# Oil changes and used cars **URL:** \ **Category:** Factual Questions\ **Created:** [January 17, 2025, 1:57pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077 "2025-01-17T13:57:02Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [January 18, 2025, 6:19pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/21 "2025-01-18T18:19:12Z")
> [@Crafter\_Man](#): > > adding too much oil to an engine will damage it. And it’s a red flag for a car with a serious leak, or burning a lot of oil-- the owner gets tired of putting a quart in every week, so they put in a quart and a half. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [January 18, 2025, 6:26pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/22 "2025-01-18T18:26:36Z")
Good point. And this is also why you should stand at the rear of the car after starting the engine. There should be no “smoke” lingering around. (Water mist is normal from the exhaust, especially if it is cold out, but it should quickly become invisible after a few feet. And should become less and less as the engine warms up.) Very generally speaking, a lingering white smoke suggests coolant in one or more of the combustion chambers (blown head gasket), while a blue or grey smoke suggests oil in one or more of the combustion chambers (worn piston rings or bad valve guide seals.) Unless you work on cars, these would normally be considered deal-breakers. But for _me_, if I suspect a blown head gasket and I am still interested in purchasing the vehicle, I will inform the seller of the situation and offer a _significantly_ lower price that what was offered. ---
**Author:** ![Marvin\_the\_Martian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/marvin_the_martian/32/2898_2.png) [@Marvin\_the\_Martian](https://boards.straightdope.com/u/Marvin_the_Martian)\ **Post date:** [January 18, 2025, 10:16pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/23 "2025-01-18T22:16:12Z")
> [@RivkahChaya](#): > > Or he might say he pours the oil out in the woods and the filter in the regular trash-- heh, heh. That’s how my grandfather taught me to do it in the 70s… ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [January 19, 2025, 1:22pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/24 "2025-01-19T13:22:21Z")
> [@Marvin\_the\_Martian](#): > > That’s how my grandfather taught me to do it in the 70s… Well! I, for one, am SHOCKED! Shocked, I tell you! Seriously, what we didn’t know then…people burned trash full of chemicals, plastic bags (albeit, lots of people did still use paper garbage bags) and dry cell batteries. We dumped our cats’ clay litter in the woods. We noticed it didn’t disappear after a rain, so we started burying it about a foot down. In the winter, if the ground froze, we usually put it under the mulch pile, but sometimes we bagged it and tossed it in the trash. People should know better now, and even someone who actually _does_ dump his oil in the woods should _know_ where it’s supposed to go, and lie about taking it there. ---
**Author:** ![FairyChatMom](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fairychatmom/32/21906_2.png) [@FairyChatMom](https://boards.straightdope.com/u/FairyChatMom)\ **Post date:** [January 19, 2025, 1:33pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/25 "2025-01-19T13:33:02Z")
> [@Crafter\_Man](#): > > I will then ask them how they’re able to track the number of miles between oil changes. Every 5K miles - easy to monitor on the odometer. That’s my technique. I used to save all the receipts from work done on my car, but at 13 years and 218K miles, that’s a lot of paper. Since most of the work has been done by the same local shop, I might be able to get a printout, or I could send a buyer to talk to the manager there - he knows me well. Not that I have any intention of selling my car. My goal is 250K miles, if I live that long. I doubt I put 50 miles a week on it any more. ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [January 19, 2025, 1:36pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/26 "2025-01-19T13:36:52Z")
> [@Al128](#): > > That way I ended up with a Honda Fit … and a Volvo V60 station (with the belt change recently done (but otherwise quite a dog of a car)). I bought a Geo Metro (great car, BTW) with 78,000-something miles, a spec for changing the timing belt at 70,000 miles, and a chalk mark on the back of the housing like you would make to calibrate a new timing belt. I asked every master mechanic I knew (and because of the Army, I knew quite a lot). No one could come up with any other reason for the chalk mark than replacing the timing belt. One guy did an external check on the timing for free, and said it was perfect, not like a car with 78,000 miles on the belt. An external check isn’t really diagnostic, but it was just a little more info-- we were all just wondering why someone who was going to sell a car would do expensive maintenance like that. I put another 60,000 miles on it without needing a belt, and then got into an accident. Just a stray bit of info that there are people who really do take care of their cars THAT well. ---
**Author:** ![filmore](https://avatars.discourse-cdn.com/v4/letter/f/7993a0/32.png) [@filmore](https://boards.straightdope.com/u/filmore)\ **Post date:** [January 19, 2025, 1:37pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/27 "2025-01-19T13:37:37Z")
> [@RivkahChaya](#): > > Or he might say he pours the oil out in the woods and the filter in the regular trash-- heh, heh. I see this picture pop up on the internet from time to time. Was this really a recommended way of disposing of motor oil? [![](https://i.imgur.com/uwa0mkk.png) ](https://i.imgur.com/uwa0mkk.png) ---
