Oil change frequency with Synthetic oil

[pmsmechanic]

The service manager at our local John Deere tells me that if you use John Deere's synthetic oil and their filter you can go 50% longer between oil changes. So 300 hours would become 450.

I know from testing that 25000 km/15500 miles is too long on my Cummins but 15000 km/9300 miles is quite ok

 

[newbury]

Thanks for all the input. I understand the concept of "cheap insurance", and $100 for an oil change (10 gal T6 plus filter) is not that cheap (but cheaper than a new engine of course). I'm going to find someone who does UOA's. I guess my thinking has been tarnished by my dad, who (many, many moons ago), worked for Mobil Oil on the Mobil One project...He was a "beta tester" with the cars we had at the time, and they did those UOA's periodically...I distinctly remember him talking about going 15,000 miles or more, with the results showing pristine oil properties with the stuff. He said changing it every 3000 miles was pouring money down the drain.

Diesel's are different and T6 is probably way ahead of Mobil One, but the UOA should tell what if anything might be going on.

Uh, 10 GALLONS of T6? Didn't you mean 10 QUARTS?

And I would say your memory is not tarnished, trust your dad. For example my '09 VW TDI has a 10,000 oil/filter change recommendation from the factory.

 

[Deere Dude]

I change yearly because it is often less or abut 100 hours anyway.

The problem I have is why put expensive synthetic in instead of like Rotella T 15/40 at half the price. I have no problem believing syn. is a better oil but it gets dumped at 1/4 of its useful life anyway.

 

[EddieWalker]

I don't put on enough hours per year to rely on that for when to change my oil. I do it every spring, just before it's time to start using it again. I tend to park it over the winter, and I feel that all those months of just sitting there leads to condensation in my oil pan, so before I fire it up again after sitting for that long, I change the oil and filters.

 

[newbury]

I change yearly because it is often less or abut 100 hours anyway.

The problem I have is why put expensive synthetic in instead of like Rotella T 15/40 at half the price. I have no problem believing syn. is a better oil but it gets dumped at 1/4 of its useful life anyway.

For me - because Rotella T6 5W-40 at $20/gal acts like a 5W at low temps and greatly reduces my concern about preheating the oil in the dead of winter. But it still acts like a 40 weight when hot. Except for my small engines I test for the useful life and it doesn't get

dumped at 1/4 of its useful life

Have you pulled a UOA on your yearly oil? How do you know it is at the end of it's useful life?

 

[Rock Crawler]

I can tell you this, I do annual Blackstone used oil tests on my fathers 1999 7.3L Powerstroke that he uses Amsoil oil and the Ae filters on. I sent one in just a couple months ago, he is at 3 years and 12K miles and the Blackstone analysis came back saying that we are good to go. The truck sits in a garage that is heated at 40F all winter, and he uses the truck occasionally (retired) but not daily. Next year, year 4, we will not pull a sample. Instead I will order him more Amsoil oil/filter and do a change out, then go back to annual monitoring to watch for any unusual changes. Based on time, he should be at 4 oil changes in this 4 year time, instead he runs a single change out over the entire 4 years at a cost of about $100, and I don't have to change his oil or dispose of it... Instead I use a used oil collection pump and pull oil in about 30 seconds and mail it off. It works. I don't think I would do it blindly, running an annual test lets you see anything changing so that you can get in front of it. He has 180,000 miles on the truck at this point and has been using Amsoil since the truck had about 30K miles on it.

 

[fishheadbob]

I guess my thinking has been tarnished by my dad, who (many, many moons ago), worked for Mobil Oil on the Mobil One project...He was a "beta tester" with the cars we had at the time, and they did those UOA's periodically...I distinctly remember him talking about going 15,000 miles or more, with the results showing pristine oil properties with the stuff. He said changing it every 3000 miles was pouring money down the drain.

Diesel's are different and T6 is probably way ahead of Mobil One, but the UOA should tell what if anything might be going on.

Definitely something weird with those Mobil guys. Uncle Jim was a refinery manager for Mobil and never changed his oil in his beater. Never. He dumped his '66 Mustang with 120,000 when the body and frame gave out but that little engine kept on running. That's a lot for cars of that era.
BMW says to watch the oil monitors on the cars' computer, ours never want a change (full synthetic) until 15,000 which scares me but we have 125,000 on this one, traded the last at 135,000 . ? I change at 10,000 .
I do my tractors at 100 hours give or take and have noticed the oil blackens up almost immediately; I really don't think color is any indicator of oil condition and could almost certainly go longer but like everyone else has said, it's cheap insurance.

 

[Rock Crawler]

I have a $53,315 MSRP new Ram Rebel with the Hemi 5.7L that is at 7,600 miles now with 17% oil life remaining. I have owned it since new (3-20-2017) and not had to do an oil change yet. I'll be right around 10K miles when it is due, and almost all of those miles is towing an 8K lb trailer. I bought the truck only as a toy hauler, I don't daily drive it. My suspicion is that these manufactures are acknowledging that todays oil is far superior to what was once on the market. I wouldn't see it being different in our tractors, but with my baby tractor holding less than a gallon, I'll likely change oil and filter every year regardless of hours. A guy I work with has a 16 year Kubota M series that he only puts around 50 hours a year on, he's changed the engine oil/filter 2 times so far... He is going way longer than I would because he discounts time completely and just looks at hours. He says he changes the oil "early" based on his use hours :laughing:

 

[Deere Dude]

For me - because Rotella T6 5W-40 at $20/gal acts like a 5W at low temps and greatly reduces my concern about preheating the oil in the dead of winter. But it still acts like a 40 weight when hot. Except for my small engines I test for the useful life and it doesn't get

Have you pulled a UOA on your yearly oil? How do you know it is at the end of it's useful life?

Why get an analysis done if changing it yearly anyway? If 400 hours is the useful life for synthetic and is dumped at 100 is seems like a waste to me.
I can understand thinner for cold climates works and 5/40 should help that and put your mind at ease and then should be used..

Even Rottella t 15/40 may have a lot of useful life even at 100 hours; I don't know. If changed yearly I don't worry about it, plus the owners manual says 15/40 is good for my temp ranges, but I haven't checked the book in a while..

 

[mike69440]

I would change the oil based on the manufacturers recommendation.

Being synthetic does not stop the oil from getting dirty.
It is your engine, and your $,$$$,,,

Oil will still get dirty, but Dino oil reacts with the dirt, Synthetic, less so. With a good filter, you can go longer. I go 100-200 hrs on motor oil, and double or triple on the OEM change interval on hydraulic fluids.