Old gearhead here, but very little experience with synthetic motor oil. It was in our MoHome engine when I bought it and have continued with it for an oil and filter change. It is a 2002 Chev 8.1 Vortec/FI setup with 75K miles on the odometer, and almost all running is at 65 to 70 mph on highways. No dirt roads, and mostly clean air. It consumes about 1 qt. of the oil in about 2500 to 3000 miles.

The current oil is at 6k miles, is still a shade of amber and has no fuel smell. It feels quite smooth. My idea is to install a new oil filter and run this oil up to 10k or 11k miles. What do you think? (The synth oil is Costco's finest Kirkland)

I have a hard time finding conventional motor oil these days - you seeing that in your area CCCC ?

I only use full syntyhetic Mobil 1 and have for the past 41 years. I do 6,000 mile oil and filter changes that correspond with my 6,000 mile tire rotations. In the 20 or so trucks, cars, and SUVs that we've had over that time only one engine wasn't still running strong and clean at 200,000, a 1987 GM 2.8L V6 that had very significant ring wear that caused flecks of carbon around 3 to 5mm to build up in the oil. That engine was in an S10 Blazer that had a 4.11 rear end and the low gearing resulted in higher average RPMs, more heat, and more wear. It was a go nearly anywhere SUV, but if you wanted to go anywhere fast, you had to put your foot into it.

I firmly believe that using good oil, a good filter, and changing your oil at regular interval is cheap protection for any engine. I have seen the inside of an engine case that was full of sludge because the owner only added oil, never change the oil or the filter. I change the oil in my other engines, both large and small, annually even if they don't get a lot of use. The engine on my 48kW GENERAC auxillary power unit has a 5.4L V8 and runs for about 30 minutes months or 6 hours per year, not much, but changing the oil and filter doesn't cost much and it gives me peace of mind.

So far, it has not been scarce, but is much more pricey. We have a bunch of 50 year old old Chevy trucks and Corvette, so I gathered up a respectable supply of conventional oil when we lived up in the high remote country - and moved it here. I run conventional Delo in the 2001 Cummins - still available at Costco.

I do need experienced insights on running the synthetic 10k miles with a 5k or so filter change.

I'm not much of a mechanic. My dad taught me that oil is the "lifeblood" of any engine. I change (or have changed) all my oil at half the recommended intervals. This includes the vehicles with synthetic and my outboards.

I have NEVER had an oil related problem with any motor, other than a push mower.

I'm not wealthy, but oil changes are a hell of a lot cheaper than mechanics.

Full synthetic, 10k intervals, change filter every time. Used oil analysis, which is the ONLY way to prove your oil is performing up to spec, is done at every oil change. Cheap insurance.

I started using it in a couple of vehicles after using conventional for years. Usually if I did the changing I'd use Valvoline racing oil on the recommendation of a mechanic. Now it's Mobil 1 or similar.

Vehicle 1: 01 Tacoma, 4 cyl, 4wd. Used a bunch for towing and carrying a decent load for that truck between E WA as far as Fresno CA for a couple of seasons back and forth. As in 500+/- lbs in the bed and cab, and towing a cargo trailer with that much again. Now it's used for hunting trips and going to the feed store and such. Purchased with 110K miles, started using the Mobil 1 on the first oil change after purchase. Originally kept with the old 3-4K mile rule, then talked to others and started going to 5K miles. Then found out about oil analysis, +/- $15 kit from the local Caterpillar dealer. I've installed Fumoto valves in any car I change oil on so it makes sampling really easy. Good filters, Bosch extra mileage type when I can find them. I'm now at 7500 miles between changes and probably going to 10K based on analysis. Truck now has 250k+ miles on it.

Vehicle 2: 2004 Toyota Matrix, 4Cyl now our daily driver. Probably started with the synthetic oil at about 125K, now has 225K miles on it. Same/same with this one, analysis showed "normal" on all parameters last test, so I'll likely go to 10K on this change. Now at about 8K. Gets about 4K before needing 1/2 quart or so.

I also have used a shot of Marvel Mystery Oil with every change, probably going back to the 70s on about every vehicle I've owned. Don't know if it's helped, but apparently with the results I'm getting it hasn't hurt anything either.

