Oil changes with synthetic

[pasusan]

How often do you change your oil if you use full synthetic oil?

We have a Chevy 6.0 gasoline engine. We are putting Mobil 1 synthetic oil into it and are finding differing requirements. Some say go by miles, others say if you don't put on that many miles change it every year.

We only drive it 2000 to 3000 miles per year. Can we really wait for 7000 miles or more to change it or should it be done every year?

My thinking is why go synthetic if you have to do it every year anyway?

[Cummins12V98]

time2roll wrote:

Cummins12V98 wrote:
Never heard of 80% rule.

Ratings are always under the actual capabilities with a builtin margin.

1/2 ton = rating x 80%
3/4+ = rating / 80% 😉

So by me running at my SAE RAWR of 9,750# I am overloaded?

Maybe some documentation on this 80% rule.

[time2roll]

Cummins12V98 wrote:
Never heard of 80% rule.

Ratings are always under the actual capabilities with a builtin margin.

1/2 ton = rating x 80%
3/4+ = rating / 80% 😉

[Cummins12V98]

dodge guy wrote:
Here is another way of thinking about it!

Why is it when it comes to tow ratings most people say to never push the ratings and to only go 80%! Yet when it comes to maint most people want to push the interval to at or farther than what the manuf recommends.

Just curious!

Never heard of 80% rule.

Ratings are always under the actual capabilities with a builtin margin.

[specta]

Mobile 1 says 15,000 miles and I still only go 5,000. :B

[time2roll]

dodge guy wrote:
Here is another way of thinking about it!

Why is it when it comes to tow ratings most people say to never push the ratings and to only go 80%! Yet when it comes to maint most people want to push the interval to at or farther than what the manuf recommends.

Just curious!

Mobile 1 says 15,000 miles and I still only go 10,000.
And I tow at the max too 😉

[dodge_guy]

Here is another way of thinking about it!

Why is it when it comes to tow ratings most people say to never push the ratings and to only go 80%! Yet when it comes to maint most people want to push the interval to at or farther than what the manuf recommends.

Just curious!

[jerem0621]

BenK wrote:
That CR test with taxis doesn't have one critical cycle of us folks who are not taxis drivers

NY taxis are almost never shut off for more than the time to refuel. In some of those CR reports, there were some who didn't turn off to refuel.

Us non-taxis drivers shut off our engines over might.

That then has moisture drop out vapor to condense inside the engine


Plus the oil film flows off surfaces

To have parts go metal to metal on startup

The why synthetics with better film strength will take longer to flow off

The quality of the filters anti-Drain valve determines how much oil stays in the oil galleries. That helps prevent metal on metal starts

Why more and more oil OEM's are adding molybdenum, which plates metal surfaces

Moly on moly has a VERY low coefficient of friction

Arguable, but many articles report 40%-50%-60% of all wear of an engine

I'm of the opinion of changing engine oil regularly and before the manuals recommendation

Thank you for your opinion on this, BenK.

My new 2022 Silverado cost a huge pile of money and I want this gasoline turbo to last for the next 10 plus years. I don’t want to trade or buy another truck.

This little gem will get fresh oil in the crank case often, coolant changes at 30-50k miles( not sure which yet) due to the variable cooling system (the heads and block can be cooled independently via electronically controlled ball valves.) The transmission fluid will be changed at 50% of the recommended interval, and the other fluids will be changed at 50% recommended intervals.

I need this expensive and impressive (to me) machine to last 10 plus years.

I’ve seen sludge in engines and want to do everything possible to prevent that from happening to my machines.

JMHO.

Thanks!

Jeremiah

[specta]

After reading every post I've decided to change my oil change intervals.
I'm never going to change my oil and filter again.

[BenK]

That CR test with taxis doesn't have one critical cycle of us folks who are not taxis drivers

NY taxis are almost never shut off for more than the time to refuel. In some of those CR reports, there were some who didn't turn off to refuel.

Us non-taxis drivers shut off our engines over might.

