using motor oil for a diesel engine in a gasoline engine

[njot33]

I have been thinking of putting slightly heavier weight oil into my 1965 330 V8, which has a slight rod knock when it is started cold. It then goes away after a few minutes.

Currently I use nonsynthetic 10W-40. I had been thinking of switching to 15W-40 to help reduce the cold rod knock. I don't want to use 20W-50 because I think that's TOO thick.

I realize I could just mix half 10W-40 and half 20W-50 and get 15W-45, but I had seen containers of 15W-40 at the auto parts store. All of the 15W-40 containers seem to be intended for diesel engines or other heavy machinery, not cars with gas engines. I did not go ahead and buy this because I don't know if it's the right thing to use. Does anyone know if there's any harm in using motor oil meant for diesels in a gasoline engine?

Thanks.

[csstrux]

I suppose there are issues in new cars, but I own a very small trucking company, and buy sae 15w40 in bulk. I run this oil in my 89 jimmy with a 454 year round and in my wifes 02 impala with the 3800 v6 in temperate weather. I have been doing this for the last 4 years plus, with no ill effects noted. I have a friend who is a sae certified tech who warned me about running heavy oils in the newer cars in cold climates. I know you are talking about an old one on it's last legs, but I have had good luck all around, and would consider it's use in all my vehicles, as the cleaning properties are increased as well as the lubricating properties. Joe Padavanno sp? really knows his stuff and may have a differing opinion, but as I've said I have had good luck with it. Hope this helps.

[Lady72nRob71]

I do know the diesel oils are rated for much higher running temperatures.
Harley Davidson air-cooled engines require diesel rated oils due to the fact that they run at 300*F+ cylinder temps.
The cleaning agents may be different, but not too sure.
I think the viscosity is the main thing to watch.

[Jokers69]

I run Shell Rotella 15/40 in my car, not only heavier weight, but the diesel oils have a better wear additive package that the gasoline engines have been deprived of since catalytic converters and emission controls have gotten stricter.

[njot33]

This is good to know.
I was going to use Shell Rotella 15W-40 in the 65 Olds.

I thought it would not be a problem but wanted to make sure.

[rocketraider]

Look on the diesel oil bottle and you'll see a round API symbol with something like "rated for service CI-4/SM". This means it can be used either in gasoline (Spark ignition) or diesel (Compression ignition) engines. These are currently the highest ratings for motor oil and supposedly surpass anything refined to date, though it's known that these oils have less anti-wear and anti-scuff additives than CH-4/SJ oils. They're great for roller cam engines but I like a little more protection on a flat tappet engine. That's why I use diesel rated oil in all my older engines.

[88 coupe]

Originally Posted by njot33

........ I don't want to use 20W-50 because I think that's too thick. ........

Not if you are trying to "band aid" a rod knock. You'll get more mileage out of it with a thicker (40 0r 50W) oil, for cool/cold starts, when you actually need it. At normal operating temps, both 50W and 20W-50 will be the same viscosity.

Having said that: Don't expect an "oil change" to buy you a lot of time.

Norm

[njot33]

What I'm trying to do is slowly increase the viscosity until I no longer hear the knock. I THINK it is a rod knock. It sounds like the bottom end to me.

It's not that bad or that loud, but it does happen the first few seconds when the engine is started. It's worse when the weather is very cold. It goes away pretty quickly.

I don't drive this car that much. If I thooght the engine was about to die, I'd rebuild it now, but I don't think it's at that stage yet.

[88 coupe]

Originally Posted by njot33

........ It's not that bad or that loud, but it does happen the first few seconds when the engine is started. It's worse when the weather is very cold. It goes away pretty quickly ........

Good description of my 350. Got it for a good price because of it. When I change the oil it goes away for a week or two, then slowly returns.

Don't know what it is, but it hasn't changed in about 5 years/14,000 miles. When/if it gets worse, I'll deal with it.

Been using 20W-50, in all my cars, for more than a few years.

Norm

[Redog]

Will the 15w-40 oil help in the Delta?

[Jokers69]

Originally Posted by Redog

Will the 15w-40 oil help in the Delta?

Of course.. 15w40 oil is good anywhere in the country, from New England to the Mississippi Delta.. I hope I spelt that right, tried to remember the little rhyme.

[csstrux]

Originally Posted by Redog

Will the 15w-40 oil help in the Delta?

About the only drawback that you may notice is a slight drop in fuel economy as you will have a bit more drag internaly. Oterwise it is a better oil all round IIMHO.FYI I am running shell rotella 15-40 in everything I own.

[marcar1993]

Deisel oild in a gas motor is like running 10w40. The big difference is that they have more cleaners in deisel oil. Just like switching to synthetic, it can cause leaks in an older motor running on conventional all its life. I have run 10w40, 15w40 deisel, and 20w50 in my 307 and it didn't mind them all. The deisel oil cut all the sludge as I wanted it too, but now it leaks a little.