C's, if your worried, get a test kit from Caterpillar or some other outfit that will analyze your oil. Another recommendation from a mechanic. If it's good enough for over the road trucking companies, ship owners, and race car outfits, it's good enough for me.

I have switched to the extended life syn oil and filters and run mine for 10,000.

I have an old 2002 Ford Ranger with 219,000 miles which is currently running at 24,000 miles since the last oil change. Pennzoil Platinum High Mileage.

I don't care if it does, but the damn thing just won't die.

I run synthetic to 10,000+. Mobile 1. Last two trucks I sold with 289,000 and 303,000 miles running strong. Currently running Mobile 1 in a 135,000 mile Dodge pu.

I have the dealer change mine every 5000 miles. Believe he uses a blend. Have never had an oil related engine issue. As others have said, cheap insurance to keep it at the right level and performing as oil should.

I use full synthetic oil in my cars. I change the oil and filter in my cars every 10,000 miles. I feel no need to do it any more often than that. They are both 2019 models; engines nowadays are so much better machined than they were when I was younger, and oil is much better now than it was then; and full synthetic takes it to another level. When I bought my 2013 Outback new (it used full synthetic oil as well), I only changed the oil and filter every 10,000 miles in it as well. I traded it in at 150,000 miles; never, ever had a maintenance issue. And I routinely took it on schit that was more like a burro trail instead of a road. Rough-ass country. Ran like a top the entire time I had it.

With even a synthetic change costing little more than a tank of gas these days, there are a lot better things to save money on.

If I “ran” syn oil, that’s exactly what I’d do.

Synthetic oil is at its best @ high mileage intervals and cold temps.

It’s what I put in my daughters car when she lived in Fairbanks and when she and a friend took a cross country trip after college ( collage, for the ‘fire illiterati).

She put ~15K on that trip with a filter change and top off halfway.

For my uses, I mostly “run” cheaper Dino oil and change ~5K because of cooler temps (especially) winter and short trips, thusly not getting to full op temp and to remove condensation.

I bet you’re one of us that’s not got gobs of money, but you’re very wealthy.
😉😉

I have a Chevy truck with A 4.3 V6. I changed the oil at 1K to Mobile1 and I still have it with 187K miles. I change the oil once a year which is about 12K, until I retired. Still going strong, but the body is showing age.

Bought a KIA for my better half in '17, changed the oil three times using Mobile1 and their oil filter/

My Dodge '05 Cummins gets RotellaT 15/40, but I have to do hose changes that will require pulling the oil filter, so for the first time being retired, I have Costco 15/40 oil. Haven't done it yet, but I figure it will still out last me!

10,000 Mobil one and filter changes for me in a Ford 460 in a motor home.
Your plan to change the filter at 6 and everything at 10 or 11,000 sounds like a good one.

I just counted 16 various diesel engines on the farm.
(Jim probably has +20...lol)

Of those, six run on 5w-40 Rotella T6(year-round).

Three F350's and three JD loader tractors.


Cold weather and extended run times are a selling point.

I know they start easier, no idea on engine wear benefits.


Figure roughly 200-300 hours in between changes.





15w-40 Rotella in everything else.

I am very rich!

Just broke.

....................Many varying opinions and experiences on here. Depends I guess on which synthetic oil you plan to use as they vary in quality.........After all of the free oil changes from the dealer expired on my bought new 2015 Ram 1500 Hemi at 36K miles, I converted over to 5w/20 Amsoil Signature Series which is their best. This particular oil is rated at 1 year or 25K miles whichever comes first. I change this oil and change the oil filter every 15K miles using an extended life oil filter. My Hemi uses about 1 quart every 8K miles. Now has nearly 140K miles on it and it still runs like when I drove it off of the showroom floor brand new.....Before converting over and after doing a lot of research comparing oil breakdown tests after x thousands of miles with other 100% synthetic oils, Amsoil is perhaps one of the best synthetic oils, if not the best synthetic oil on the planet.....Yep! It's more expensive, but imo worth it.

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

Like someone else said, Mobile 1 synthetic, oil change every 6,000 miles along with tire rotation.

For what it's worth...
The best thing to come along for engine and oil life was efi.

The excess fuel on starting was hell on cylinder walls and bad for the oil.
The carbon from the too rich mixture of a carb wasn't real friendly either.