That then has moisture drop out vapor to condense inside the engine


Plus the oil film flows off surfaces

To have parts go metal to metal on startup

The why synthetics with better film strength will take longer to flow off

The quality of the filters anti-Drain valve determines how much oil stays in the oil galleries. That helps prevent metal on metal starts

Why more and more oil OEM's are adding molybdenum, which plates metal surfaces

Moly on moly has a VERY low coefficient of friction

Arguable, but many articles report 40%-50%-60% of all wear of an engine

I'm of the opinion of changing engine oil regularly and before the manuals recommendation

[dodge_guy]

ktmrfs wrote:

jerem0621 wrote:

mosseater wrote:
Many years ago, when Hector was still a pup, and folks still believed in silly things like objectivity, Consumer Reports did a pretty thorough test with NY city taxi cabs and oil changes. Sythetic was still a niche market then, but after running taxis for 100K miles on almost all readily available oil brands, they tore them down to inspect and measure. The conclusion was, as long as the oil was changed at the then-standard 3000 miles, it didn't matter if it was mobile one or PepBoys reclaimed oil. Their conclusion was to make sure you changed it. Take that info for what you paid for it.
That said, two things to keep in mind: Your truck may have an "extreme duty" PM schedule because you tow or haul (Ford dealer service manager told me even if you tow occasionally). Point two...I have zero doubt oil now is better than its ever been, so I have confidence that it's lubrication capabilities are up to the 5 or 10K mile task. But....that black stuff in oil, that makes it black? That's dirt. It aint food coloring. Contaminants are so named because they aren't supposed to be there. I have historically changed mine in my former sig pic F 150 because I ran the dog pee out of it when towing. It never went past 4000 miles without a change. For the cost of Motorcraft synthetic blend and a new filter, I'll eat the minimal cost difference to keep sleeping soundly at night with the new truck as well. When my odometer in my 7.3 gas engine in my new F-250 hits about 4000 miles, I'll be crawling under it again with my drain pan. Thats my 4 cents. Y'all can do as you wish. The cost of one oil change per year wouldn't make most of us even blink. I'd love to be in that club.

I Will be doing he exact same with my brand new 2022 Chevy. It's a turbo truck and I will be changing he oil at 4,000 mile intervals or when the OLM hit's 50%, whichever is first.

Oil is cheap, engine work is NOT.

Thanks!

Jeremiah

I've run one duramax 250K miles following the oil life indicator and still only uses 1/2 qt in 10K miles, and I've run 4 other vehicles over the 200K mile mark following mfg recomended oil and change schedule and again, non more than 1/2 qt between changes and Blackstone lab reports always has come back with high TBN and excellent condition on the oil. Change every 4K if you want but all your doing is paying extra $ to the oil companies.

We’re these all diesels? They have always gone longer on oil changes!

[ktmrfs]

jerem0621 wrote:

mosseater wrote:
Many years ago, when Hector was still a pup, and folks still believed in silly things like objectivity, Consumer Reports did a pretty thorough test with NY city taxi cabs and oil changes. Sythetic was still a niche market then, but after running taxis for 100K miles on almost all readily available oil brands, they tore them down to inspect and measure. The conclusion was, as long as the oil was changed at the then-standard 3000 miles, it didn't matter if it was mobile one or PepBoys reclaimed oil. Their conclusion was to make sure you changed it. Take that info for what you paid for it.
That said, two things to keep in mind: Your truck may have an "extreme duty" PM schedule because you tow or haul (Ford dealer service manager told me even if you tow occasionally). Point two...I have zero doubt oil now is better than its ever been, so I have confidence that it's lubrication capabilities are up to the 5 or 10K mile task. But....that black stuff in oil, that makes it black? That's dirt. It aint food coloring. Contaminants are so named because they aren't supposed to be there. I have historically changed mine in my former sig pic F 150 because I ran the dog pee out of it when towing. It never went past 4000 miles without a change. For the cost of Motorcraft synthetic blend and a new filter, I'll eat the minimal cost difference to keep sleeping soundly at night with the new truck as well. When my odometer in my 7.3 gas engine in my new F-250 hits about 4000 miles, I'll be crawling under it again with my drain pan. Thats my 4 cents. Y'all can do as you wish. The cost of one oil change per year wouldn't make most of us even blink. I'd love to be in that club.

I Will be doing he exact same with my brand new 2022 Chevy. It's a turbo truck and I will be changing he oil at 4,000 mile intervals or when the OLM hit's 50%, whichever is first.

