diesel oil vs. regular motor oil

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I still have several liters of Esso XD-3 0w30 which was all the craze on this board about 10 years ago.
It's a dual rated (SL) 30 weight which is on the thick side:
https://bobistheoilguy.com/forums/ubbthreads.php/topics/478451/Esso_XD3_0w30#Post478451

I may run it in my daughters 2008 Elantra (which allows SJ,SL and SM...and of course SN and also allows 30 weight) with a FU filter when she heads off to work 800 miles away this summer. I'm thinking that 10-12K would be doable if I don't see the car for a while.

Thoughts on my idea?
 
Originally Posted By: FordCapriDriver
Say you are comparing a 15W-40 HDEO or Mixed fleet diesel oil, with a 10W-40 conventional passenger car oil.
The 15W-40 "diesel" oil wins in a lot of things:
It will have stouter base stocks.
HTHS Viscosity is pretty much guaranteed to be higher ( viscosity at 300F )
They pretty much always have hig levels of ZDDP which is an additive used to prevent camshaft wear on old flat tappet engines.
It will probably have a Higher Total Base Number, which is the oil's ability to fight off acids.
It will probably have more detergents and dispersants which will keep the engine clean.
They require less Viscosity index improvers, which means the oil will maintain its viscosity for longer, and also VIIs create deposits when destroyed and form deposits inside the engine.
It will probably even be cheaper than a 10W-40 Passenger car oil!
Keep in mind oil companies have in mind that a 15W-40 HDEO will be used in equipment that is worth sometimes hundreds of thousands of dollars, they cannot afford to have an engine failure caused by one of their oils, so they put a lot of effort into designing these oils.


Been running Delo, Rotella and Delvac in gas cars and trucks for something like 30 years. It's usually rated for both and is a "fleet oil". If UPS and FedEx can use it in gas and diesel fleets, so can I. Their lawyers would make life miserable for any refiner that made a bad oil and lead to motor failures ...
 
I use it in my ATV and will start using it in my older flat tappet engines for the ZDDP. Something PCMO's don't have enough of nowadays for older engines.
 
Originally Posted By: Reddy45
I think any newer CK-4/SN (dual rated for diesel and gas) oil won't have as much of an advantage over a good quality gasoline engine oil.

When the ZDDP levels were high, we were told it was the wrong kind of ZDDP for "classic cars." Now, there's too little of the wrong kind of ZDDP.

Of course, ZDDP aside, an HDEO can have elevated HTHS, which isn't easy to find in the ILSAC land of Walmart, or general retail oil shelves.
 
Of course, what's always forgotten is that every newer oil category, diesel- or gasoline-engine, has same or better wear protection than the previous oil category. So, it's not the amount of ZDDP that tells you how much wear protection you get. It's the oil category (API SP, SN, CK-4, CJ-4, etc.).
 
Originally Posted By: Gokhan
Of course, what's always forgotten is that every newer oil category, diesel- or gasoline-engine, has same or better wear protection than the previous oil category. So, it's not the amount of ZDDP that tells you how much wear protection you get. It's the oil category (API SP, SN, CK-4, CJ-4, etc.).

You are ingoring the fact that there have been a lot of flat tappet camshaft/ lifter failures in recent years because of low zddp API SM and SN oils, an oil that is high in zddp and that also had modern specifications is where it's at, that is why i'm switching to Valvoline VR1 20W-50 soon, API SM ACEA A3/B4 and has 12-1300ppm of zddp + fm's etc.
 
Last edited:
Originally Posted By: FordCapriDriver
Originally Posted By: Gokhan
Of course, what's always forgotten is that every newer oil category, diesel- or gasoline-engine, has same or better wear protection than the previous oil category. So, it's not the amount of ZDDP that tells you how much wear protection you get. It's the oil category (API SP, SN, CK-4, CJ-4, etc.).

You are ingoring the fact that there have been a lot of flat tappet camshaft/ lifter failures in recent years because of low zddp API SM and SN oils, an oil that is high in zddp and that also had modern specifications is where it's at, that is why i'm switching to Valvoline VR1 20W-50 soon, API SM ACEA A3/B4 and has 12-1300ppm of zddp + fm's etc.

There were a lot of flat-tappet failures even in the old days because that's an inferior lifter design. So, it's not really the oil's fault. Do you think the old oils were better? No. However, you can give the new racing oils a try.
 
do anyone know what the levels of ZDDP are in the delvac 15-40 diesel oil compared to Mobil 20-50 ? where can i look to see the levels ?
 
THANKS ! looks like Mobil 1 blows everyine else out of the water. the cost is thething with it. looks like a good diesil oil would work just fine for an older low revving flat tappet engine.
 
Originally Posted By: Gokhan
Originally Posted By: FordCapriDriver
Originally Posted By: Gokhan
Of course, what's always forgotten is that every newer oil category, diesel- or gasoline-engine, has same or better wear protection than the previous oil category. So, it's not the amount of ZDDP that tells you how much wear protection you get. It's the oil category (API SP, SN, CK-4, CJ-4, etc.).