Same with diesels.
Electronic controls instantly added huge life expectancies to trucks.
Still remember the adds from Detroit on the Roadway engine with 1,000,000
miles. Tore down for R&D inspection, it was still considered in spec and
useable. At a point a mechanical would have been deep into a rebuilds life.

That kind of life wouldn't come from my earlier posts about not changing oil.
It does serve a purpose.

I use Amzoil in everything newer than 1985.

The oil and filter gets changer at 10,000 in both my truck and the wife's caddy.

In my 2015 it has worked for over 100,000 mi in my truck and it still is going strong.

I had a 1992 Ford Mustang GT.

I ran Valvoline Synetheic (Go Mark Martin).

As the oil aged I’d see a 3-4 milage difference at 5000-6000 miles each change.

I drove from Newport News, VA to Diamond, WV about every other weekend.

Mobil 1 full synthetic and Mobil 1 filter once a year on all my vehicles, regardless of miles. I'm guessing 10 - 12K miles is the most any of them would have in a year.

G23

Great results with Amsoil myself. It is very hard to beat.

Keep reasonably clean oil in your motor and I can’t see it being an issue. Even the cheap Dino stuff has come a long way from the 70’s and 80’s. Changing every 3K or even 5k seems like a waste of time and money.

I change mine about once a year. Top it off when it’s low.

Most oils and fluids have the ability to run much longer than any market filters' ability to keep it clean.

In other words, most motor oil marketed today aren't limited, the filters quit long before oils do.

I can’t recall any vehicle I’ve owned that had sludge or burnt up oil.

Buddy back in high school had a 1979 Cougar with a 351 that was full of oil pudding. Schit was gross. His dad, who he got the car from, always swore by Quaker State. I might avoid that one just because. Lol.

Mobil one and filter at 6000

Way I heard it years ago was to avoid motor oil from the "Pennsylvania" land. Something along the lines of high paraffin content. Maybe one of our resident oil experts can let us know the validity of that. I started using Valvoline a long long long time ago because of that. Before I went to synthetic that is.

You’ll be fine and won’t experience any engine damage.

As all these posts show, run your fave but not incredibly, excessively, rediculously, long periods.

Also, filter changes are more important than oil brand.

I’m still stuck in my NASCAR days….Valvoline Synthetic 10W-35 for the 2005 Ford Ranger.

Mobil 1 0W-20 for the 2014 4Runner and Mobil 1 0W-16 for the 2018 Camry.

Sludge is formed when the oil oxides and forms asphalt compounds. It’s generally due to poor maintenance practices, a faulty PCV system, or just a poor quality oil. The additives absorb moisture, but once they hit their saturation point, the moisture starts to attack the metal causing damage. Sounds like the guy with the Cougar never changed his oil.

Mobil 1 high mileage & a Wix filter every 5,000 miles. Oil is cheap, engines ain't.

1977 wants their lube info back. 😋

Used to tear those engines down, I called em Quaker State motors

Valve train always looked like christmas pretzels double dipped on chocolate

Then, the Havoline motors, they were nice to tear down. Clean all the way down to the keepers.

Paul,

you've seen my 88 4Runner many times at our gatherings... I had it down by your place in March, for that gathering...

I bought it new with 2 minutes on it in Sept of 1987.


I've ran Mobil Diesel truck oil in it most of its life. Filter changes back in the 80s, 90s early 2000s was every 5k, nowadays I run Mobil 1 filters that are 'guaranteed' for 20K miles... I change them at 10K to 12K.

oil changes have been every 20,000 to 25,000 miles...

The truck has the original engine and Trans.... the engine bottom end was overhaul @ 430,000 miles, due to some shop trying to sabotage the engine, to get an engine job out of it...had it done at another shop, but what the first guy did is cut a gasket by the water pump to leak coolant into the oil pan and eat up the bearings...the original head was changed out at 537,000 miles, because it needed a valve job... with 20 to 25K oil changes, the head still had zero sludge on it...I put a New head with bigger valves and it was planed down 20 Thousandths to up the compression...

The truck is parked in the back of my place right now, earlier this week it rolled over 585,000 miles on it.. and the engine...

most of the oil ran in it has been Mobil 5W40 Delvac, or Shell Rotella 5x40...

analysis @ 25,000 miles still comes back that the oil is still good, recommending to run it another 3 or 4K and re submit it... I just keep it at the 25,000

I've had that Truck 33 years next month.

