There has been some talk about converting over to Diesel Engine oil. There is a new oil out that is called Castrol Tection Extra in SAE 15 W 40. And of coarse the old stand by Rotella. And with the post from Comp Cams recommending the Rotella Diesel engine oil for cam wear and break in.

Now to the question should I switch from my old Castrol 20 W 50 to the Diesel Oil? And if so why?

Thanks to everyone that is well Oiled

 

Why are you using such thick oil?

 

Thick lol. I am in South Texas. And the Castrol has worked great in the past as far as break down. I have a new big block with a solid flat tappet cam that I would like to live for awhile. . So I am looking for educated opinions on oil.

I guess a little more info. I have run every dino oil out there and found Castrol to work the best under hard use. Both in viscosity break down and maintaining oil presure. I have run it in my old Saburban that now has over 330,000 Mi on the OD and still runs great. But with the way oils are changing I am thinking of switching to the Diesel engine oil for longer engine life under hard use and to extend the life of my cam.

 

I wouldn't use oil for diesel engines in a gas engine. The standards for oil get better and better. You should be able to get 300,000 miles out of that new BB...just change it often.

 

Shake,
Look at your oil container and you will see that, apart from the 15W40 or whatever, there are two letters next to it. More than likely they will be "SG" or "SF" or if it's diesel oil then "CD" or "CE" etc. The "F" and "G" indicate the latest standard for engine oils, and as a new minimum standard is introduced, so is a new alpha suffix; the next one will be "H", then "I", "J" etc. The prefix "S" stands for "SPARK IGNITION" and the prefix "C" stands for "COMPRESSION IGNITION".

What this means is that oil manufacturers design two types of oil, one for petrol engines and one for diesels. Different additives are used to be compatible with the type of fuel and therefore the ignition process involved. If you use an oil designed for diesels in a petrol burning engine, then you might experience abnormal wear in certain parts of that engine, because there were no additives in the (diesel) oil that would be found in a petrol engine oil.

To summarise, I think that the oil manufacturers know a lot more about engine wear than we do and design their products accordingly to minimise that wear. If you go ahead and use a diesel oil in your petrol engine, then caveat emptor .

Regards from Down Under

aussiejohn

 

Rotella is relatively inexpensive when compared to many brand name "car" dino oils. Go look on the shelf at the store ... at a jug of Rotella ... in addition to those letter designations ... Rotella label clearly states for use in BOTH gasoline and diesel engines (the Castrol Tection label may be same ... dunno). Just keep in mind that those metal wear additives MIGHT, just MIGHT interfere with exhaust emission sensors/convertors ... I'm NOT saying they will ... only that they might. I've been considering this diesel oil thing for some months ... with NO sensors/convertors in my 71 ... my choice is clear for next change.

 

There again, you should realise that it doesn't make a bit of difference what oil or what grade you use - the engine will either outlast the car or it will grenade due to some non-lubrication related failure.

Anybody know of any documented case of engine failure due to the use of 'poor quality' oils? I sure don't and I've been in the engine manufacturing business since 1978.

 

For what it is worth, I know that Caterpillar Inc., a deisel engine mfg. was the first company to test oils and set standards for oils used in their engines. When the oil companies were sufficiently educated as to the specs different mfgr.s needed for their lubricants Caterpillar turned that responsibility over to them and they have improved the process ever since.
For a while I used engine oil that was designated for use in both diesel and gas engines without any problems. I switched to Castrol only because I relocated and could not get the oil I had been using. Again for what it is worth.
Bernie

 

Not an expert but I made the switch to Castrol Tection 15-40 from Castrol GTX 10-40 after reading many posts by knowledgable folks. The advantage of "diesel oil" is that the detergent package is more well suited to carburated engines than the "S" rated oils which are designed for modern fuel injected engines. My L-82 has always used the first quart in 800-900 miles-even from new according to the original owner. When re-sealing the intake manifold in yet another attempt at reducing this consumption I noticed some build-up on the backs of the intake valves. My plugs read good and the engine doesn't smoke so I believe the valve seals are good. The rest of the engine is very clean internally so a change to "C" oil type seemed a reasonable experiment both to clean up those valves and maybe to reduce oil consumption due to the 15w viscosity when cold. The only other change is that I don't idle the engine for warm-up as long - only about 5 minutes in this test. Result: first quart lasted ~1300 miles at which time it was changed. The oil "seemed" pretty black for the miles but that might be wishful thinking. It's a short test so far but I intend to continue using it next season.

