Qs re: TDT vs. Rotella T6 vs. Delo 400 in summer

Zambee500

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Atlanta, GA
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2005 Passat TDI GLS, 2014 NMS Passat TDI SEL Premium
This might be a risky thread to start, but here goes: are these about equal for a PD motor in the summer, or which one of these would be better for high ambient temperature use? From what I've gathered here over the years, T6 is a bit thinner than TDT and it makes T6 a great choice in the winter up north for cold start-ups, as well as marginally better MPGs with T6 than TDT. And TDT gets the nod over T6 for longer drain intervals (although T6 is fine for 10k miles).

Does that mean conversely that TDT, being a bit thicker, would be better in the summer in the South with high outside temps? I noticed Shell advertises T6 specifically for high-temp operation, but not sure what to make of that so I thought I'd ask the experts. For the past several years I've run T6 in the winter and TDT in the summer, and then whichever in the shoulder seasons. Just double-checking that philosophy as it's time for another oil change and where I am we've got 2 more months of 90+ degree weather.

Also, how do the characteristics of Delo 400 LE compare to T6 and TDT? On the thicker or thinner side? And 10k vs. extended OCIs? Other differences?
 

Bob_Fout

Oil Wanker
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Indiana
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2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
1. Yes
2. Pick any of the three.

Your oil does not get to high temps unless you are on the track and have lots of mods. Otherwise, oil temp is regulated (oil/water heat exchanger).

The "thick" vs. "thin" aspect of T6 vs. TDT is in cold weather only (below 25*F or so). All three are close in terms of 100C viso and HTHS.

Stick with 10K/1 year intervals unless you have UOAs to show it can be extended.

Pick whichever is cheaper or which company you wish to support (Chevron, ExxonMobil or Shell)
 

Zambee500

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Thanks, Bob. I suspected about as much.

I don't have any mods except a stage2 cam replacement, if you can call that a mod. When I had that done it sounded like it was the hot, outside ambient temps that really accelerated the cam wear; hence my questions.

I've got a quart of TDT leftover, so I can get by with just a 1 gallon purchase for next oil change. So even thought TDT pricing has spiked compared to the Delo400 LE and Rotella T6, for now that would be most cost-effective in the short term. Hopefully we will also see some UOAs of the Delo in a PD motor before my next OCI.

Thanks again, Bob.
 

Maffken

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99.5 A4 Jetta ALH
My ALH hasn't had any starting issues save for old glow plugs and a failing battery (Possibly a starter, but it stopped making noise) with T6 and I've started it down as far as 12 Fahrenheit.

Lower than that and I just don't want to go out ;). Plus it's been abnormally warm most of the last few years.

I don't have a PD but I'm inclined to keep using T6 just to make it easier on my wallet (I can sometimes get a discount on it + I've got some leftover). I might spring for something thicker If I lived somewhere warmer (90+f like GA/ 5w40 instead of 5w30) but I really don't see a 10 difference in weight making much a difference, at least until you get into really cold winters; I doubt you'd even get cool enough in GA to justify it anyways to be honest. Cold to me is 23-5f and below, above that I doubt any real issues.
 

Zambee500

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I'll double-check the Schaeffer. There are 3 resellers in my "commute zone" so I will call them to see how they have it priced. In the past, it's been priced a good bit higher than Pentosin HP2 and LiquiMoly Diesel High Tech, so I never could justify Schaeffer over other options. But I'll see where it's priced now locally. Thanks for the suggestion.
 

Zambee500

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In my area T6 is more available and cheaper per gallon than TDT.
About a $3-4 difference where I am, unless you can find a M1 sale going on and can sneak the TDT past the cashier as part of the sale. And Delo 400 LE is $2 cheaper than T6. But I need 4.5 qts for an oil change, and another 1/2 - 1 qt. for topping up throughout the OCI. So in my current situation that's 2 gallons of T6 or Delo 400 or 1 gallon of TDT (to go with the leftover quart+ I already have). I generally don't like mixing oils, although I know there are 2 camps of thought on that issue.
 

Bob_Fout

Oil Wanker
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Indiana
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2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
I too wish quarts of Delo 400 LE 5w40 were readily available like quarts of T6 and TDT are...
 

Cursed_9d8

Member
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Apr 22, 2013
Location
Central Oregon
TDI
1998 Jetta TDI
I have run all 3 of these oils in my Jetta, trying to find the "best one" for my money. They are the only 3 brands readily available in my area. These are just some quick notes on the differences I noticed from the driver's seat....

I started with Rotella T6, as recommended by the VW mechanic who replaced my engine -
*Easy cold weather starts
*Quiet engine operation
*Limited smoke, only during cold starts and extreme heavy load conditions
*MPG 46-48 average
*Oil consumption < 0.25 qt every 1,000 miles
The better all-around product, IMHO.

