Been running Rotella 15/40 dino ever since I got my truck, ran it in my 6.9 also. I notice a lot on this forum running full synthetic, and the cost of it has gone down so my oil change is coming up and I am thinking about switching. Any pros or cons? Presently my truck sees under 10K/year about 1/2 city and 1/2 highway. It has 165K on it and uses little to no oil between changes.

 

The only con to synthetic is the price. I go 5000 miles between oil changes, but I wouldn't go any longer - our HPOPs make short work of the oil with all the shear that takes place. Many will swear by doing an oil sample and continuing on - but I have yet to change the oil and not hear the injectors quiet down in there when warm.

 

A lot comes from personal choice and how much your pocket book can stand. If you live in a cold climate then the viscosity ranges available with synthetic can help a lot with the engine romping. It doesn't get cold enough at all here for me so I just run Dino oil.

Synthetic is certainly not going to hurt anything, give it a try and see if notice any differences in the way the truck runs. Then you can decide if it is worth the extra cost to you to keep doing synthetic changes or if you feel you just want to go back to Dino.

 

Oil, Dino or Syn? Each has it's cult followings and naysayers.


www.bobistheoilguy.com has more information than one could want. There is also the "Oil Bible" available for download.


Fact: Many use lower multi-grade such as 5w30 and report much easier starts with the HEUI in both cold and warm weather.


I would say, IMO, the molecular type used is much more removed than the doing scheduled oil changes without fail to ensure longevity.


Oil, its type and make up far exceeds the number of threads in any forum I have ever been associated with.


And, for the most part, it appears to be individual preference by the person rather than any claimed results of the oil itself.


Keep in mind, whatever you choose, neither provide longer change intervals without the use of approved filtering systems.


I run Dino in my 4-wheelers and Syn in my Motorcycles. Motorcycles merely due the heat resistant's and breakdown of oils in Air Cooled V-Twins - That's the only reason I use it.

 

I was doing the 5K interval as well and last time I went 6, then sent in a sample. Blackstone said to go to 7500 next time. I am now a bit over 6K. I semi reluctantly ran it to Mexico last week with that oil but I am not feeling good about it and will change it before my trip to Santa Fe next month.


I hear what you are saying on the injectors, I may be able to hear a difference but it might just be placebo too. Just like my mixture of Stanadyne and Optilube, seems quieter but who knows?

 

I run T6 and my change interval is 15k. My problem is, I don't put that many miles on it so I change it about every 2 years or so. Additionally, I live in an area that really does not have "winter" in the literal sense as it ranges from the high 90 range for the summer and mid 60 range for winter. Here is what I use for filters. I change the 7405 each time and the EaBP every other time.

 

I run dino. I ran synthetic for a short while when wally world had it on sale for the same price as dino, but when the sale ended, I went back to dino.

 

I have run a several different brands in synthetics and dino, I did the extended oil change interval thing when I was running both with used oil analysis and they had me out at about 9500 miles on T5. My injectors went bad at 155,000 miles and I have no proof it was the sole cause, but the extended oil change interval couldn't have helped....

I run synthetic T6 now, especially in winter, it really helps with the romps. That being said, in the warmer months, I wouldn't hesitate to run either.

 

Sounds like dino may be the way to go for me, no winter weather here to speak of.

 

Change it and use the motorcraft FL1995 filter at 5K and you will be fine.

 

Probably overkill but I've been changing at 5-6K and using the expensive Fleetguard LF 9027 venturi bypass filter.


https://www.cumminsfiltration.com/pd...LT36043-GB.pdf

 

I also run t6 and fl1995. 10k. Usually two summers worth.

 

Any suggestions on a time interval for oil changes for a very lightly-driven truck? My 2001 7.3 has about 115K total, mostly from the previous owner. Since I bought it, I've been driving about 1500 miles/year, mostly pulling a GN horse trailer. I've been using dino 15W-40, but after starting to read this forum a few months ago, I'm probably going to switch to T6 5W-40 to try to eliminate some cold-weather romping (not extremely cold.. I'm in KY).

When I first bought the truck, I used to change the oil twice/year, even though that was probably less than 1000 miles between changes, just because I'd seen so many maintenance schedules that recommended 3K or 3 months. Last couple of years, I got lazy and only changed once. After seeing a couple posts here from people going 2 years between changing, I'm thinking I could get even lazier.

Is there a maximum time interval after which oil starts to break down even after little use? If I dump in T6 this summer, would it be safe to go as long as 4-5 years between changes, if that means 6-7K miles?

 

Like you, I switched to synthetic due to romping on Delo 400. If it weren't for that reason only, I wouldn't have made the switch since it doesn't get that cold here.

Also, I put very few miles on my PSD. Last year I barely put 2k miles on it, and this year looks like it will be even less. My last Blackstone OA had just over 5k miles on it, and was 2 years and 3 months old. I posted a question to Blackstone about it when I sent the sample in, and they said it was a non issue. My report came back great. Unless severely contaminated, oil in the crankcase will be fine for a few years. That put my concerns to rest.

 

Switching from Dino to synthetic - my first question would be:

What problem are you trying to overcome by switching to synthetic?

One good reason would be for cold starting conditions, another would be heavy duty service in extreme hot weather.

But definitely not for extended drain intervals - synthetics on average do not hold additives (the good stuff) as well as a dino or a synthetic/dino blend.

If you do a quick search on Bob is the Oil Guy site for virgin oil analysis reports you can see the difference in additive packages.

A synthetic blend is what I prefer for 7.3L diesel engine oil, get the best of both worlds...Full synthetics really shine in gear cases - they are not subjected to the contamination of combustion by-products.