Delo 400 vs Delo 600, vs Delvac 1300

[Fahrvergnügen]

15W40/ 10W30 Conventional for H.E.U.I. Injector Diesel engines. 10W30/ 5W40 Synthetic for a Common Rail modern Diesel, 15W40 Conventional if Common Rail is used in high heat conditions and high load is fine also.

H.E.U.I.'s will shear 5W40 Synthetic fairly quick. 15W40 Conventional does not shear too much, it will shear down to a 30W over a much longer time frame.

I use Delvac 1300 in a H.E.U.I. 7.3L cause I get it so cheap. I have ran the old school Delo 400, 15W40 Conventional when I was doing some Hiway long hauls for 10K miles, no problems. That oil does not exist any longer.

P.S. You can't find Delo? Its the most commonly used oil of all the companies I have worked at that did transportation for over 35 years.

Eta, Have you tried big truck repair and parts houses, you might have to buy a 5 gallon pail at worst.

A 6.7 powerstoke running 15w40 is not good. It will ruin the main bearings and rod bearings due to the oil system routing. It takes a long time to flow to the top of engine already, add 15w in the mix and it causes premature wear regardless of climate. Only time 15w should be used is if b20 is used due to the dilution issue that arrives with b20. At my dealership we asked the customer if they carry weight, tow or do they just drive it around. If towed motor craft 5w40 went in, if they drive it around 10w30 was used. Never 15w40. I’m in the south hottest and has most humidity out of anywhere in country.

 

[bismic1]

I worked at ford and can tell you less injector issues with 5w40’s as well with the 6 liter. Sticion is a problem with 6 liter and 7.3.

I agree.

I have been going 7500 miles on oil changes w/ 5W40 oil in my 6.0L for quite a few past oil change intervals. Probably dropping back to a 5000 mile OCI since I only drive around 3000 miles a year in it now.

At the 7500 point, the viscosity of my 5W40 oil has just dropped to what a typical 10W30 starts at.

I am always amused at people saying to not use a 5W40 oil BECAUSE it will shear to a 30 weight ........ and in the same sentence say to START with a 30 weight!

I am still operating the original injectors at 243k miles (been using 5W40 for 228k miles). No smoke. When I get to 250k, new ones are going in though (I believe I will improve fuel economy by a mpg or two with new injectors).

 

[Brons2]

This is not the case for HEUI. The 5w40 full synthetic is better for the oil pressure driven fuel injection. And the 5w40 totally eliminates sticion. Here is an article.

That is not borne out by UOAs. And most people who have these say the 5w40 shears down to a 30wt in short order, especially in the 6.0s. YMMV.

 

[kschachn]

That is not borne out by UOAs. And most people who have these say the 5w40 shears down to a 30wt in short order, especially in the 6.0s. YMMV.

It’s not borne out by anything. That is a factually incorrect post based upon absolutely nothing. The poster has no idea what he’s talking about and has no idea what a winter rating represents. We’ve seen this here and in other threads.

Same poster that claims he works for BMW, but actually works for a dealership.

 

[bismic1]

That is not borne out by UOAs. And most people who have these say the 5w40 shears down to a 30wt in short order, especially in the 6.0s. YMMV.

I'll say it again (data driven - 45 UOA of mine, quite a few more from other people) - my UOA on my 6.0L shows that multiple 5W40 oils do not always shear to the 30 wt category in 5000 miles. I have multiple threads in the Diesel UOA section on that (data posted). Even going 7500 miles doesn't always take it to a viscosity less than where a 10W30 starts out at (exception - Valvoline PBE). People that say a 6.0L shears a 5W40 "in short order" not only fail to define what "short order" is, but also are probably just reciting internet generalizations (inaccurate ones at that). Also, I will say that at 243k miles, I have NEVER experienced stiction. The first 15k miles were on 15W40, the last 233k miles on multiple 5W40's (Delvac 1 ESP, Mobil 1 TDT, Valvoline PBE, Rotella T6, Schaeffer 9000). According to my engine data the PBE sheared more quickly than the others.

Anyway, what is wrong w/ a 5W40 shearing to a value close to where a 10W30 starts at 5000 miles (btw - Rotella 10W30 starts at 12.0 cSt)??? Especially when it isn't much below that value (if any) at 7500 miles? Except for the PBE and several runs of other oils with Archoil 9000 as a data gathering experiment, my viscosities were almost all 12.0 or higher.

I have nothing against a 10W30 and I would be confident that it does well w/ the 6.0L "stiction potential". There are posts on a couple of 6.0L diesel forums showing its viscosity to drop to 10.5 cSt at 5500 miles and even to 9.7 at about 8000 miles. That's close to a 20wt in what some people seem to call a "short order".