Diesel oil for Gasoline Engines ???

[Jack_440 Savoy]

I was looking at motor oil yesterday and I was wondering about using Castrol Diesel 15-40W in a gasoline engine. I know it would be a "High Detergent" oil that might not be good for a older engine, but for a low mileage engine I'am thinking it would be a "Good Thing". I quite like the idea of a 15-40W oil. I never really felt totally comfortable with 20-50 W. So what do you all think about Castrol GTX Diesel 15-40W compared to Castrol GTX 20-50W ??? Jack

[wilks3]

Comp Cams swears buy Shell Rotella 15w40 for camshaft break-in. When my 440 gets another 1500 miles on it I'm switching over to 15w40 Royal Purple. 10w40 too thin base oil for me, 20w50 too thick for my use. Hope this helps.

[ehostler]

Here is what Hughes engines has to say -

As far as I can determine at this point, the best stuff for your crankcase is a heavy duty oil (not an energy conserving oil) either a straight weight or 10W-40 or 20W-50 racing oil or 15W-40 diesel oil if it has a CI-4 or CI-4+ rating. At this time we do not recommend any synthetic oils for use with flat tappet cams.

One of the side problems is that high detergent oils tend to be lower in antioxidents. That allows your oil to breakdown quicker.

[Jack_440 Savoy]

I wonder why they would "Not recommended" Synthetic oil, is that what they refer to as a "energy conserving oil" I thought Synthetic oil would be Good for any engine. Only draw back would be the cost, I would think.

[451Mopar]

Originally Posted by Jack_440 Savoy

I wonder why they would "Not recommended" Synthetic oil, is that what they refer to as a "energy conserving oil" I thought Synthetic oil would be Good for any engine. Only draw back would be the cost, I would think.

They claim the Synthetic is too slippery, and does not rotate the lifter on the cam?

[Crank]

i use it so far so good in my truck with 90 ,000 miles .i like it and would recomend it as good quallity oil.

[Crank]

deisle oil that is not synthetic that cost to much .

[Shaun]

It is true that Comp Cams swears by Rotella diesel oil for cam break-in. This is because it has the high pressure lubricant necessary for flat-tappet cams(zinc-phosphate). It is not a bad choice,by any means(unless you are running a roller cam).
Ehostler has a very good point,too. The Rotella(Delo 400 and others) will break down quicker,meaning changing the oil more often.
The synthetics that are on the market today ,like conventional oils,have different ratings. Look at Royal Purple for example;they have energy conserving synthetic oil and they have flat-tappet(hyd.,or solid lifters-no roller) friendly synthetic as well(they call it racing oil).
The fact is,to protect a flat tappet cam in the ever changing world of government regulations(with their cat. converters getting burned up by the zinc-phosphate) and the emission standards getting tighter,you have to make sure you protect your flat-tappet cam with a high pressure additive like zinc-phosphate(which is still in diesel oils). It can be bought from Hughes Engines as an additive to any oil,as well as from your local auto parts store.
I hope this helps

[dodger1]

Jack, Shaun touched on a key subject here, emissions. Apparently some of the detergents and other lubricants (zinc phosphates in particular) have been modified and/.or removed from current oils for that reason. Personally I've been using Pennzoil 15-40 LongLife diesel rated oils since I built both the (non-cat) 360 and the old air-cooled Suzuki. Absolutely no complaints. Yes I change it frequently but that's cheap insurance anyway.

[Jack_440 Savoy]

Crank, What kind of engine do you have, Gas or diesel ???

[dodgedart360]

I was told a few years back that deisel was better for your engine if you were doing big miles. That is constant usage, however if it was to be used just to run down to the corner store and back forget it, the oil needs to be at operating temp. to give any benifit.
My .02 cents worth.