You are ingoring the fact that there have been a lot of flat tappet camshaft/ lifter failures in recent years because of low zddp API SM and SN oils, an oil that is high in zddp and that also had modern specifications is where it's at, that is why i'm switching to Valvoline VR1 20W-50 soon, API SM ACEA A3/B4 and has 12-1300ppm of zddp + fm's etc.

There were a lot of flat-tappet failures even in the old days because that's an inferior lifter design. So, it's not really the oil's fault. Do you think the old oils were better? No. However, you can give the new racing oils a try.


Non-roller lifters were an "inferior" design?
Try telling that to the millions of owners who drove these engines to hundreds of thousands of miles each.
I've had flat lifter engines and never had any problems with them in either rocker or cam wear.
 
Originally Posted By: fdcg27
Non-roller lifters were an "inferior" design?

It's not the rolling/sliding part that's the problem. In fact, early designs had roller tappets, which actually caused even more wear and then they decided to use flat tappets.

https://en.wikipedia.org/wiki/Tappet

It's the design. The angles and edges in the flat-tappet geometry are problematic. I have sliding (nonrolling) rocker arms in my engine and there is no wear issue. Of course, newer, rolling rocker arms have even less wear.

https://en.wikipedia.org/wiki/Rocker_arm
 
Originally Posted By: hardheaded
THANKS ! looks like Mobil 1 blows everyine else out of the water. the cost is thething with it. looks like a good diesil oil would work just fine for an older low revving flat tappet engine.

Which Mobil 1? Regular Mobil 1 doesn't have much ZDDP (zinc/phosphorus).

Chevron Delo® 400LE SAE 15W-40 API CJ-4/CI-4 Plus/SM has 1500 ppm zinc and 1300 phosphorus according to the PQIA test.
 
Originally Posted By: Gokhan
Originally Posted By: fdcg27
Non-roller lifters were an "inferior" design?

It's not the rolling/sliding part that's the problem. In fact, early designs had roller tappets, which actually caused even more wear and then they decided to use flat tappets.

https://en.wikipedia.org/wiki/Tappet

It's the design. The angles and edges in the flat-tappet geometry are problematic. I have sliding (nonrolling) rocker arms in my engine and there is no wear issue. Of course, newer, rolling rocker arms have even less wear.

https://en.wikipedia.org/wiki/Rocker_arm

I know that flat tappets are an inferier design with a lot more friction, but still you are ignoring the fact that modern low zddp oils are causing a lot of camshaft failures in flat tappet engines in the last few years, the zddp is in there for a reason and in the 70s it was discovered that in the average American V8 of the time a concentration of about 1200ppm was the sweet spoot for reducing valvetrain wear, modern API SM/SN ILSAC Oils that are limited at 800ppm don't provide the needed camshaft protection despite being better on many other things.
 
Originally Posted By: hardheaded
does anyone run diesel oil in the gas engines ?



Run Shell Rotella T-6 5W40 in a 92 Explorer 4x4 and a 05 Honda VT1100. No issues at all.
 
Regardless of what one might find on Wikipedia, non-roller rocker arms served just fine on tens of millions of engines built over a number of decades.
The engine in your old Corolla is just one example of this.
 
Again, if the OP is looking for a high-ZDDP oil, the best choice seems to be the very low-priced Chevron Delo® 400LE SAE 15W-40 API CJ-4/CI-4 Plus/SM, which has 1500 ppm zinc and 1300 phosphorus according to the PQIA test. It also has about 120 ppm moly. So, it's a ZDDP + moly monster.
 
Will diesel oil work in a 1976 MGB? I believe it is a flat tappet motor that needs hi ZDDP oil. Right now I'm running the Valvoline racing oil but that is somewhat difficult to find around here. If I can use a diesel motor oil I'll do that because it will be easier to find and probably a little cheaper.
 
Originally Posted By: Mossyoakglock
Will diesel oil work in a 1976 MGB? I believe it is a flat tappet motor that needs hi ZDDP oil. Right now I'm running the Valvoline racing oil but that is somewhat difficult to find around here. If I can use a diesel motor oil I'll do that because it will be easier to find and probably a little cheaper.

Yes, probably, the brand new SN/CK-4 mixed fleet oils have slightly less ZDDP but i have seen a VOA of the new Shell Rotella in CK-4 form and it still had a "decent" amount of ZDDP in it, old British classics like your MGB love a good old goopy Dino 20W-50 that is loaded with Zinc and FM's , but a 15W-40 HDEO works just as well.
If the seals and gaskets are good you could use Mobil 1 15W-50, this still has ZDDP in the 1200ppm range, and it is not hard to find.
Keep in mind that when using a "Diesel" oil, it needs to also have a Gasoline rating ( SL,SM,SN ) a straight up diesel oil with no Gasoline API rating would not be a good idea.
 
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