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15W-40 oil and 4.1/4.5/4.9 engines


adallak

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"The Rotella/Delvac/Delo diesels oils are "better" because of the higher concentration of the ANTI-WEAR additive ZDP.

Normal "gasoline engine" oil on the shelf (with the ILSAC star burst label on it saying "for gasoline engines") has lower levels of the anti-wear additive and it also has quite a bit of friction reducer additives...i..e...fuel economy improving additives.

The friction modifiers don't really hurt anything but the lack of high levels of ZDP is not good for older engines like the 4.9 with distributor drive gears which are heavily loaded. The distributor drive gear in the 4.9 engine is what needs the extra anti-wear ZDP to live.

The thicker viscosity isn't really required or necessarily "better" but it won't hurt the 4.1/4.5/4.9 engine at all. You might loose a little bit of cranking speed due to the thicker oil in the winter if you live way up north where it gets to -20 and below...otherwise, it won't hurt a thing.

Generically speaking, as an engine ages and miles pile up and some wear occurs bearing clearnaces open up slightly and the slightly thicker oil helps compensate for that, especially on the 4.9 which can often have the main bearing thump from the front main bearing with high miles.

The added ZDP is better for all engines, not just the 4.9 or pushrod engines. You have to look at the specific engine design to see if it really needs the added wear protection. The bad thing about ZDP (which contains zinc and phosphorus) is that it does poison the catalytic converter over time. Phosphorus in particular can reduce the efficiency of the cat so modern oils tend to have less and less ZDP in them to reduce the effect on the cat. As a result, modern engines are designed to run with lower and lower levels of wear protection...i.e..roller rockers, roller lifters, gerotor oil pumps, crank driven oil pumps, etc. The amount of ZDP in the oil is deliberaterly reduced and controlled in the ILSAC starburst "gasoline engine" oils to reduce the catalyst contamination. On an individual basis on one car the ZDP doesn't really affect the cat that much even over 100K but on the whole vehicle fleet (millions of cars) it does have a little effect on emissions so the reduction in ZDP is more for the common good than anything. On older engines, designed to run with oil with more anti-wear protection the new oils are not the best protection. The Rotella/Delo/Delvac is NOT rated by ILSAC for "gasoline engines" so it has much more ZDP in it since it is purposefully blended for "diesel engines" but you can use it in your gas engine with no problem.

The distributor gear drives the distributor AND the oil pump. The distributor doesn't require much force but the oil pump requires a lot of load which is what can wear the distributor gear out over time without adequate wear protection. Most cam-in-block...i.e pushrod...engines are like that, they drive the distributor and the oil pump off the cam shaft distributor gear. You are also on the right track with the gear design. A right angle drive gear is heavily loaded because there is a lot of sliding contact on the gear teeth so as the load goes up from the oil pump the distributor gear loading is increased dramatically. The distributor gear relies on the anti-wear additives in the oil to live. Same with the sliding bearing rocker arms in the 4.1/4.5/4.9. More modern pushrod engines have the oil pump on the crankshaft itself, a gerotor oil pump gear instead of spur gears, roller lifters and roller rocker arms.....all to reduce friction and reduce the engines dependency on ZDP depleted oil. This is also good in that it allows modern engines to go much further on oil changes since the oil is not depleted nearly as much and the engine is fine with the depleted oil that didn't have much ZDP to begin with. If you want more insurance against wear, though, feel free to use the Rotella/Delo/Delvac oils.

The diesel Rotella/Delvac/Delo oils are available in weights other than 15W40 (such as 10W30) but they can be hard to find as most of the class 8 diesels that the oil is specifically blended for are set up to use 15W40. Modern 15W40 oils do not have the poor viscosity improvers of past generation oils so they are fine to use. Plus, modern 15W40 oils that meet the diesel specs and the API SM performance specs have a lot of synthetic content and synthetic viscosity improvers so they are not a concern compared to the 10W40 and 15W40 oils of 20 years ago which were not desireable.

There are many factors involving the weight of the oil used in an engine including the operating temperature of the engine/oil, how the engine is clearanced when it is designed/built, what features are in the engine such as roller followers, etc.

Generally speaking I would never recommend any heavier oil than 40 weight in a passenger car engine. There are many caveats and nits to pick with that but there is really no reason to increase the oil viscosity beyond what the manufacturer recommends.