I'd guess, and that is all it is, that it was early PCV systems from the complacent 'big 3" more than most other factors you named. Plus, Quaker State was heavily advertised and super popular back in the day.

I had a truck in a study that the Arkansas Highway Dept. did several years ago, on oil life and change needs. They concluded that it was a variable that depended on how good a job that you air filter did. miles

In my truck I have now I use Mobil 1 full synthetic. Change around 7000 miles. I use a good oil filter.

I use Shell Rotella in my 2004 Dodge diesel and 89 jeep, change every 4000.

Rotella t6 in everything. Did some oil analysis yeas ago at 10k and they said got on to12. Figured that was enough. No oil issues ever. Much cheaper than Dino at 3000 miles. Vatozone used to be the cheapest but prices are going nuts now. Thanks uncle joe and the ho.

I was going 30K miles with filter changes at around 6 or 7 K miles with my old 5.9 Cumins. Periodic oil tests showed all to be good! I still use extended change intervals in my 6.7 Cummins! memtb

Advice is all over the place. Who knows?

My Cummins 5.9 has two factory recommended schedules - A& B.Usual trip is 20-30 RT into town and back. I now average the schedules as that's my driving, at 5K,( and easy to keep track on the odometer) using recommended oil (Valvoline Blue? full synthetic ) and high end filter. I've used Delo Dino at 3K, and Royal Purple at 10 K with new filter and quart at 5. The vehicles are now housed in a heated garage (winter) for the last 5/6 years - which may help with pretty near everything, particularly my wife's happiness....

Doesn't seem to make a lot of difference - as long as you keep it all fresh....and a ood filter, I don't think there is any local service for oil testing, so I don't worry my pretty little head about it. Factory specs are very likely overkill to start with -but the oil testing should tell. Sans that............

2003 Ram 3500, LanceCamper, some towing., coming up on 115K. ( basically parked from 2010 to 2018, run a bit summers only). it ought to be good for 300K, at last I figure - other things are going to go south before then! And have.

Since this is a pre-low-sulfur engine, I use the supplements in the fuel. A bit over minimum in fact- can't hurt!

My wife's Expedition tells you when- I think that is strictly hours. I doubt there is an on-board oil testing system.

The old push in opener with spout paper pensoil can 1/2 full... early 70's ..dad went to add oil to the car and it wouldn't pour ...full of maggots ! ...that was the end of that brand at our place ! Lol !

"The synth oil is Costco's finest Kirkland"

I doubt that it is full synthetic. Costco also sells Mobil 1 which is 100% synthetic. I have been using full synthetic since 1979 in all my vehicles. I put over 300,000 miles on my '78 Chevy pickup and had no engine problems other that worn out valve seals and worn timing chain/gears that I replaced once. I used Mobil 1 and changed the oil/filter every 25,000 miles. A friend bought a '78 Chevy pickup just like mine at the same time and changed his oil/filter every 3000 miles. By the time he drove it 200,000 miles it was smoking, burning oil, the lifters were clattering and it had no power.

when synthetic was gaining acceptance in the early 80s, i noticed a lot of fleet customers were changing to synthetic. when fleets make a change it is only because there is a clear benefit. when i got my next company car...it was a taurus, i decided to experiment. mobil was advertising at the time a 25k change interval. i ran the original oil 5k and put in mobil 1. ran it 25k. changed it and when i turned the car in at 52k, i pulled a valve cover off and it was clean. the car never used oil.

i go by the maint light which now days gets a change at 8 to 10k. works ok so far.

At 30,000 miles I switched to Amsoil 15W-40 Diesel & Marine oil and added an Amsoil bypass filter in my 2005 Dodge Diesel. Since then I have changed the oil and filters every 10,000 miles. I bought it new in Dec. 2005 and so far the only engine maintenance I've done is to replace the water pump, serpentine belts, idler pulleys, radiator hoses and thermostats twice.

An FYI for all the 2004-2009 Dodge diesel owners: I didn't replace the belt tensioner assembly (about $140 at the time) because a friend at the parts store told me that the he had an ACDelco pulley that was the same size as the pulley on the tensioner and I could just change the pulley instead buying a new tensioner assembly. If it's still available the part numbers are: ACD# 38023 and GM# 88926780

I use synthetic oil and change oil and filter around 7,500 miles. I could go longer before oil breakdown, but for me it's about avoiding the contaminants that collect in the oil and get pumped through the engine thousands of times.

