Sure. My old pickup truck was like that. It burned enough oil that I never bothered to give it an oil change. I’d change the oil filter every once in a while but I was adding oil to it frequently enough that it effectively changed its own oil.
Probably not what you had in mind though.
I’ll happily plead guilty here. I’ve easily done 200+ oil changes (mostly for myself, but a fair few for friends & family). Never used a torque wrench; never had the smallest torque-related problem. I think it’s a good example of a task where precision simply isn’t important.
This is why I would advise against it.
Same goes for home plumbing. If it ain’t leaking and I look at it sideways: drip, drip, drip…
mmm
One of the best things I ever did to my “new” Subaru (bought in 2012) is install an oil drain valve. With that installed, my oil changes are completely tool-less and super easy. Oil filter is meant to be easy to get to and doesn’t require a wrench to remove (see below). You can reach the oil drain valve without crawling under the car. I’ve never had a vehicle that was so easy to do this maintenance. Subaru deserves two big thumbs up for making oil changes very easy for owners.
Now on the question of too many oil changes, I change mine every 5000 miles. We only drive that car (our only 4-wheeled vehicle) 9000 miles per year so I figure less than twice per year is good. I just did the 95K change. I should say, we used to only drive 9000 miles per year but we now have to travel more for family reasons. But that is 9000 miles between my wife and me. We both commute to work via human powered transmission.
Vehicle wear aside, there are environmental considerations. Petroleum oil is nasty for the environment, even when you dispose of it responsibly, and synthetic oil is a little better, but it’s not a green product. It’s better for the environment mostly by making changes less frequent.
Also, each time you change the oil, you risk some bone-head move, like accidentally stepping in the oil pan, and spilling it all over your gravel driveway, when it will probably eventually sink to the water, and you have well water.
(Bold mine). What might cause this?
I am sure what you’re thinking of is entirely possible.
The reason we have specific, isolated oil changes is that engines were designed in the cheapest way, merely allowing a batch of oil to be drained out and replaced. But we could be continually changing the oil.
There could be an oil tank, or a much bigger oil pan (if there’s room for it down there), and all the oil could be recirculating through it. I think this would be better than swapping out oil on the fly. The average temperature of the oil would be lower and it would degrade more slowly.
You could also add treatment steps to the oil. There’s a particulate filter, and I’m sure grit is a good thing to trap. But I hear that acid builds up in the oil, and that could be extracted with an ion exchange resin cartridge. If there’s water, or carbon soot, or other things, and it’s better not to have them, then you could add specific traps for those too.
If the molecular weight of the oil changes (probably splitting longer chain molecules and decreasing the viscosity or “weight” of the oil), you could monitor this and add back special supplements, such as higher molecular weight oil, so that the mix stays close to the ideal viscosity even though the degradation mechanisms happen at different rates for different molecular sizes. You could even shift this so you wind up with heavier weight oil in the winter and lighter in the summer.
Of course, you could also make this oil easier to swap out when you did have to, even if that’s only every 100,000 miles.
I think this all doesn’t happen because of the economics. But that’s not necessarily in the economic interest of the owner, it’s in the interest of the car maker. For this reason I think it’d be better if you paid more for the car, and the maker assumed responsibility for all maintenance work and materials, to put long service life into the priorities of the maker.
Here are two examples from Ford. Both of these are from the 2019 F-150 owner’s manual.
ETA: Ninja’d by @Bootb. Curses! 
You’re a police department and your cars sit idling whenever they’re parked rather than being shut off.
You live on a big ranch and drive a couple hours a day every day on dusty dirt roads.
You live where the air temperature is over 100F most of every day and night.
etc.
Yes, hot, dry air and dusty dirt roads are tough on your air and oil filter. You need to check them more frequently and change your oil more often than if you live in a more temperate urban or suburban environment.
Sort of covered already, but my first thoughts were:
As in, would it hurt your engine?
It wouldn’t hurt it at all, except that it would put extra wear on your drain plug threads, pan threads, and filter mount threads.