Increasing the viscosity of the oil does not necessarily lead to less wear. It can lead to more wear when the engine is cold if the oil cannot flow well. It can overload the distributor gear as mentioned if the heavy oil cannot be pumped when the engine is cold and is revved up too high. Too thick an oil can cause oil filters to blow off when the engine is cold and revved up due to excessive oil pressure.

On the other hand, air cooled motorcycle engines that are run hard will often use 50 weight oil or heavier because of the clearances in the engine opening up due to the high heat and the oil thinning excessively due to the high oil temps often seen with air cooled engines.

Understand that multivis oils such as 10W40 are basically 10 weight oil base stock with a viscosity improver package added to "thicken" the oil as it heats up so that it is the equivalent of hot 40 weight when hot. The viscosity improvers are long chain polymers that coil up when cold and stretch out when hot thus improving the viscosity. The bad thing is that the viscosity improvers, if not of very high quality, can break down in high heat areas and cause severe deposit build up that sticks rings in the piston ring grooves. This was a huge problem with multivis oils back in the late 70's and early/mid 80's with the SE and SF oils of that era. Oils with large viscosity spreads (such as 10W40) require large percentages of viscosity improvers which made them particularily bad for deposits back in the old days. That is why 10W40 oils were not recommended in many applications, why diesels never recommended multi-vis oils at all until recently and why 10W40 oils are really not recommended nor particularily desireable even today.

The viscosity improvers of today in the SL and SM rated oils are pretty much all synthetic and do not cause deposit formation problems anymore. Even so, mulit vis oils that meet the highest diesel performance specs are of the 15W40 variety which require less VI percentage than a 10W40 would....i.e..it takes less VI to make a base 15 weight oil the equivalent of a hot 40 weight than a base 10 weight oil.

In any case, it doesn't hurt much to increase the oil viscosity a little in most cases but the best approach is to use the recommended oil viscosity for the engine and not try to second guess the engineers that developed the engine. Most current production engines are recommended for 10W30 and lately 5W30 for improved fuel economy. The engines are designed for that and substituting thicker oil will not help durability at all and it would definitely hurt the fuel economy.

In the winter, cold cranking speed is governed by the oil viscosity. If you were to use 50 weight oil in very cold weather the engine would never start due to the fact that it would likely barely crank over. In cold weather 5W30 and 0W30 oils are common for cranking purposes."

The saddest thing in life is wasted talent

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Thanks Adallak.

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Thanks Adallak.

definitely worth considering...

jackg 90seville

101k

Did you see the info on the Oil Life Monitor?

http://caddyinfo.ipbhost.com/index.php?showtopic=9393

Mike

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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Jack that is a link to a thread from yesterday called Oil Life Monitor, the guru explains it fully... If you have not seen it, its a good guru read...

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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i just called autozone: they don't carry diesel motor oils in 10w-30 weight (only 15w-30 or 15w-40...can't remember the exact weight he stated). if i could find 10-30 in a diesel motor oil i think i would use it for my next oil change. the lack of zdp for and the friction modifiers for the current crop of engines doesn't sound good for us old timers.

jackg 90seville

101k

oh yeah, i read that thread from yesterday about the oli. just had the oil changed last week...there was still 20percent left but i wanted to have it done since it was in the shop for the coolant system service.

jackg 90seville

101k

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i just called autozone: they don't carry diesel motor oils in 10w-30 weight (only 15w-30 or 15w-40...can't remember the exact weight he stated). if i could find 10-30 in a diesel motor oil i think i would use it for my next oil change. the lack of zdp for and the friction modifiers for the current crop of engines doesn't sound good for us old timers.

jackg 90seville

101k

oh yeah, i read that thread from yesterday about the oli. just had the oil changed last week...there was still 20percent left but i wanted to have it done since it was in the shop for the coolant system service.

jackg 90seville

101k

Jack,

It is hard to believe that IdiotZone didn't have Rotella oil. I buy it at Menards of all places - they even have the Rotella in the 10W30 grade.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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looking for the specific brands that were mentioned was my first thought. i will pursue that later. i did go to the valvoline website and did some research on their maxlife oils and their conventional oil. in their product info, both the conventional and the maxlife oils list the same amount of zinc and phosphorous. i'm assuming that the zinc phorphorous is akin to zdp or zddp. this will require more homework.