Walmart's Syntech, and Costco's Kirland synthetic oils are made by the same manufacturer, and are full synthetic from what I'm told.

Exactly. There is no real world advantage with synthetics unless you want to go 10k+ between changes. I'm not going to do that.

In an article written this month, James L. Roche provides the following (excerpts) about the Kirkland full synthetic motor oil, and compares it with Mobil 1.

"- - - Warren Distribution brand manufactures the Kirkland motor oil, and it is a North American company that is one of the largest blenders of private oil. They are also known for their quality in the oil industry, and they only produce top-class oil for vehicles. - - - -

Kirkland Oil vs Mobil 1
Mobil 1 is undoubtedly a commonly used oil among car owners. But does it mean that Mobil 1 is better than the Kirkland oil? Let’s discuss it in more detail and have a comparison of Kirkland motor oil vs Mobil 1 down below.

Mobil 1 is now recommended by car owners and professionals across the globe. But if you compare it with the Kirkland motor oil, you’d see that these are pretty much identical in terms of quality. But the Mobil 1 is definitely a more costly option. The following points will showcase the similarities of these oil products.

Both are Dexos and API Certified
These both provide great mileage
Enhances the fuel efficiency of the engine
Added additives help to give better wear protection
Fully synthetic design
Trusted manufacturer
Boosts the engine performance

As you saw, these are identical qualities that these oil brands share, but there is a big gap in the pricing and a few of the qualities. Let’s discuss these down below.

While the Kirkland motor oil can’t beat the reputation of the Mobil 1 oil for obvious reasons, it comes much cheaper than it. That truly helps to reduce your overall maintenance cost for your vehicle.

In terms of base stock, both are equally good, but if you’re dealing with a top-class vehicle, it’s better to use a premium quality full synthetic oil in that case.

However, in the comparison for additives, Mobil 1 is the winner. They simply have better additives that help to keep the engine healthier for longer. But Kirkland gives a better fuel economy and better overall performance that you crave.

So, you can already tell that it’s a tie in terms of quality between these two oils. But as Kirkland is a much cheaper alternative compared to the Mobil 1, it’s truly a solid option for you to try out. It’s definitely worth your money and might surprise you with its quality and performance."
FAQ

I drive a ‘19 Hyundai Sonata.

~100 miles a day

At the time. Best mpg for $$$

*I* change mine every 5k miles.

Cheap $40 to blow.

Big truck. Whatever they run, they're doing a 40,000 mile interval. Another company with the same make and model, did 35k the first change then 75k after that, which seemed excessive, but, for their 15000 trucks it musta worked. It looked "bad" on day 1.

I do a full change with synthetic at 10k kms. No troubles. Oil looks clear. No smell.

Warren Oil Mfg

https://bobistheoilguy.com/forums/

The reality is that carbon is going to build up no matter how much you pay for your oil synthetic or not. Change your oil at the same intervals as you would regular oil.

I have read so much on that forum about oil, I realized I will never know it all.

one thing that helps with extension of oil life is that engines are so much cleaner these days. for what it's worth...back in the 'good old days' the change interval to use unless you used white gas was 1000 mi.

there are so few deposits these days that the filters don't do very much work. almost every re ring job i did as a baby mechanic wasn't because the rings wore out, they were sludged up until the rings wouldn't flex to do their job.

CCCC;
Good morning to you sir, I hope the day's looking to be a good one for you folks and all in your world are well.

Way back when on a similar 'Fire discussion, Badger who is a German car repair specialist of some repute said that most engines and motors in good running condition will indicate it's time for an oil change when they start to use more oil than normal. This is going from somewhat faulty memory on my part.

We run full synthetic on everything on the place or in the family other than the lawn mower, so Rotella T6 in the 5.9 Cummins, Pennzoil in an '09 Forester, '05 Corolla, '06 Matrix, Quaker State in an '03 CRV and '04 Mustang and an '87 Cherokee.

As mentioned by many posters, the biggest difference we've noticed is in sub freezing weather, the engine or motor will crank easier and runs smoother after starting.

From the reading and research I've been able to do, a bunch of engine wear takes place in the start up and warm up phase.

