Switching to synthetics?

[Darel]

I'm just wondering if diesels are like gas engines in that you don't really want to switch to synthetic oil after running dino juice for a while (a good cutoff I use for gas engines is 30,000 miles). Do the diesel seals run into the same problem, where they swell, and then crack and leak? Or can you just throw synthetic in anytime, due to the heavier-duty nature of everything on our trucks?

 

[Dieselnerd]

I switched to Amsoil in my engine at about 65,000 miles. I used the Amsoil engine flush to clean out the motor before the change (came out very black and dirty) and have no leaks anywhere. I've heard this story before and I don't think there is much truth to it. Maybe an old gasser that's worn and slightly leaking already, synthetic does flow easier and in that case might get by worn seals. If your motor isn't dripping now it won't leak after synthetic either.

 

[RHARVEY]

My truck had 146,000 on it when I switched to Series 3000 5/30 Amsoil and had NO problems... . Now I have over 20,000 on the oil and still no problems. I replaced the valve cover gaskets back in the spring and I got a big surprise. . under the covers and the valve train was so clean that I would have bet it was a new engine.

With changing the dino oil at the regular times and also filters. . it could look the same. .



Rick

 

[redram]

Originally posted by Darel

I'm just wondering if diesels are like gas engines in that you don't really want to switch to synthetic oil after running dino juice for a while (a good cutoff I use for gas engines is 30,000 miles). Do the diesel seals run into the same problem, where they swell, and then crack and leak? Or can you just throw synthetic in anytime, due to the heavier-duty nature of everything on our trucks?

Darel,



I'm curious where you determined this interesting, although incorrect, arbitary 30,000 mile limit for not switching to a higher performance motor oil?



I have used synthetic oils for 18 years and make my living as Manager of Technical Services for a small privately owned manufacturer of synthetic lubricants. I personally know of gas and diesel vehicles that have benefitted from switching to the higher performance of a synthetic motor oils even though the odometer was in excess of 200,000 miles.



I do not recommend changing to a synthetic if the candidate engine is consuming more than a quart of engine oil per 1000 miles. The added cleaning ability of the higher performance oil has a 50/ 50 chance of decreasing the oil consumption but also has a 50/50 chance of increasing the oil consumption due to cleanup and exposing seals that have been damaged by the poor lubrication of the . 79 cent / quart oil.



Where did you get this information about not changing to synthetics after 30,000? I've never seen it published by any of the manufacturer's of synthetic lubricants.



By the way, traditional mineral oils and "synthetic" motor oils are fully compatible and can be mixed and interchanged without any harm coming to an engine. Now, it is not the smartest thing to do for your engine. Probably not. It might be similar to running four different brand tires on your truck with different tire tread patterns. As long as the tires hold air, the car / truck will run okay. However, under braking or rain situations, the handling could become less than optimal, as an example.



As far as mixing synthetic motor oils with mineral motor oils, heck, the major oil companies offer it in the stores as a partial or blended synthetic so it's not something to worry about.



What is important is that the proper grade (viscosity) and type of oil get used in the application. In the case of the CTD, the recommended grade by Cummins is a 15W40 viscosity having API ratings of CF-4 minimum for the older 12 valves and an API CG-4 minimum for the newer 24 valve ISB's. Ideally, you would want to use the newer API CH-4 rating which most diesel engine oils should meet.



To learn more about API, www.api.org has a consumer section that explains about the API service classifications.

http://api-ep.api.org/filelibrary/ACF1E1.pdf



Do Not use Mobil 1 or Castrol Syntec in your truck with a CTD as these are not rated for diesel engines. These two are synthetic type motor oils rated for gasoline service not diesel. Use oils that are CH-4 rated such as Delvac 1, Delo 400, Shell Rotella T, Royal Purple 15W40, Lubrication Engineers, Schaffer, Amsoil, etc... ...

 

[Tim1]

Hey Redram, are you saying that by running Delo 400 mineral oil at a change 0f 3000 miles is by far not as good as running Amsoil Synthetic oil for 10,000 miles. Filter changes at 3000 miles on both. The truck has 120,000 miles on it and does not leak or use a drop. Thanks for advice. Tim

 

[SlyBones]

Tim1, I did back to back oil analysis of Delo 400 and Amsoil in my truck at 4000 mi sample. Analysis were the same. If you are gonna do 3000-5000 mi oil changes save yourself the money and stick with the delo.



Now I did not do the test but I would guess that 20,000 mi intervals on Delo 400 and Amsoil ( with proper filter changes ) I would think the TBN would have wore out on the Delo, and Amsoil would still be OK. Hard to say about wear metals and that.



When I switched to the synthetics I did not do the flush. I hear that is a PITA. So instead I did several filter changes with in the first few thousand miles. From there its regular filter intervals.