jackg 90seville

101k

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looking for the specific brands that were mentioned was my first thought. i will pursue that later. i did go to the valvoline website and did some research on their maxlife oils and their conventional oil. in their product info, both the conventional and the maxlife oils list the same amount of zinc and phosphorous. i'm assuming that the zinc phorphorous is akin to zdp or zddp. this will require more homework.

jackg 90seville

101k

Look for Shell Rotella, Mobil Delvac, or Chevron Delo oils - they are the 15W40 Diesel oils. Rotella has a 15W30 grade of Rotella now too.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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I've been using Exxon/Esso diesel oil (XD3) for over 40 years in all my vehicles. Lawn mower included.

It's been great.

Available in 10W-30 and 15W-40.

http://www.exxon.com/USA-English/Lubes/PDS...W-30_15W-40.asp

Question.

In almost every article or discussion about diesel oil, Exxon/Esso is rarely mentioned.

Is there something I should know ?

Is this not a popular brand ?

Just curious.

Thanks

Barry

2008 STS V8
2016 Colorado Z71
1970 Corvette LT-1 Coupe

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I've been using Exxon/Esso diesel oil (XD3) for over 40 years in all my vehicles. Lawn mower included.

It's been great.

Available in 10W-30 and 15W-40.

http://www.exxon.com/USA-English/Lubes/PDS...W-30_15W-40.asp

Question.

In almost every article or discussion about diesel oil, Exxon/Esso is rarely mentioned.

Is there something I should know ?

Is this not a popular brand ?

Just curious.

Thanks

Barry

I don't think there's anything bad about Esso/Exxon oil. In the US, it seems like Rotella, Delvac, Delo are what is readily available.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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I have seen Rotella in Costco guys

Pre-1995 - DTC codes OBD1  >>

1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm

How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/

Cadillac History & Specifications Year by Year  http://www.motorera.com/cadillac/index.htm

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I have seen Rotella in Costco guys

Farm and Fleet, too...

Scott

1996 El Dorado

2006 STS

2000 Corvette

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I have seen Rotella in Costco guys

Farm and Fleet, too...

WOW! You come all the way out here from Chicago to go to Farm & Fleet? Now that is a shopping trip.

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About diesels from the same source:

"Diesel engines don't have catalytic converters to worry about contaminating so the ZDP is of no concern to the diesel manufacturers.

When we say 'diesels" think class 8 18 wheelers, big Cat, Cummins, etc. and off road construction equipment....not just on-road passenger car and light truck diesels.

Diesel manufacturers have their own sets of performance requirements. Read the oil cans. See the API diesel specs such as CC and CD and many others. For diesels these specs supercede any gasoline performance specs such as SL and SM you see on oil cans of oil for "gasoline engines".

Diesels put a lot of soot in the oil so the oil is more heavily contaminated by soot and other combustion byproducts and blowby. Due to the nature of diesel combustion the engines produce more soot (the black smoke you see) and the high compression of diesels (22:1 or more) pushes some of the soot past the ring pack and into the oil. Soot is carbon which is very hard and very abrasive.....sooo...diesels oils have much more ZDP to prevent wear so as to be able to pass the diesel specific wear performance requirements for the API diesel specs.

Used to be the oils for diesels had to be very specific and wouldn't be desireable in gas engines. With the high performance oils of today the diesel oils are very good and very good for gas engines, too.

Manufacturers test for EPA fuel ecoomy performance with friction modified oils to improve the economy. The EPA wants you to be using those types of oils. That is why there is the "for gasoline engines" ILSAC starburst symbol on most common auto oils. They also spec reduced ZDP in those oils to reduce the possibility of contaminating the cat. The best oils, though, for wear and ZDP concentration are the current diesel oils and it doesn't hurt a thing to use them in gasoline engines."

The saddest thing in life is wasted talent

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I always recommend that anyone running an engine from the mid-80's and earlier use one of the non-GF-3 or non-GF-4 rated oils on the market. Those Heavy Duty oils are NOT friction modified and have higher levels of antiwear additives. Oils such as DelVac, Delo and Rotella , which are typically available in gallon jugs at Walmart and are viewed as "18 wheeler diesel oils" are EXCELLENT for earllier model engines. Modern engines of the 90's and 2000 and later are designed to run on the GF-3/4 friction modified oils with lower levels of antiwear treatment. The Delo/Delvac/Rotella oils meet the SL performance requirements but cannot be GF-3/4 rated due to the lack of friction modifiers for fuel economy. This is a good thing in an engine that is more sensitive to lubrication requirements.