Mobil 1 TDT -
*Engine operation much more quiet than the T6
*More difficult winter starts
*Smoking somewhat excessive during extreme cold or hot temps and during heavy load conditions
*MPG 45-49 average
*Oil consumption approx 0.5-0.75 qts every 1,000 miles
I like Mobil 1 oils and I use them in all my gas cars, but for the extra coin and the other minor drawbacks I experienced, it's not the best choice for my TDI application.

Delo 400 LE -
*Engine noise greatly increased, mostly during hot conditions (drive thru attendants have asked me to turn off my truck, and passengers have asked me "Is that noise normal?")
*Easy cold weather starts
*Some smoke at start up and during heavy load conditions
*MPG 42-47 average
*Oil consumption, 0 after 5,000 miles!
It's the least expensive option and I haven't had to buy any additional, but the noise is not worth listening to.

For what it's worth....
 

Henrick

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Aug 24, 2010
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Ireland
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Golf VI TDI, 77 kW (CAYC)
Mixing chemistry "summer oil" "winter oil" again and again might introduce more harm than a potential benefit.
 

James & Son

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Maryhill, Ontario, Canada
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2006 Jetta
Are we all brain dead here. Like he said for whats its worth. I say its worth very little to adding to the knowledge we need to gather on this web site.

Oil consumption is the dead give away. The hths of T6 is 4.0, TDT 3.9 and yet T6 is the break in oil and has less than half the oil use per 1000 miles. Did he all of sudden switch to Biofuel or something. Now Delo goes to 0 per 1000 miles, not only that it is 0 for 5000 miles!
How can delo be louder than T6. Most diesel knock(noise) is generated by combustion and not the cam with hydraulic lifters, so was Curse fooling around with his timing. The only other thing would be the amount flow of oil and the thickness of the flow of oil in the cylinder head that might have a sound deadening affect. But the differences in these CJ4 oils is only in the additive package, the delo having lots of boron and moly and the others having much less. Delo has 550(edit actually 65) parts of boron, how does that make it loud.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1157741 edit: see pg 2 of this thread for proper VOA and UOA

Edit: I suggest that his oil sump is filling with biodiesel or fuel diluting and that is why he has zero oil consumption and his viscosity is water thin and that could be a more likely reason for the load noise.
 
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Bob_Fout

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Location
Indiana
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2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
Are we all brain dead here. Like he said for whats its worth. I say its worth very little to adding to the knowledge we need to gather on this web site.

Oil consumption is the dead give away. The hths of T6 is 4.0, TDT 3.9 and yet T6 is the break in oil and has less than half the oil use per 1000 miles. Did he all of sudden switch to Biofuel or something. Now Delo goes to 0 per 1000 miles, not only that it is 0 for 5000 miles!
How can delo be louder than T6. Most diesel knock(noise) is generated by combustion and not the cam with hydraulic lifters, so was Curse fooling around with his timing. The only other thing would be the amount flow of oil and the thickness of the flow of oil in the cylinder head that might have a sound deadening affect. But the differences in these CJ4 oils is only in the additive package, the delo having lots of boron and moly and the others having much less. Delo has 550 parts of boron, how does that make it loud.
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1157741

Edit: I suggest that his oil sump is filling with biodiesel or fuel diluting and that is why he has zero oil consumption and his viscosity is water thin and that could be a more likely reason for the load noise.
Unfortunately I disagree with everything you posted...:confused:

He added his anecdotal impressions, as we all have done. Myself and others have seen increased oil consumption with TDT over multiple intervals, others have increased usage with RTS/T6. No way to pinpoint why some consume more of one or the other. The cold start difference absolutely happens, the VI corroborates it too. I bet TDT barely makes it into the 5w range, and with its unusually low VI for a 5w40, it makes sense.

Different oils CAN sound different, even of the same specs. These are not the same base stocks. This happens all the time, even with petrol engines with different oils.

FWIW TDT has an HTHS of 3.8 cP now. T6 is supposedly 4.0 cP, but it's not on the spec sheet. Delo's HTHS is also unknown.
 

James & Son

Veteran Member
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Location
Maryhill, Ontario, Canada
TDI
2006 Jetta
Bob there is a difference here. If I run 3 oils back to back( this is the assumption) and come up with T6 uses less oil during break in than TDT by double or triple the amount post breakin and then say I am now using 0 oil in 5000 miles with delo, would you not want a little more information as to what would cause such a difference in usage. You can not turn a blind eye to this strange oil usage and crop it up to hundreds of people come up with different answers. This is one person and one engine and 3 oils.
Actually fuel dilution could explain it.
 

