Home Forums Hunting & Shooting Hunter's Campfire Your experiences: synthetic motor oil and change periods

Yes, I also think Shell Rotella T6 is very good oil . It is on sale now with a rebate for 20 bucks for 10qt jug. The oil life computers tell me to change every 10,000 mi. almost like clock work but with full Syn. I run it to about 12,000. This time around I am going to get an oil test after 15,000 miles and I bet that oil is still very good. I used to run the best Amsoil in my 3/4 ton diesel ( Yah go ahead and sigh). I used the oil test every 15K. After 15K it was very good oil . I went to 32,000 mi. on the same oil and took a test. The test said it was still good oil I was hesitant to keep it though so I called the company and they went through the numbers and he re assured it was still very good oil. ALthoug he commented that very few people go this long with their oil. I went to 46,000 mi. on that oil. I took a test and they said it was still good but iron was getting high but recommended another $25 test in 7,000 miles. I just decided 46,000 was plenty long enough. I changed it and went 39,000 miles on the next change before they said it was still good oil but oxidation was getting a little high so I changed it. I changed filters every 15,000 miles. This is how long good full synthetic oil can go. I still have the truck , an 05 GMC diesel Duramax. It has 286,000 on it now. Bought it at 26,000 . It burned 1qt. in 5,500 miles when I checked last week. . The engine seems rock solid and burns almost no oil.. If I can get a 10 qt. jug of Shell T6, for 20 or 40 bucks ,I see no reason to get many oil tests cause a test is almost what the oil costs. However, a test tells me if I am leaking anti freeze, or if excessive dirt is getting in the motor from an air leak. Many talk about changing oil is cheap insurance, ,, or piece of mind but a test is the only way to go to know. Also , air filters are as important as anything and I forget about air filters all too often.

I follow the same procedure. With everything.

In fact, I usually change it early on my tractors and equipment. Pickups get changed when they tell me they need it.

That is my schedule with Mobil One. I've been doing so since the 90's

Mobile I, ten thousand miles.

What ever synthetic is on sale and a good filter every 5000 miles

1 qt every 3k miles - certainly is a BBC! That engine is working a LOT harder than everyone’s car. Off the cuff I would say 7k miles. I used to be in charge of a fleet of haul trucks at a mine. The best way to determine oil life is by actually pulling an oil sample and sending it in for analysis. We did just that on those big diesel engines and found we were able to extend the PMs by 20%. After that, the additive package in the oil, not the oil itself, started to break down. Test it. Everything else is just liquor and guessing.

5-6k with a quality oil filter and Mobil 1.

Synthetic pencils out in terms of time/filter avoided. I use either Chevron or M1, last Chevron batch went 10,000 on one filter, was black (7.3 Ford PS Dsl) but still slick on the skin test. Only place synthetic doesn't work for me is my old KZ rice bike, that has a wet clutch that slips with synth oil.

I have been using Penz Platinum synthetic for about twenty years in all of my old rigs. All my rigs are old. Momma's '05 Durango 5.7 hemi with 250 K on the meter got Mobil 1 the last couple changes just because it was on a great sale at Autozone

Oil changes happen every 5,000 to 7,000 miles. The longer duration between changes pencils out the additional cost of the oil.

The six liter in the recently purchased 01 GMC Sierra K2500 HD has a sensor unit on the engine which alerts the driver to oil break down and need for change. Since the truck was new in '01, that sensor has alarmed just shy of 4000 miles on Penz conventional. Since I have purchased the truck, we will see how far it will run on synthetic.

10K

Honestly think people are full of crap on oil issues.


Synthetic/dino, scheduled/1/2 intervals......


Seriously, who ever hears of oil induced failures anymore?
Working in a garage, had a contract with a snack food delivery outfit.
A guy comes in, he just "inherited" the newest panel truck in the fleet.
Running a Duramax, it had over 50k on the clock. With the factory
oil in it. The guy who got it new never had it serviced. When they pulled
the plug, the oil looked like STP stringing out the hole. But it was running fine.

Know guys that run beaters, myself included, that never change oil.
Maybe a filter and top off, maybe not. Cars they pickup cheap with
200k +/-. Then they get run for 30-50k more on the same oil.
Engine issues are never the reason these cars die. Rust/tranny usually.

2 Subarus ago, it would throw a weak spark code on #2.
Change that plug, no more code.
I only changed oil every couple years, I finally realized that when the oil
got real old, it was getting past the rings and fouling the plug.

So, check engine light,
Change oil, #2 plug,
keep rolling.

Was starting to rust out, fuel pump died, got a great deal on
an estate clearing car. New owner, is still running it.

