Engine/Transmission (1994 - 1998) synthetic engine oil

[WoodJ]

I was thinking of going to full synthetic engine oil. Is there going to be any affect on the engine or seals. Will it be worth the money? Thanks for any info.

 

[fest3er]

I was thinking of going to full synthetic engine oil. Is there going to be any affect on the engine or seals. Will it be worth the money? Thanks for any info.

Harm the seals? No. Uncover latent age-related problems? Possibly.



How many miles on the engine? Has it ever run hot enough or been exposed to other conditions that could harden the seals? Has the oil been changed regularly over its life?



Lube that runs low on total base number (TBN) additives can allow acids to form in the oil; acids lead to sludge formation. Over time, sludge can 'seal up' seals (and other things). A good synthetic lube can clear this sludge, and if the seals have hardened, they can start to leak.

 

[KOG]

I have run synthetic in all of my high annual mileage gas engines for decades. Diesels are a somewhat different ball game. Fuel dilution requires more frequent oil changes with diesels and the larger oil capacity considerably raises the cost of changes. Thus I run conventional oil in my bulldozer, backhoe and two Dodges. Figure a 1-3% improvement in fuel mileage and sue that the see if synthetic will be saving you money. In the case of the Cummins you probably won't see any increase in engine life because the thing will last longer than you'll drive it anyway.

 

[CKelley1]

same here kog our 91 has 1,050,000 on it now with delo 400, still not using oil. we do not sell our trucks or heavy equipment and this is our 43rd in buisness. the drive train on our 1967 d8 got so bad that i parted it out last year the motor had never been overhauled and was not using any oil

 

[CKelley1]

i just got a volkswagon 2009 tdi and is time for first oil change, it has a dpf on it so i have to use cj4 it calls for 5w 30 synthetic i think i am going to use rotella t 5w 40 in it. kind of sad to be changing oil out with $20 a gallon synthetic beside a 55 gallon drum of delo 400 but at least it's only about 1 gallon

 

[robbiesworld]

I personally dont think synthetic is any better than good dino, I run Delo and change it every 3000 or 10,000 miles depending on how lazy I am. I wouldn't waste my money on synthetic.



I also think synthetic ATF is the fastest way to burn up a transmission.

 

[HBarlow]

Synthetic oil may, or may not be, any better than conventional motor oil. Opinions vary.

The second question you asked was about operating cost. The key factor, in my opinion, is your owner's manual and any communication from Cummins will clearly state that using synthetic motor oil does not permit extending oil change intervals.

Synthetic oils cost considerably more than conventional oils so your cost to use synthetic will be considerably higher and will provide no measurable benefit.

I am driving my third Dodge-Cummins after putting 325k miles on the first one and 230k miles on the second one. I have never used anything but conventional motor oil and have never experienced any excess oil consumption or mechanical engine problems.

It's your truck, your wallet, and your choice.

 

[Skydiver]

Harm the seals? No. Uncover latent age-related problems? Possibly.



How many miles on the engine? Has it ever run hot enough or been exposed to other conditions that could harden the seals? Has the oil been changed regularly over its life?



Lube that runs low on total base number (TBN) additives can allow acids to form in the oil; acids lead to sludge formation. Over time, sludge can 'seal up' seals (and other things). A good synthetic lube can clear this sludge, and if the seals have hardened, they can start to leak.

Very true fest.



If you know your engine will never run hot then stick with dino oil. I only run Rotella fully synthetic because it will protect the bottom end if my engine looses its coolant. Sure, any engine can be ran till it siezes. I hope that day never comes.



I ran delo 400 until 135K. At that time I began using Rotell synthetic and went from changing every 5000 to every 10,000 miles. With that being the first time I have ever allowed an engine to run 10K on an oil, I sent a sample off to Blackstone labs for an oil analysis. The report came stating that my oil was not yet ready to changed. I use LF3552 fleetguard.

 

[CKelley1]

the synthetic is not any better than dino. the best way to chang oil is to test every 3,000 miles from 6,000 miles up until the soot loading or additive package is low blackstone will tell you when it is. from there you do not need to test again for about 200,000 if it is still the same that is the last test you need to make. on the 04. 5 up the soot is the limiting factor because of the in cylinder egr used on them. we have several dodges in our fleet from 89's to 07's i use the lf16035 filter on all of them

 

[bheiting]

In John Martins Technical Topics articles in TDR issues 56-58 he says that oil additives
are more important than base stock. That includes synthetic. If you are driving where
the temps drop below 0, then use syn.

 

[RyanStewart]

Its worth it in cold weather. You can really tell the difference when starting. Otherwise its probably more expensive than its worth.

 

[Vaughn MacKenzie]

I like running syn so I can be lazy and not have to change oil very often :-laf

Changing every 15,000 miles with one mid-change filter replacement has worked great so far, oil samples come back excellent. Going long on oil changes isn't a good idea unless you sample and the results come back good.

I like syn for an extra measure of protection due to higher breakdown temperatures as well as increased flow on cold starts for quicker oil pressure.

 

[Breed]

I run Rotella fully synthetic in my 98 12 valve, or AMSOIL, I really like them both, I bought the truck new in 98' and I love it and will never trade it off. The truck has just turned 90000 on the clock and runs great and most of the miles have been towing a 10k 5th wheel RV. I did put on a Pac brake and killed the KDP, put on a starter from Larry B and also a wiring package from Larry B, rebuilt a leaky vacuum pump with a kit from Pete Gould and it works great! The problem with my 98 is I don't use it a lot, only to tow, it's a great truck.

 

[moparguy]

Just an opinion (backed by personal experience), most all of us change oil more often than necessary. I can dig it up if needed but I posted a couple of years ago about my mileage test using Delo 15w40 and a Frantz by-pass filter. Since new my truck has used a qt. of oil about every 4k miles. So topping off takes care of my replenish additive package needs. I sampled (JohnDeere lab) every 5k miles, at 21,000 miles with a sample coming back saying good to continue running, I broke down and did a oil change. This was with 2,500 mile Frantz filter changes and the same Fleetguard filter.



I now change around 10k with no guilt at all. I do have a stash of the older CI4 Delo I'm still using and at 250k, the old 95 seems happy. When I pull the valve covers to adj. valves, it's as clean as can be.