Oil is cheap, engine work is NOT.

Thanks!

Jeremiah

I've run one duramax 250K miles following the oil life indicator and still only uses 1/2 qt in 10K miles, and I've run 4 other vehicles over the 200K mile mark following mfg recomended oil and change schedule and again, non more than 1/2 qt between changes and Blackstone lab reports always has come back with high TBN and excellent condition on the oil. Change every 4K if you want but all your doing is paying extra $ to the oil companies.

[Grit_dog]

Lol, where’s that guy that used to post here that he’d change his trans fluid after every big road trip? Now that’s some full tilt, hardcore PM!

[bgiroux]

Sounds like you’ve already made up your mind and are just looking for validation. Oil viscosity begins to reduce the minute it’s manufactured. Here’s a comment from the McNally Institute:
Oil that has not been changed for a long time will begin to gel or solidify in an engine, eventually turning into sludge once it has been exposed to the environment. This will result in oil starvation in crankshafts, bearings, camshafts, and other valve train components if the oil is not able to reach all parts of the engine.
Others have said to go by the manufacturers recommendations, which is also good advice.
At the end of the day you can ignore all these comments and do whatever you want because it’s your vehicle and you are the one who has to drive and repair or replace it. Most of us who replace our oil more frequently due so as preventative maintenance because we want our vehicles to last longer without mechanical issues, but you do you. Good luck.

[Grit_dog]

I know this is rv.net. But can we please quit comparing apples and oranges?
“My oil is black after 1000miles…” No chit Sherlock. Mine is black after 10 miles. It’s a diesel. Not a danm thing to do with the OPs post.
“My engine doesn’t get worked too hard towing….” No chit Sherlock. OPs engine isn’t an industrial power plant designed for 500 hr OCIs and 90% duty cycle…. Or whatever it is….I expect the same folks will give me overtly literal responses because I had the facts wrong. I’m only speaking order of magnitude.

Best part is OP is now extending his OCIs!! Lol. And engine will probably outlast the truck!

[larry_barnhart]

dodge guy wrote:

mosseater wrote:
Many years ago, when Hector was still a pup, and folks still believed in silly things like objectivity, Consumer Reports did a pretty thorough test with NY city taxi cabs and oil changes. Sythetic was still a niche market then, but after running taxis for 100K miles on almost all readily available oil brands, they tore them down to inspect and measure. The conclusion was, as long as the oil was changed at the then-standard 3000 miles, it didn't matter if it was mobile one or PepBoys reclaimed oil. Their conclusion was to make sure you changed it. Take that info for what you paid for it.
That said, two things to keep in mind: Your truck may have an "extreme duty" PM schedule because you tow or haul (Ford dealer service manager told me even if you tow occasionally). Point two...I have zero doubt oil now is better than its ever been, so I have confidence that it's lubrication capabilities are up to the 5 or 10K mile task. But....that black stuff in oil, that makes it black? That's dirt. It aint food coloring. Contaminants are so named because they aren't supposed to be there. I have historically changed mine in my former sig pic F 150 because I ran the dog pee out of it when towing. It never went past 4000 miles without a change. For the cost of Motorcraft synthetic blend and a new filter, I'll eat the minimal cost difference to keep sleeping soundly at night with the new truck as well. When my odometer in my 7.3 gas engine in my new F-250 hits about 4000 miles, I'll be crawling under it again with my drain pan. Thats my 4 cents. Y'all can do as you wish. The cost of one oil change per year wouldn't make most of us even blink. I'd love to be in that club.

I agree, oil gets beat up pretty bad when towing.

Think about all the heat cycles and pressure it’s put through next time you’re climbing I70 in CO or any big climb!
And with that…..how many people change their transmission fluid regularly. I do my trans every 25-30k miles. When I had the Excursion even the rear diff got new fluid at the same intervals.

I also wonder how many people replace their brake fluid? This is a safety item and when towing (stopping) brake fluid gets very hot! Here again I change the fluid at every brake job, about 30-40k miles. On my class A it gets done about every 3 years.

I have changed the brake fluid and steering fluid several times on our 05 rear diff 13 times and allison external filter every year with the trannie 3 times. might be the reason for the truck running awesomr at 114K miles also new coolant 3 times. chevman