Delo vs. Delvac?

Messages
52
Location
Poquoson, VA.
At Walmart I was looking at the Delo diesel oil and the Delvac. It says its approved for gas engines also. What are the main differences between these oils and regular gas engine oils? Is it the detergent package and less breakdown of viscosity? Also, I understand that diesel oils have sulphur or some other cleaners that can harm catalytic converters. Does this mean it would be fine to use in a pre-cat car? I keep reading on here that the diesel oils are very high quality, dont break down in viscosity as quick, and have a lot more cleaning agents in them. My 406 small block is pretty fresh from a rebuild, but for future reference I would like to know if it truly is OK to use diesel oil in a gas car, cat equipped or not.
 
Messages
2,768
Location
Tn
Wal-Mart here has Delo 400 and Delvac 1300. Both are 15W-40 and both are also SL rated if you look at the container. The SL makes them appropriate for gasoline engines if the viscosity is acceptable for your engine.
 

RobWest

Thread starter
Messages
52
Location
Poquoson, VA.
I used to be a 10W40 man, but over the years and after rebuilding engines for myself and others, I stick with 5W-30 year around. I think I only saw the Delo and Delvac in the 15W-40 you stated. The ONLY real thing that would scare me away from it is I have read on this site that it contains additives that can harm catalytic converters. Since diesels dont have cats, it doesnt affect them. My Camaro has a converter and I dont want to ruin it.
 
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2,768
Location
Tn
GM especially has complained that ZDDP is harmful to their cats. Not everyone agrees, but if the oil meets SL then the ZDDP levels are reduced to the agreed upon acceptable level. I would question a 15W-40 being an appropriate viscosity though unless your owner's manual calls for a 40 wt.
 
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9,448
Location
USA
THe chevy small blocks and big blocks really do not have any design flaws that would limit the use of thick oils. THe Chevy Power build up manual from GM race shop recomends 20W50 in the small blocks even with stock hydralic lifters. THis same book says that high peerformance oil pumps are not needed. It explains how to shim the bypass valve and change or modify the stock spring for 90-100 psi bypass.
 
Messages
2,513
Location
Richmond, VA
The company I work for got a new Dodge pickup several years ago (3.9 V-6) and used 15W-40 Drydene oil in it from new. Traded it after about 5-6 years with over 150,000 miles on it and never used oil or had any problems from using diesel oil. Personally, I wouldn't use it in the winter, but in the summer I can assure you that it's OK. [Cheers!]
 
Messages
12,385
Location
Northern CA
quote:
Originally posted by haley10: GM especially has complained that ZDDP is harmful to their cats. Not everyone agrees, but if the oil meets SL then the ZDDP levels are reduced to the agreed upon acceptable level.
ZDDP levels definitely were not limited for 15W-40 oils by SPI SJ and I don't beleive they are limited for 15W-40 oils by SL. Do you have any solid information to the contrary?
 
Messages
1,533
Location
Ephraim
I would not worry about the cat. Both oils are made for diesel and designed for them too, but can be run in gasoline as per their gas designations... IMO I would day Delvac is above quality than delo. They are both quality. Delo is an industry leader and a dang good product. Delvac may give better drains. Both are decent OTC oils at GOOD prices. Also IMO, they are not as MPG savy as some of their boutique counterparts, but something found all over, I wouldn't hesitate either one.
 
Messages
11,284
Location
Spring HIll
I asked this same question some time ago. Delo and Delvac have about 1100-1200 ppm of Phosphorus. As a comparison, other dinos have levels in the 800-900 range. I just can't see this making any difference in the longevity of a cat converter. the 1000ppm is a political boundary, not a practical one.
 

RobWest

Thread starter
Messages
52
Location
Poquoson, VA.
Yeah you guys are right. Brain fart! It did say for gas engines also, so I guess its cat safe. And 15W40 seems to be the popular weight. I only use 5W-30, maybe 10W-30 in the summer sometimes. I have read on here that 40 weights break down quicker, but maybe the Delo and Delvac oils are more resistant to breakdown. I have rebuilt the engines in all my cars and the oil control rings specify 30 weight oils, so that is what I use.
 