We don't run the changes much longer than we used to with the older non-synthetic oils, as I did a couple experiments with the Corolla and Forester and they did start using more oil after going a couple thousand kilometers over the usual interval.

The highest mileage we've had a vehicle go so far was a Jetta with 448,000 km on it when we sold it, so if they keep going we do keep them around.

Hopefully that was useful to you or someone out there.

All the best to you and yours.

Dwayne

shell t4 dino in summer then to t6 syn in winter .... 3500 .... never ever made it to 4000

Running used oil analysis for many years, it tells me that you are very wrong about that.

Spot on JGRaider! Synthetic oil is well worth the money since it reduces friction, heat and resists viscosity thickening about 6 times better

I've ran it for decades.

Spot on JGRaider! Synthetic oil is well worth the money since it reduces friction, heat and resists viscosity thickening about 6 times better

I've ran it for decades.

Running used oil analysis for many years, it tells me that you are very wrong about that.[/quote

So your saying that oil doesn't get "dirty"? If not carbon then what is the material that collects in oil after a number of miles?

I generally use Lucas Oil treatment when I change my oil. If I ran synthetic I would still change it at the same interval which is usually twice a year March and September.

I have over 13,000 hours on my Lincoln Clasdic 11 welding machine and I run Amsoil synthetic diesel oil and drain it once a year. The engine uses no oil run perfectly with no overhaul or other needs.

yeah, but remember... it is made to specs for each customer request.

I still wouldn't hesitate to run Costco's or Walmarts Synthetic oil....

I ran Walmart's Synthetic oil for 20,000 miles with their 20,000 mile filter in a 04 Toyota Camry V 6. She drives mainly around town.
it came back good in a Blackstone Analysis, good TBN still and was recommended to run to 23,000 and re submit it...

for what I drive.... Mobil has been good to me for 35 yrs or more... so I stay a loyal customer to them...Costs $5 more a gallon or so than Walmart Synthetic Oil....at times I do run Walmart Filters, which are good... a lot better than a damn Fram....

I run rotella Syn in the 7.3,Mobil 1 in others, when I had issues with consumption on a Lexus I geeked out and read a lot. Some tests showed syn oil not degrading even at 100k miles. I don’t recall details but an real smart scientist at an Exxon like company brain dumped on an oil forum (yep they exist?!?) He only changed to stay compliant on warranties. I do recall winter freeze was worse than heat. My Bro’s old Org ran all their diesels a year or more of HARD use before changing oil. I do the ‘18 TRD 4Runner every 6-7k like Toyota wants for drivetrain warranty. My others are mostly annual with very little use. Same for the 8-10 small engines. I tend to over service most stuff though and need to keep better logs.

After a year even running 5k miles or less it shows some darker colors but Diesel is at 150k and I mostly just haul with it. Sienna is just over 100k. Not dark like old regular oil/blend that would be black. More the amber color of blend vs. the real translucent syn color. We live in fairly steep terrain so maybe the extra revs up and down too.

The color of the oil has no bearing on whether it's still doing it's job or not.

True, and if the oil is clear, that can be a bad sign. Oil is supposed to suspend carbon particles. If it doesn't , it sticks to engine parts.

My Tahoe hit 300,000 miles before it was stolen.

Due to issues form that event and the fact I have a 100k motor sitting around it will be put back together for more adventures.

Even mobile 1 oil changes are cheap and i do them every 5k cuz it is easy to remember on several vehichles

That is a once a year change on the car and trucks

The ring of truthfulness

We have an 08 Dodge caravan that has 306,000 on it and it has seen nothing but cheap Supertech dyno oil. I have a 2000 Chevrolet Silverado 4x4 that has 275,000 on it and it has had the cheap Walmart oil. I have a 2016 F150 with the 3.5 ecoboost that I have ran nothing but full synthetic in it and my son has an 05 Chevrolet 4x4 with 380,000 miles on it and it has had nothing but Mobil 1 full synthetic in it. As I got older and got the 2016 F150 I started running full synthetic but I’ve had great luck with dinosaur oil. I’ve replaced 3 transmissions in my time but no motors knock on wood. We run our synthetic oil to 5000 miles and I know it will go 7500 to 10,000 miles but after running conventional oil to 3500 miles it takes some getting used to running 10,000 mile oil changes!!