It also wouldn’t help at all either- the 3000 mile oil change as recommended by quick-lube places is dramatically outdated. Modern oil (API SP/ILSAC GF-6A rated) is good for at least 5000 miles, even the run of the mill stuff like Castrol GTX Ultraclean or yellow-bottle Pennzoil. Basically the oil standards have advanced over time such that nowadays, they’re ALL semi-synthetic, and all are good for much longer than the 3000 miles that they used to recommend back in 1984 or thereabouts (API SE/pre-ILSAC rated oil).
Synthetics are great, but really only come into play in the edge conditions where you might have extreme heat or wear, which the vast, vast majority of cars never actually see. They are definitely good for 5000 miles, and some are good for 2x or even 4x that, depending on the oil. Most Euro oils (VW 504.00/ BMW Longlife-04/ MB 229.31 ) qualify, as do some of the US ones(GM Dexos1 Gen2). But not all synthetics meet these specs, and they’re not necessarily good for 10k-20k miles. You have to read the fine print.
If you’re really curious about motor oils, go here and read up. It’s a bunch of oil geeks (!) who discuss the finer (fine as in “angels on the head of a pin”) points of motor oil & cars.
Yeah I’ve been a mechanic for almost 15 years now, in 4 different shops. I’ve never ever seen anyone use a torque wrench for a drain plug. It’s probably similar to expecting a professional cook/chef to measure out every teaspoon of salt.
“A trained person can tell you when it’s time to change your oil, regardless of how long or how many miles since your last oil change.”
A trained person with a tribology lab, perhaps. Otherwise no.
IANA pro mechanic although I’ve rebuilt cars and engines to the last part & wrenched on cars and planes off and on for years.
Agree that in practice torque wrenches are overkill for drain plugs. When they’re being tightened by people with some sense of proportion.
Anybody any good with a wrench has a decent feel for how much oomph is enough based on fastener size, depth, & mission. Which is rarely “All the strength you can muster.”
Plenty of clueless noobs and “Cletus the hulk” types have applied too much torque to small fasteners or to those going into thin or soft material. Or have cross-threaded unnoticed, then use extra oomph to overcome the unexpected, but probably unnoticed, resistance rather than thinking.
Totally not a skilled move. But one that happens every day to somebody’s car.
Anyone who works at KWIK-E-LUBE is a “pro” in the sense they’re’ paid for their work. And that after even 2 weeks on the job will have done more oil changes than most hobbyists will in a lifetime. But that doesn’t mean they know what they’re doing or how their personal standard technique varies from correct procedure.
People given inadequate training before being turned loose to do a task unsupervised often develop bad habits almost immediately and completely unknowingly. Which habits are remarkably resistant to change later.
This thread reminded me of an article I read Eons Ago. I can’t put my finger on it exactly, but … close enough:
Testing Torque by Hand - BMW Motorcycle Owners of America
Whatever issues one might reasonably have with their methodology, the other test I remember reading, years ago, was even more rigorous and arrived at the same basic conclusion: a mechanic’s arm isn’t generally anywhere near as well-calibrated as they think, and definitely not a great substitute for a calibrated TW.
Y’know … FWIW.
ETA: IME, the ‘by feel’ thing can get even wonkier depending on what goes on the threads – nothing, oil, grease, anti-seize, etc.
Related… how comfortable are you relaying on modern car oil life monitoring systems over fixed interval changes?
I’m good with it. My 2010 Dodge 1500 has recommended changes from 5000-8000 miles, I’ve used synthetic since new, it just turned over 193,000 miles without burning any noticeable oil and with zero engine issues over its life.
One potential issue with drain plugs is not replacing or leaving off the crush washer. Drain plugs often have a washer made of soft metal which deforms to create a good seal when tightened. If it’s left off or the old one is reused, then there’s potential to overtighten since the squishy feel of the crush washer isn’t there.
Way back in the day when folks were changing their oil every 500-1500 miles this is exactly what happened. Then the cars would leak a little bit of oil wherever they were parked. Looking at a guys driveway you weren’t sure if he had a petcock issue with his car or an AMF Harley.