very well may pass as a 15w30 or a 20w 30.this confirms what I have believed and is the reason the use of mongrades for top off is a good idea.some 30wt monogrades demonstrate very good viscosity at 40/100c and is better than most 5/15w40 oils(40c only).if you use a 5w30 or a 10w30 this may be a viable substitute in warmer climates.hths values are better too.for commercial use or towing would this be a positive step?

 

[1sttruck]

In another thread Ted (I've been referencing him a lot in the last few days, threads passing in the night I guess :^) noted that one needs to initially pay attention to the 'winter' weight since that is effectively the base oil, until it is demonstrated how shear stable the oil is.

Another 'take away' from the article is that 'thicker is better' for reducing piston wear, but that's simplistic as they didn't bracket the oil that worked best with a heavier one.

The article also questions the current wisdom touted around here about thinner oils working better at start up. Thinner oils may get oil flow or pressure up quicker, but per this article and per other comments on the use of single weights in aircraft they lose to single weights since the single weights leave more oil on surfaces and start off thicker. It's be nice to see some more specific data, but I won't be buying the SAE paper.

 

[Steve S]

Straight weight oils perform awesome .

 

[DR Racing]

Where have folks on this board seen delo SAE 30 for sale in the stores? I can only find at a local truck fuel and oil supply depot for $10 a gallon. Dan

 

[ediamiam]

autozone - under $7.00

 

[lewk]

el centro ca has an oil ditributor that sells st.30w delo and delo 10w30 in 12qt cases and 5 gallon drums too. I cant find the no. or recall the distributors name.help!

 

[Mamala Bay]

Chevron

List of Chevron Distributors.

I believe that Delo 400 is being reformulated and will be available in Sept 2005.

 

[Mamala Bay]

The Delo has the moly and it was reformulated.

 

[Audi Junkie]

Here are some of the products listed at a local Chevron dist:

CHEVRON DELO 400 MULTIGRADE SAE 15W40
Chevron Delo 400 multigrade heavy duty motor oil is an exceptional, super premium quality "universal" engine oil (which exceeds industry and engine manufacturer's performance requirements) recommended for all 4-cycle and 2-cycle diesel engines operating under severe service.

CHEVRON DELO 400 SYNTHETIC SAE 0W30-5W40
A multipurpose synthetic lubricant formulated for use in gasoline and diesel engines, torque converters, gear cases, and hydraulic systems operating in sub-zero Arctic-type temperatures.

In additiion, I saw 5w-50 Chevron Supreme Synth!

No mention of the 10w-30, 5w-40 sounds great for summer...0w-30 in winter.

How much do I need to purchase is the question. A palette seems a bit too much..unless we get a gruppe buy going.

 

[DR Racing]

ediamiam, Thanks I found it at AZ. They keep the diesel oils in a different place in the store. I did not see any 10w-30 delo though darn. Dan

 

[Akiba]

haha, so this topic was dead many of days/month ago till i came along. i've thot about throwing st-30wt into my 91 car that i rarly use just to see how it goes about things. i really wanna try this out in my 4.3l that's inside of my 99 s-10 ~~~ just because i love to try out things that other ppl dun i guess. so wut's the deal? anyone think itya be a worth-while thing to do? would the 30wt be better in the long run? where i live the summer temps are 100+ and winter temps are 30F sometimes lower.

"Straight weight oils perform awesome" by Steve S

Really now ~~~ I never hear ppl talking of it thoe.

Akiba

 

[JAYCEE]

Carquest sells Delo 400 SAE 30.

 

[2004 F150 4x4]

Wow !! They needed a test for that. I could have picked the winners by order 20years ago based strictly on my own experiences/observations!!!

 

[TooSlick]

A straight weight lubricant uses a higher molecular weight basestock, hence it provides improved protection against scuffing wear @ high shear rates. These fluids are still very popular for constant rpm, piston aircraft engines, generators,EMD's, Marine engines, etc that function within a narrow ambient temp range.

Most PAO and/or Ester based, 5w-20/10w-30/15w-40/20w-50 lubes can be thought of as straight weight oils, that pump well enough at low temps (due to their high VI's), to meet the SAE J300 specs for 5w/10w/15w/20w oils.

I'm sure the SAE 10w-30 used in this test was a conventional fluid. In which case it's most likely a 4 Cst, 115-119 VI,Group II basestock that's "jacked up" with polymeric thickener, to meet the 30wt viscosity @ 100C.

 

[416Rigby]

Where can you get Delo 400 synthetic online? Thanks.

 

[Big O Dave]

The technical paper cited, No. 951035, was published in 1995, which was before hydrocracked base-stock became common.

Just a point to consider...