Whatever it's worth, I found the above quote on CadillacOwners.com.

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About diesels from the same source:

"Diesel engines don't have catalytic converters to worry about contaminating so the ZDP is of no concern to the diesel manufacturers.

When we say 'diesels" think class 8 18 wheelers, big Cat, Cummins, etc. and off road construction equipment....not just on-road passenger car and light truck diesels.

Diesel manufacturers have their own sets of performance requirements. Read the oil cans. See the API diesel specs such as CC and CD and many others. For diesels these specs supercede any gasoline performance specs such as SL and SM you see on oil cans of oil for "gasoline engines".

Diesels put a lot of soot in the oil so the oil is more heavily contaminated by soot and other combustion byproducts and blowby. Due to the nature of diesel combustion the engines produce more soot (the black smoke you see) and the high compression of diesels (22:1 or more) pushes some of the soot past the ring pack and into the oil. Soot is carbon which is very hard and very abrasive.....sooo...diesels oils have much more ZDP to prevent wear so as to be able to pass the diesel specific wear performance requirements for the API diesel specs.

Used to be the oils for diesels had to be very specific and wouldn't be desireable in gas engines. With the high performance oils of today the diesel oils are very good and very good for gas engines, too.

Manufacturers test for EPA fuel ecoomy performance with friction modified oils to improve the economy. The EPA wants you to be using those types of oils. That is why there is the "for gasoline engines" ILSAC starburst symbol on most common auto oils. They also spec reduced ZDP in those oils to reduce the possibility of contaminating the cat. The best oils, though, for wear and ZDP concentration are the current diesel oils and it doesn't hurt a thing to use them in gasoline engines."

the first part regarding the cat converters is what concerns me: the added zdp in the diesel oils might be a problem with causing a failure and not being able to pass the emmissions test. it does state on the exxon and shell web sites that their diesel oils are safe for use in passenger vehicles.

jackg 90seville 101k

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very interesting....i sent an email to shell oil regarding my concern over the use of their rotella oils in a gasoline powered engine with a cat converter. they acknowledged the fact that there would be an increased degradation or "posoining" (his word) of the cat and in time the added zddp would cause an accelerated failure of the cat.

this confirmed my suspicions after reading the dear departed comments re the use of diesel oils. in my case, i must go though an emmissions inspection, on the tread mill and run at speed, every other year.

failing the test isn't something high on my list.

jackg

90seville

101k

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very interesting....i sent an email to shell oil regarding my concern over the use of their rotella oils in a gasoline powered engine with a cat converter. they acknowledged the fact that there would be an increased degradation or "posoining" (his word) of the cat and in time the added zddp would cause an accelerated failure of the cat.

this confirmed my suspicions after reading the dear departed comments re the use of diesel oils. in my case, i must go though an emmissions inspection, on the tread mill and run at speed, every other year.

failing the test isn't something high on my list.

jackg

90seville

101k

Jack,

I wouldn't worry about the poisioning of the catcon - the amount of ZDP in the Rotella oil is comparable to the amount that was in 10W30 in 1989-1990 or so when your car was built. The amount of ZDP in 10W30 has been reduced over the years due to distributorless ignitions, roller cam followers, etc.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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very interesting....i sent an email to shell oil regarding my concern over the use of their rotella oils in a gasoline powered engine with a cat converter. they acknowledged the fact that there would be an increased degradation or "posoining" (his word) of the cat and in time the added zddp would cause an accelerated failure of the cat.

this confirmed my suspicions after reading the dear departed comments re the use of diesel oils. in my case, i must go though an emmissions inspection, on the tread mill and run at speed, every other year.

failing the test isn't something high on my list.

jackg

90seville

101k

Jack,

I wouldn't worry about the poisioning of the catcon - the amount of ZDP in the Rotella oil is comparable to the amount that was in 10W30 in 1989-1990 or so when your car was built. The amount of ZDP in 10W30 has been reduced over the years due to distributorless ignitions, roller cam followers, etc.

\

kevin:

that's a valid point if it's in fact the case. i will go back to my contact at shell and ask him. thanks for the tip.

jackg 90seville 101k

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