[Jokers69]

when I did my engine 2 winters ago the cam/lifter package I purchased (COMP CAMS) had a tech sheet that recommended breaking in by running the 15/40 diesel oil along with the break in lube, because of the lack of wear additives in todays conventional motor oils. I've been runnung the diesel oil since, plus every other change gets a bottle of the break in lube. My engine guy stocks the Crane brand so thats what I use.

Here is a copy/paste from their website.

Flat Tappet Break-In
All flat tappet cams will require special attention during the break-in process. Due to recent changes in motor oil formulas, a switch to a diesel or non-synthetic racing motor oil in combination with COMP Cams® #159 Camshaft Break In Lube is mandatory in order to avoid camshaft failure during break in. Cams requiring dual valve springs during normal operation will also require that the inner valve spring be removed during break in so that critical lifter rotation can be established. The appropriate COMP Cams® lifters, and correct valve springs, rocker arms, and pushrods are also absolutely essential to ensure long camshaft life. Please refer to the instructions in your cam box for complete procedures or page for our tech bulletin on the topic If ever in doubt, please call the COMP Cams® CAM HELP® line at 1-800-999-0853.

[Viper]

most diesel oil is a non detergent, other than that oil is oil..years ago they came up with multigrade oils, for the lazy man, reason so when winter came, he did not have to change his oil from 30 weight to 20 weight... viper..

[Jokers69]

the stronger clean air standards and catalytic converters caused the oil companys to back off on the antiwear good stuff like the Zinc (ZDDP).
Products like Royal Purple racing oil (off hiway use doesn't have to meet the guidelines) still have a decent package.

Here's an artical tease and link to whole thing at Hot Rod

http://www.hotrod.com/pitstop/hrdp_0...ive/index.html

Zinc Oil Additive
The benefits of oils with a higher zinc content, or using a zinc additive.


writer: Marlan Davis

Zinc Oil Additive
-February 2007-

Question: I thoroughly enjoyed the tech article "When Good Cams Go Bad" (June '06), but I have a couple of questions: If you have an older car without a catalytic converter but don't have flat tappets, is there any advantage to using the oils with higher zinc content? Also, I have a '56 Chevy with a Bill Mitchell 427 small-block. It has the aluminum block and heads (my version of a ZL1). Is there any adverse reaction between aluminum and zinc?
Ron McCranie
Denver, CO

Answer: Quaker State engineer Mark Ferner said zinc's extreme pressure qualities also aid in reducing piston ring-to-cylinder bore wear at BDC and TDC, where the rotating assembly sees an abrupt change in velocity and direction. Besides its extreme pressure protection, multifunctional zinc also functions as an antioxidant. That is, things exposed to heat and oxygen are subject to oxidation. In the case of a ferrous metal like iron, oxidation causes corrosion, which we see as rust. As applied to motor oil, Ferner said as the "heat accelerates oxygen, the oil starts to oxidize and thicken, changing into other molecular combinations. As the oil thickens, it forms deposits or varnish. In motor oil, the antioxidant additives first sacrifice themselves to prevent this oxidation from occurring, but if they get overwhelmed, the oil eventually turns into a hard, crusty sludge......"

[Bluevista]

I use the Rotella too because of the zinc content mentioned and it was highly recommended when I looked online for break-in when I was doing my engine. It is not exclusively for diesels, on the container it says for diesel and gasoline engines. The only problem I have heard of is they changed the diesel oil standards and there is less zinc in the new formulation, still better than regular oil for older engines from everything I've read.


Allan

[71rocket]

All our cars, new and old, get the same thing our tractors get.....Retella 15-w40. No problems.

[Joeypete]

I just switched to 15W40 in my Toronado. I was using Mobil1 Synthetic 10W30. I hadn't even put 3000 miles on it yet and the oil had turned black! I imagine it cleaned up some grime, but I was amazed how the color turned. Since I live in the desert I wanted to run a slightly thicker oil, those 307's get pretty hot to begin with. It drives a lot better now and is quieter, she seems to like it.

I wanted to buy the Rotella, but Checker had the Chevron Delo on sale for 9.99 a gallon...couldn't beat that. I assume they are similar?

[Wireman134]

Originally Posted by Joeypete

I just switched to 15W40 in my Toronado. I was using Mobil1 Synthetic 10W30. I hadn't even put 3000 miles on it yet and the oil had turned black! I imagine it cleaned up some grime, but I was amazed how the color turned. Since I live in the desert I wanted to run a slightly thicker oil, those 307's get pretty hot to begin with. It drives a lot better now and is quieter, she seems to like it.

I wanted to buy the Rotella, but Checker had the Chevron Delo on sale for 9.99 a gallon...couldn't beat that. I assume they are similar?