 

The CI-4 Diesel Rated oil has extra wear additives that are not found in gasoline engine oils for several reasons. One reason is that diesel engines operate at very high compression ratios so the loads are higher. This is not the most significant reason.

The biggest reason for the better additives in CI-4 Diesel rated oil is that the additives in the Diesel oil are harmful for your catalytic converter. That is why they have been taken out of your gasoline engine rated oils. Remember, nobody has sold a non-cat gasoline car for around 30 YEARS! That is why the additives are out of the gasoline vehicle oils, even the highly marketed boutique (expensive) ones.


If you have no cat, the CI-4 Diesel rated oil is better.

-Mark.

 

Shake- First off you should be using Amsoil. It is by far the best oil on the market. I have a fleet of trucks that run Amsoil and some of them have 100K on the oil with filter changings on the block and Aux. every 20K and 40K respectively. If you don't believe me check up on it. As far as diesel oil of you want that viscosity Amsoil makes an oil for diesel/gas engines. I run it in my '03 2500HD silverado.

 

I agree. http://www.atis.net/oil_faq.html

 

Bottom line, you need to look at the back of the bottle at the API star. The lastest code is SL, EPA has consistantly been reducing the amount of phosphates in the oils, and coolants, which is part of the "wear packages" or incredients.

Motorcycle manufactures have voided some warranties based on the grade of oil that was used in a bike. BMW, Ducati, and I believe HD has released bullitens discussing the importants of using the correct class of oil in their bikes.

Ever noticed the increasing amount of oil choices lately? Truck oil, long mileage oil, motorcycle oil, etc. Each of these has a different class rating on the back.

We need to look at the bottles closer to make sure the correct rating is being used. As aussiejohn already stated, oils ain't oils. We can no longer use the same oils as our daily drivers.

Later.

 

 

Thanks for the positive endorsement.

Not trying to jump into the debate here, but to share some info, AMSOIL's available diesel oils for those that are interested:
Series 3000 Synthetic 5w30 Heavy Duty Diesel Oil
AMSOIL Synthetic 5w40 European Motor Oil
AMSOIL SAE 15w40 Heavy Duty Diesel Oil

 

I'm casting my vote for synthetic! Redline or Royal Purple if you can afford it, Mobil 1 for those who can't (me).

 

Thank you for all of the info people. But it seems that many are still on the fence as to the use of Diesel oil as compaired to regular motor oil. And then there are some that feel you should just add the Chevy EOS to the oil?

 

Are you an Amsoil dealer/distributor? It seems that the last couple of Amsoil recommendations have come from people with alleged large truck fleets, one of which admits to being an Amsoil dealer.

I believe that as long as you use the correct rated oil, dyno or synthetic, change at 3000 - 5000 miles, in your street car, you should be ok.

I'll be dead 20 years before my 'vette goes 100,000 miles and I do not change oil at 20K, so what is the point of using that overpriced stuff?

 

BTW, I did use Valvolene racing oil (high zinc) and GM EOS for cam break in and for the the next 2 oil changes (after break in and @ 500 miles). Will go back to Castrol 10w-30 at next oil change.

 

I believe it was Consumer Reports a few years ago that did a scientific analysis of oils, including Mobil 1 and Amsoil. If I remember the gist of the article, it said you should use a name brand oil, change it and the filters regularly and have fun with your vehicle. Again, synthetics, especially Amsoil, did not do any better than dinosaur based oil, especially considering the cost. Note the word scientific. Giving a one person testimonial does not make it a viable statement. I know a guy that got shot in the head with a large caliber hunting rifle - and survived. I don't think I want to use his case as a testiment to getting shot.

There HAS been some discussion of diesel oil in gas engines. As the owner of a diesel, I can tell you that these oils do work well in older gas engines. Just like regular oil will work for a limited period of time in a diesel engine. The difference is the ability of a diesel oil to suspend particulate matter and still effectively lubricate. Todays gas engines don't have near the amount of crud in them after they have been run. For instance, my wife's Lexus won't turn the oil even slightly dirty for at least 3000 miles. At the 5000 mile oil change interval, it is like dark honey - no worse. Oth, my Mercedes diesel gets black just on a trip around the block. Within two miles it is sooty but still protecting. Fwiw, I use diesel oil in my 72.


I hope the poster with the fleet of trucks is not suggesting running Amsoil for 100K with just filter changes. If that is correct, then I would run from that advice. If this person is in the business of selling the product, he should state that in his posts.

Gary