Cursed_9d8

Member
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Apr 22, 2013
Location
Central Oregon
TDI
1998 Jetta TDI
James, for what it's worth... I do not run biodiesel. I fuel up at Chevron the majority of the time and use Standadyne diesel treatment every other tank. I have made no alterations to my engine in any way. According to my records the engine has about 125,xxx miles on it and the oil has never been overly contaminated. Just sharing my summarized observations from the driver's seat using these products. The technical data I gathered during these many thousand miles is more than I care to type in a forum.

Bob, The CJ-4 link in your signature has a lot of great info.
 

Cursed_9d8

Member
Joined
Apr 22, 2013
Location
Central Oregon
TDI
1998 Jetta TDI
The results I experienced are probably unique to my engine in my climate. The moral of the story is find a product that works best for your application all around and stick with it. Switching between them based on the season can be more harmful than beneficial, as Henrick stated.
 

James & Son

Veteran Member
Joined
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Location
Maryhill, Ontario, Canada
TDI
2006 Jetta
Cursed, Don't be afraid to get technical or add more observations or conditions that would clarify your observations. You ran the oil x miles partly winter partly summer and it buned x amount. Did the upper end diesel clatter go away when you changed out the Delo or maybe you are sticking with the delo. I think we all assume Oregon is cold in the winter.

I like to add some color to my posts once and awhile maybe to find some answers. The last thing I want is to scare you off because I like technical issues. Bob and Tooslick are our local oil gurus.

Edit: OK I reread your post and see you are sticking with T6. I sure would like to know why the delo burns no oil. I will see if I can find a UOA and see if there is any oil shear, must be extremely stable.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2653632&page=2
 
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James & Son

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Location
Maryhill, Ontario, Canada
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2006 Jetta
No prob :)

Whose Stage 2 cam is it? They may have specific recommendations.

You might also find a local Schaeffer Oil dealer and get some S9000 5w40, it's very reasonably priced.

http://www.schaefferoil.com/supreme-9000-engine-oil.html

http://www.schaefferoil.com/cmss_files/attachmentlibrary/9000-Logo.pdf
I picked up a case of 12 qts of schaeffers, a years worth for me. The main reason is A5INKY, after 100,000 miles on his lifters(50,000 with TDT and 2 oz. of zddp and then 50,000 schaeffers 9000 5w-40 with no additive). The followers had a yellow tinge.

I have had my cam out 6 or 7 times. I have looked at TDT and T6 and Petro Canada 0w-40 and 5w-40. I noticed TDT and T6 show a distinct shiniest on the cam lobes caused by the Boron in the oil or maybe the molydtc.

The petro canada has no boron and moly and has a satin finish( I have added extra Zddp and still get the same satin finish on lobes). These oils may have an affect on the follower but it is not pronouned like the lobe.

But A5INKY had the yellow tinge and because Molydtc is clear and so is boron and zddp satin clear then it has to be the Antimony in the Scheaffers. The lifters were not scuffing or picking up so it seems to work.

TDT and T6 did not stop circular scoring. PetroCanada has no magnesium in it or extra wear additives( only zddp) and is designed cold weather. It is a perfect candidate for formulating your own oil.

It was only because I found out that there is a Schaeffers warehouse reasonably close and A5INKY thread ( waited to long to change my timing belt) that I am going to give it a try.

Edit: you might find this interesting
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=729162#Post729162
 
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sirpuddingfoot

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Seattle, WA
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05 Passat, 05 Jetta
Your oil does not get to high temps unless you are on the track and have lots of mods. Otherwise, oil temp is regulated (oil/water heat exchanger).
For what it's worth, I've run both TDT and T6 for a 2-3k OCI in my 30 year old '83 Honda CB1000c (a 16v DOHC aircooled 4-cylinder motorcycle that revs to 10k) just because they were in the garage and I didn't have to go find some Rotella T 15w40. I routinely use T6 as a top up oil.

The only "issue" was that the oil pressure light blinked off faster than it does with the 15w40 on cold starts.
 

Bob_Fout

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Indiana
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2003 Jetta - Alaska Green (sold) / 2015 GTI 2.0T
For what it's worth, I've run both TDT and T6 for a 2-3k OCI in my 30 year old '83 Honda CB1000c (a 16v DOHC aircooled 4-cylinder motorcycle that revs to 10k) just because they were in the garage and I didn't have to go find some Rotella T 15w40. I routinely use T6 as a top up oil.

The only "issue" was that the oil pressure light blinked off faster than it does with the 15w40 on cold starts.
T6 is very popular with motorcycles :)
 

sirpuddingfoot

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Seattle, WA
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T6 doesn't make sense for me because the oil gets polluted so fast on this old bike making a short OCI a requirement.

T6 5w40 and T 15w40 are both Jaso-MA rated, making them very reasonably priced motorcycle oils!
 
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