Yea, use a diesel oil CI-4 is the best rating to look for, CJ-4 oils have a reduced amount to comply with the cleaner 2007 diesel engines. They still have plenty of ZDDP (zinc and phosphorus) additive in them for flat tappet cams, roller cams don't need so much and it clogs the cats on your exhaust. Your looking for a minimum of 1000 ppm for a existing broke in cam and like 1600 ppm for a new cam break in. These high pressure additives allow a oil to last long in a diesel engine and have excellent base stocks. Stock up on the CI-4 if you can still find it. Or you have to run a high dollar "Classic Car Oil" to have the wear protection older engines need.
Check out link this is about 2 yrs old when CJ-4/SM HDDO's were changing over. Many fleet operators do not want to compromise (shorten) there drain intervals because of the lack of the proven additive (ZDDP) in their diesel oils.
http://www.dieseltruckresource.com/d...5&d=1225036035

http://www.hotrod.com/techarticles/e...ech/index.html

[Joeypete]

Awesome info, thank you. Very interesting stuff. Motor oil fascinates me, for some strange reason

I have the 307's with roller cams so I guess the Delo is ok...it says on the bottle it's CJ-4 as does Rotella from what I can tell. Should work fine I guess.

[J-(Chicago)]

Valvoline VR1 20-50, Brad Penn, or AMS if you beat the snot out of it.
I ran regular SAE 30 oil at the track for 5 passes and got a nice filter full of glitter.
Regular oil is cat piss, plain and simple. You can use it for puttering around town I suppose, but other than that it's useless to me. I wouldn't even use it on the expressway now.

[Nilsson]

Originally Posted by J-(Chicago)

Valvoline VR1 20-50, Brad Penn, or AMS if you beat the snot out of it.
I ran regular SAE 30 oil at the track for 5 passes and got a nice filter full of glitter.
Regular oil is cat piss, plain and simple. You can use it for puttering around town I suppose, but other than that it's useless to me. I wouldn't even use it on the expressway now.

x 2 on the VR1 and you can score it almost anywhere.

[D Appeldorn]

so if i gona change my oil i can better use a ci4 diesel oil instead of 10w40 semi or mineral oil?

i can perchase from comma the premium dieseloil from tradeoil oils. see commaoil.com

they also have clasic oils but don't know if it's right for my 88

so if i understand it, i should get the ci4 oil to change oil on a 350 oldsblock of say it 69'

[BosMobile]

Hey,if you do a search on ZDDP,you can read about oil differences all night.Got me confused,man.After it all the VR1,valvoline,seems to be a good choice.I've always used STP with my oil changes,dont care what you say,at 229,ooo there was barly a ring groove.Sold me.It also has ZDDP in it.Good luck with it,later on,BO

[HARDLUCK88]

this is a good topic!

[Wireman134]

Originally Posted by D Appeldorn

so if i gona change my oil i can better use a ci4 diesel oil instead of 10w40 semi or mineral oil?

i can perchase from comma the premium dieseloil from tradeoil oils. see commaoil.com

they also have clasic oils but don't know if it's right for my 88

so if i understand it, i should get the ci4 oil to change oil on a 350 oldsblock of say it 69'

Any Diesel oil (HDMO) is better than the current SM passenger car oils for flat tappet cams. Walmart Supertech 15w40 is still CI/SL rated. Or buy the $7+ Racing/Specialty oils that are marketed twords Classic engines.

[Destructor]

Does Valvoline VR 1 have detergents? I added 1.5 quarts of 20-50 on my last oil change the rest mobile 10-30 conventional. I already had the mobile oil and the store only had the 20-50 VR 1 in stock. I don't want to run all non detergent oil.

[Dan Wirth]

Originally Posted by njot33

I have been thinking of putting slightly heavier weight oil into my 1965 330 V8, which has a slight rod knock when it is started cold. It then goes away after a few minutes.

Currently I use nonsynthetic 10W-40. I had been thinking of switching to 15W-40 to help reduce the cold rod knock. I don't want to use 20W-50 because I think that's TOO thick.

I realize I could just mix half 10W-40 and half 20W-50 and get 15W-45, but I had seen containers of 15W-40 at the auto parts store. All of the 15W-40 containers seem to be intended for diesel engines or other heavy machinery, not cars with gas engines. I did not go ahead and buy this because I don't know if it's the right thing to use. Does anyone know if there's any harm in using motor oil meant for diesels in a gasoline engine?

Thanks.

I don/t know about diesel engine oil for a gas engine, but had a similar problem with my 57 Olds. My mechanic suggested Gastrol 40W (straight 40W). And I have seen a substantial improvement in the sound of my engine (lifters). Because oil runs off the engine via gravity when cold, typical for the age and technology of my car, it takes a lot longer for it to warm up. However, even after warm up I detected some faint noise. However, with the 40W, this sound went away.

[Lady72nRob71]

Originally Posted by Wireman134

Any Diesel oil (HDMO) is better than the current SM passenger car oils for flat tappet cams. Walmart Supertech 15w40 is still CI/SL rated.

The test report on this stuff looks quite good (high ZDDP) for passenger car use! A huge improvement over the "cat p*ss" SM oils that are being made for new cars.
My old ford will be getting the above oil since it uses a flat tappet cam (still original!)
Time to stock up on CI oils - CJ is not very good, yet still better than SM.

[My442]

I have used diesel oil in all my collector cars since the mid 1980's.

Ran 5 engines on the dyno with diesel oil for break in.

Never had an issue, and when you pull the valve covers, the inside of the engine is spotless.