 

[Tim1]

Thanks Slybones for the reply, Ive used Delo in all my equipment and rolling stock for 20 years and always change at 3000 and never had any problems. I've opened them up from time to time with no sludge. Just want to stay on top of latest oil technology to see if I needed to think about changing. Thanks again! Tim

 

[Darel]

Redram,

You're absolutely right, the 30,000 mile deal is compleletly arbitrary. For my own vehicles that's the point I wouldn't switch. My reasoning is the same as those you provide, the extra detergency of the synthetic, plus the fact that it does have an easier time slipping past already-worn seals. But can you really tell when that is on a vehicle that isn't, like you say, consuming oil or already leaking? Probably not, so that's my own personal cutoff, just to be extra-safe. I'm sure any actual problems wouldn't occur until a much higher mileage, but why chance having to pull my transmission and transfer case to replace a leaky rear main just to stretch my oil-change intervals?

To everyone who replied, thanks. It appears as though I should have no problems switching over to synthetic oil in my CTD.

Darel

 

[redram]

Originally posted by Tim1

Hey Redram, are you saying that by running Delo 400 mineral oil at a change 0f 3000 miles is by far not as good as running Amsoil Synthetic oil for 10,000 miles. Filter changes at 3000 miles on both. The truck has 120,000 miles on it and does not leak or use a drop. Thanks for advice. Tim

Tim1, I don't understand your question Tim.

I was answering the original poster's reference to not switching to a synthetic because of some arbitrary mileage figure.



Regarding your your statement if I understand it ... . using a high quality mineral oil such as Delo 400 (even though they are claiming it is a synthetic because of the use of Group II or Group III basestocks, in is still a refined crude oil) and changing the oil and filter every 3000 miles I would expect the engine to be in good shape and run without any problems. As far as running the other product and would it perform better or worse, I don't work for the other product so I'm not going to get into a symantics issue here.



What I will say that using an API Licensed CH-4 Synthetic oil will generally out perform a high quality mineral oil in high temperature depsoit resistance, low temperature fluidity, improved lubricity for fuel mileage or horsepower, and generally less wear. How far you choose to run the higher performing products is something that will vary with each application.



In general, changing a high quality product like Delo 400 for instance, at 3000 miles is a VERY conservative interval and could possibly go double that drain interval or longer without consequence to the reliability of the truck.



Changing a properly formulated synthetic rated for our trucks at 10,000 would generally be VERY conserative for these products, assuming that the oil filters were also changed at the same 3000 - 6000 mile interval as with the mineral oils.



I also have a truck with 135,000 that has had synthetic in it from 5K with oil changes at 12K changing the oil filters at 4K-6K. It does not use oil or leak oil. Last oil change was increased to 22K on the oil but I had added a bypass filtration system to help remove the soot particles.



Hopefully,



I've added information



REdram

 

[FD5]

Bought my truck with 224k miles, changed to Amsoil 15w40 at 226k. Truck currently has 254k with no leaks and oil samples at 12k intervals. Use what makes you happy.



John Hatch

 

[Steve Roseman]

When synthetics were first introduced they had problems with seals drying and cracking. The dino oils had acids that would keep the seals soft and pliable, when someone would switch to synthetics they would end up leaking oil.

The oil makers have long since found a remedy by using additives in the synthetic oil to accomplish the same thing.

There are a lot of old tales that had a beginning with some truth to them but have been outdated, kind of like letting your diesel idle all day or night.

 

[Tim1]

Hey Redram, thanks for the reply. I think that I will stay with Dello 400 at 3000 change on both oil and filter. But you know, I will change to the Fleetguard Microglass filter after researching the posts on the subject. Oil and filters a very inexpensive! Tim

 

[redram]

Delo 400 is an good oil and combined with the Fleetguard Microglass or Stratpore filters, will provide you good service changing them at the conservative drain interval of 3000 miles.



Everyone reaches a comfort zone for personal maintenance habits and "change" is a very hard thing for people to do, no matter what the change is. Stopping smoking or drinking are two examples. Most will acknowledge that smoking is not good for long term health but few smokers are able to make the change to improve their long term health situation.



Using a higher performance product such as a properly formulated deisel engine oil that yields less wear, less emissions, higher fuel economy, and the ability to reduce the amount of maintenance required (number of oil changes) is one of those changes that is not for everyone because people resist "change" or newer technology in general.



But, different strokes for different folks. Nothing wrong with that.



Hoping everyone has a safe New Year's Holiday!

 

[Tim1]

Redram, will the stratapore filter work for the first gen? I see the second gen using them, but no listing on Genoes for the first gen. Are they superior to the microglass? Thanks Tim

 

[RoryTek]

Here is something else to think about, by using synthetics and extending your oil change intervals, you'll be doing the environment a favor. Now don't get me wrong here, I'm not a tree hugger, but you gotta ask yourself do I want to climb under my truck every month or 3k and possiably strip out the plug, spill oil from the filter (yes I know about using a zip lock baggie trick) and running to AutoZone, Checkers, Kragen or PepDudes and spill my waste oil all over their clean floors. I know I exaggerated a bit, but you get my point.



May Your CTD Live Long