Changes arent a waste. Necessary at some level.
On my wife's good car, they are "properly" done,
my current car gets them done on schedule also.

For people that buy new, and never see 100k, 4 or 5 changes
would almost certainly get you there on any good engine.
The last 50k of life is only where it might show.

Turbo, cylinder deactivation engines...I wouldn't think of trying it.

Who'd a ever thought that keeping oil good was a nuisance.

Paul,

I use Havoline VR1 in my 73 Mustang and 70 Dart though both have modern full roller motors. I swap oil/filter every two years with maybe a couple of thousand miles on each. Synthetic, in those vehicles makes no sense as it will be changed every two years. My Porsche, Audi and Tundra go either 10K or, in the case of the Porsche, annually due to warranty. I have a lift so oil changes are esay except with the latest Porsche. Clearly the engineers have been advised... My 2010 Porsche was a piece of cake to maintain on my own. So, sorry, no real data in your case.

Whenever I don’t have time which is every time I need a oil change on one of our commercial vehicles I do the drive in valvoline thing and wait in the vehicle takes 10 minutes they “supposed” put synthetic oil in and change the filter and put a return label at 3k miles cost $50 no problem the last time I did it I asked the guy wearing a stocking cap in 100 degree temps about synthetic oil changes and intervals he said wiping the sweat from his brow 5k for synthetic

I change oil in most everything I own once a year and use synthetics, mostly Mobil 1, occasionally Supertech synthetic, in everything except small engines which gets Supertech SAE 30 and a tractor which get Supertech diesel oil. Using online rebates I can get Mobil 1 from wallyworld cheaper than their Supertech most of the time.

If you read the fine print on the 10K or 20K oils, it will say "x miles or 12 months".....Does not matter if its Amsoil, Mobil 1, whatever.

This leads me to believe that A) They just want to sell you a jug or two of oil once a year even if you don't drive much or B) the additive pack in the oil does break down with time and combustion by products especially if you short trip the vehicle often which I do. I kinda figure its A but am concerned enough that its B that I do what I do. If I drove 50 or 100 highway miles each trip I'd run it to 10k.

2001 cummins with 190,000 mi. never had anything but dino oil but i send a sample in to be analyzed every 10,000 and they keep saying it can go another 2000 mi.
i figure 10,000 is enough for dino oil. but i do wonder what synthetic would go to.

I am still driving a 2003 GMC pickup with the 8.1L gasoline engine. It has always been lubricated with Mobil 1 Synthetic, 5w-30. Currently, there are 234,000 miles on the odometer. My oil change reminder light flickers on at roughly 8900 miles if I let it get that far.

Anyhow, before I started using Mobil 1 I contacted an engineer in their tech department at Exxon Mobil Fuels & Lubricants. He informed me that you could keep the same oil in the pan, changing only the filter and run the oil forever.

Do I believe that sh*te? No, but regular oil change results say that synthetic has been a worthwhile endeavor.

One thing I can tell you from watching it in person- never switch to synthetic on an engine normally lubricated with non- synthetic oil. The synthetic dislodges all the sludge and creates a mud like substance in the oil pan, clogging your pump pickup and starving the engine of oil. Exxon Mobil had multiples lawsuits from aircraft owners in the late 90's over this debacle. And yes, I know an aircraft piston engine is air-cooled and much different from a liquid cooled auto engine.

Thanks for these many posts from your experiences. In trying to do ALL of our vehicle work myself - lifelong approach - I have never had a component, let alone an engine, fail do to lube neglect. 65 years worth of varied rides. The four post lift is a big factor in all of this, but that engine hoist has only yanked one engine - a friend's.

But there is much I do not know about more modern materials and components. So, I ask you folks, and thanks for responding.

I have decided to spin on a new filter and run the oil in the MoHome to about 10k or 11k (upcoming trip) before changing, and to get the kit and send in a sample of this run for testing. Not because I am highly concerned about oil breakdown, but because I am very curious about this aspect. That might lead to longer oil runs in a couple of other "newer" vehicles as well, but never in the real old Chevs. They are babied.

The saying goes once you go synthetic you can’t go back that’s bull schiit

A neighbor has some gizmo in his newish rigs that in theory monitors his oil and warns that it's time to change. Seems to relate to both the calendar and/or mileage and when one or the other is up, he does a change. The calendar section insists on changes even if the rig has not been run.

I'm a greenie and use organic oil that came out of the ground. That being, I don't feel bad about putting it back there when I'm done with it. 200K and counting on the F350 2004 diesel. I do a change when the mood hits me somewhere between 5 and 7K