[gotcha]

Many good posts and info on this thread. The difference here is the camshaft vs. main bearing oiling. The notes about the synthetics and rotating the lifter are correct. Rotella is excellent in new engines for camshaft break-in. There has been a huge increase in aftermarket camshaft failures since the increase in oil options. Straight weight 30....good old oil works fine. No fluff...no foo foo. Royal Purple is the absolute best overall for a street strip car after camshaft break-in..... repeat....after camshaft breakin. That is simply my experience and thoughts. About 10 years ago I tested (drag strip timeslips) straight 30...10-40, and Amsoil in my 77 Volare RR with a mild 451 stroker. The car showed about 1.5 tenths increase overall in ET with Amsoil in the trans, in the Sure-Grip, and the engine. No problems until I started the brand new Hughes camshaft on Amsoil, leaving for the ET finals that year. 6 test passes and ET dropped like a rock...on every pass. This was an 11.00 flat street car...that I dialed in at 14.00 flat on the first competition pass. Checked everything....timing...fuel....etc. Got the car home...took it apart and the lobes were rounded off. 7 passes total on Synthetic. My bad. Just a bit of real life info. Also, another bit of advice...run the LEAST amount of valve spring you need. The triple, extra heavy duty, battleship springs require huge amounts of HP to open and close. This is much easier on Hydraulic cams....

[Crank]

Originally Posted by Jack_440 Savoy

Crank, What kind of engine do you have, Gas or diesel ???

its gas a 83 chevy pickup i restored a few years ago, it had a smashed front end and rust holes so big you could stick your hole arm in it.

[ehostler]

Now you done it!!! This forum is for MOPARs! Your question is in relation to a Chevy. You shouldnt have said that it was about a chevy, now I have to move the thread to Off-Topic.

MOD

[ehostler]

Oils rated for economy are actually targeted for todays engies that have cats behind them. If you have a bad ring or valve seal, you will burn some oil. If that oil has zinc, it will kill the cat. If the vehicle has under 120,000 miles on it, the manufacturer must replace the cat under the emissions warranty. The manufacturers worked with the lubricant companies to remove the zinc, so it wouldnt destroy the cat. As modern engines use rollers instead of flat tappet, the zinc is not required.

Now that diesel engines are begining to get cats, we may begin to see zinc being removed from diesel oil. Rotella-T has modified the properties of the oil; however, it is supposed to still protect the flat tappets.

[djswwg]

Another thing to remember is that most "hotrod" or "car guys" usually change their oil and filters more often than the average car owner so not as much detergent type oil is needed to keep the engine clean. The less detergent in a performance motor the better, as detergents are not lubricants........................djs

[Crank]

Originally Posted by ehostler

Now you done it!!! This forum is for MOPARs! Your question is in relation to a Chevy. You shouldnt have said that it was about a chevy, now I have to move the thread to Off-Topic.

MOD

Sorry man but in my deffence i only have 750 bucks into it total paint and all so i use it to go get Mopar parts at swop meets and stuff,and it is my first chevy in 32 years of driving.it don't burn oil and keeps 30/40 oil presure , no lifter noise i love that oil i beat that truck daily and haul over the limit in pay load at times .i have to drive something in the winter why get salt on a mopar when i can use a chevy?

[Bigshot]

Originally Posted by Crank

why get salt on a mopar when i can use a chevy?

I think that will justify showing that you drive a chevy.. Very bad thing around here.

[ehostler]

That's not a good enough excuse... I drive my MOPAR in the snow, salt, sand, muck all of the time. First it was my '96 Ram and now it will be my 2006 Ram.

[dust]

Hot Rod's take:

http://www.hotrod.com/techarticles/e...l_summary.html

I use diesel 15W40 in my Kawasaki flat tappet engine with no problems.

[MrChemist]

Ahhhhh….It’s so refreshing to hear from closed minded people…... I guess I won’t mention what I drive when I’m not driving my weekend warrior/race car for fear of having my account locked out.:f

[ehostler]

Hello... If I were being serious, don't you think that I would have moved (or removed) the thread already??? Maybe if you had removed the blinders and thought about it for half a second, you would have seen that I am only kidding.

So, do you have anything worthwhile to contribute to this thread or were you just going to complain?

[MrChemist]

My apologies for the “closed minded” crack…I’m nearing the end of what looks to be a 19 hour work day (although that is not a good excuse)…I probably should not have sat down at the computer because I was a little too grouchy.
:w

[RAM1500]

Originally Posted by Bigshot

I think that will justify showing that you drive a chevy.. Very bad thing around here.

Hmmmmmm I'd hate to think what would happen if you guys found out about the 496 big block chevy that dad and me built to race.

[wilks3]

If you email Royal Purple you will get a very good reply of what to use and what not to use. I know somebody will say, "well thats their product what else would they say". They tell you don't use the energy star marked oils. Try it, its very good info. I will for sure be using the 15w40.