Messages
11,284
Location
Spring HIll
quote:
Originally posted by RobWest: I have read on here that 40 weights break down quicker, but maybe the Delo and Delvac oils are more resistant to breakdown.
Indeed the 15w-40's are more resistant to breakdown. The 10w-40's of the dino variety will breakdown sooner than not. The 15w-40's hold their own quite well for 5K-8K drains. Peruse through the UOA forum, this type of oil holds up real well for longer drains.
 
Messages
12,385
Location
Northern CA
quote:
Originally posted by ToyotaNSaturn: Indeed the 15w-40's are more resistant to breakdown. The 10w-40's of the dino variety will breakdown sooner than not. The 15w-40's hold their own quite well for 5K-8K drains. Peruse through the UOA forum, this type of oil holds up real well for longer drains.
The high temp high shear requirement (HTHS) for 10W-40 is only as high as the requirement for straight 30 weight oil. The HTHS requirement for 15W-40 is the same as a straight 50 weight. It's covered by SAE J300. Also, you are less likely to get reduced anti-wear additive levels in a 15W-40 that meets modern diesel oil specs as well as car specs. That makes the choice a no brainer for me when I use an xxW-40 dino oil. Dick
 

RobWest

Thread starter
Messages
52
Location
Poquoson, VA.
So I assume there is no 30 weight types of diesel oil? I am a big fan of 30 weight oils. My oil pressure is already plenty high and I dont really want to go to a 40 weight oil.
 
Messages
9,448
Location
USA
Robwest surely you can find a good 30Wt. THe shelfs at any retail store are full of 30Wt. oils! If you like Delo but want a 30Wt. get Chevron Supreme or Havoline. They use the same base stock and simalar add packages to Delo. It is diffacult to find HDDO in 30Wt. They it but almost no one uses them outside of a narrow market. Who is going to put 30Wt. in a large diesel.
 

RobWest

Thread starter
Messages
52
Location
Poquoson, VA.
My Walmart only stocks 15W-40 Delo and Delvac oils. Walmart is the only place I buy oil. The auto parts stores are too high and most dont carry much if any diesel oils.
 
Messages
2,602
Location
The Tropics of Antartica
Rob , You might could find the Mystik brand 5w-30 or 10w-30 in your area since your looking for an above average oil at low cost . This oil is a dedicated PCMO with the same type detergent/dispersents used in the HDEO along with the premium viscosity index improvers for added shear stability , something a GF-3 oil longs for [Smile] . I've been using/testing this oil for over 6 months now and think it quite honestly might be one of the best low cost over the counter PCMO dino's available at this time . But don't take this as just a SWAG just yet, it will have to prove itself through analysis which is in the works . It's 1.19 per quart usually .
 

Ler

Messages
58
Location
Sacramento, CA
Rob, regarding straight 30wt. Delo- only place I've seen it is at a marine supply store. You might give that a shot if there's one near where you are.
 
Messages
1,533
Location
Ephraim
quote:
Originally posted by Ler: Rob, regarding straight 30wt. Delo- only place I've seen it is at a marine supply store. You might give that a shot if there's one near where you are.
Here in Houston, Car Quest has it.. sometimes you have to ask. 10-30 and 30. You might try also parts houses for TRUCKS (big rigs) seen them there too. May try a mechanic shop for diesel trucks, I'd guess they's have it. Also, I know, not about Delo or Delvac, but I do know there are also any good FORK-LIFT place like CROWN or ANY other forklift place, usually has an AMPLE supply of all kinds of HDD 30w oil.
 
Messages
203
Location
NY
Yes ZDDP levels along with sulfated ash are at higher levels in diesel oil. And ZDDP levels can be harmful to cats and the ash can will leave higher residue behind (in the engine) after burning. BUT you have to take the NOACK results in to account. The higher the score the less oil that burns the less ZDDP levels going through the cat and less residue left behind. So even though they have high ZDDP levels it doesn't mean that the cat will see those levels. Just choose an oil with a high NOACK score. At least this is my view on the topic.
 
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