**Author:** ![RivkahChaya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rivkahchaya/32/8919_2.png) [@RivkahChaya](https://boards.straightdope.com/u/RivkahChaya)\ **Post date:** [January 19, 2025, 1:45pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/28 "2025-01-19T13:45:20Z")
I suppose the idea was to get the oil down under any plants the local fauna used for food (or you did, if you had a garden). And to keep it from killing your lawn, or poisoning your topsoil, in case you wanted it for something else. People doing this probably didn’t have a woods, were therefore suburban, and therefore did not have well water. If you have well water, this is the red carpet to it. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [January 19, 2025, 1:47pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/29 "2025-01-19T13:47:58Z")
Ref @Filmore’s picture from Popular Science … We bought a new suburban house in 1967. One of the first things Dad did was sink a shaft like that adjacent to the garage. Between 3 (later 5) cars, 6 motorcycles, and 10 airplanes (which needed at least _monthly_ oil changes), a lot of oil went down that shaft. I think we stopped using it in the late 1970s. @RivkahChaya: I agree about proper disposal of oil being the right thing to do and also how the idea of pollution really didn’t exist until the late 1960s. At the earliest. But I have a question … > [@RivkahChaya](#): > > We dumped our cats’ clay litter in the woods. We noticed it didn’t disappear after a rain, so we started burying it about a foot down. In the winter, if the ground froze, we usually put it under the mulch pile, but sometimes we bagged it and tossed it in the trash. What is the concern here? You phrase this like another environmentally irresponsible thing to do. Burying feces and dirt in the dirt is bad somehow? I’m not arguing; I’m just utterly ignorant that this might be seen as problematic or why. Or have I misunderstood you completely? ---
**Author:** ![Al128](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/al128/32/16541_2.png) [@Al128](https://boards.straightdope.com/u/Al128)\ **Post date:** [January 19, 2025, 1:51pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/30 "2025-01-19T13:51:32Z")
was this before or after you drove the car down to the river to wash it? [![](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSVL7zf9W-kPy5xo0S1RadPEuADQ5_GpNHHRg&s) ](https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSVL7zf9W-kPy5xo0S1RadPEuADQ5_GpNHHRg&s) ---
**Author:** ![Polarity](https://avatars.discourse-cdn.com/v4/letter/p/7cd45c/32.png) [@Polarity](https://boards.straightdope.com/u/Polarity)\ **Post date:** [January 19, 2025, 2:53pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/31 "2025-01-19T14:53:05Z")
> [@Crafter\_Man](#): > > Do you get under the vehicle to do it? If so, what tools do you use to do that? (If they’re getting under the vehicle, I am looking for words like jack, ramps, etc. If I’m feeling bold I might even ask them to show me these things.) If they claim they pump out the oil from the dipstick tube, I will ask about the pump. I’ve had situations where the seller thought it was odd that I wanted to come into his garage and verify that he owned a jack. Eventually we sat down and went through his old family photo album together. He did have a few pics with some drive on ramps in the background, and I just had to accept it. To this day, I still don’t think that dude was actually changing his oil on time though. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [January 19, 2025, 3:03pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/32 "2025-01-19T15:03:30Z")
> [@filmore](#): > > I see this picture pop up on the internet from time to time. Was this really a recommended way of disposing of motor oil? Not sure. But the article is real. Here is the full page: [![](https://live.staticflickr.com/65535/54275315789_ec4f9dc001_n.jpg) ](https://live.staticflickr.com/65535/54275315789_ec4f9dc001_n.jpg) ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [January 19, 2025, 4:38pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/33 "2025-01-19T16:38:11Z")
I do a lot of oil changes. I dump my old oil into five gallon buckets and take them to a recycling place. Here I am hauling 35 gallons to it. [![](https://live.staticflickr.com/65535/54275240386_c7d7f41060_w.jpg) ](https://live.staticflickr.com/65535/54275240386_c7d7f41060_w.jpg) [![](https://live.staticflickr.com/65535/54275669870_61896f4c63_w.jpg) ](https://live.staticflickr.com/65535/54275669870_61896f4c63_w.jpg) ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [January 19, 2025, 5:45pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/34 "2025-01-19T17:45:26Z")
We have a local guy (lots of farmland around) who has a 55 gallon drum in front of his house and asks for people to dump their old oil in it. He even has a basket for your old oil jugs. ---
**Author:** ![jnglmassiv](https://avatars.discourse-cdn.com/v4/letter/j/f07891/32.png) [@jnglmassiv](https://boards.straightdope.com/u/jnglmassiv)\ **Post date:** [January 19, 2025, 11:57pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/35 "2025-01-19T23:57:40Z")
A distant relative mechanic I know uses waste motor oil for heating his shop/garage at home. I saw it during summer but it looked pretty well done, chimney and ducts all commercial grade. ---
**Author:** ![Lancia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lancia/32/17174_2.png) [@Lancia](https://boards.straightdope.com/u/Lancia)\ **Post date:** [January 20, 2025, 12:36am UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/36 "2025-01-20T00:36:43Z")
For many years my father did his own oil changes and saved the used oil in old milk jugs. He’d use the oil to light burn piles. Usually 2 or 3 each winter. He kept a little 3"x5" spiral notebook in the glove box of each car where he wrote down everything he did to that car. He had a '87 turbo Supra and at one point had to put a new crate engine in it, something he did himself. That one job took up _pages_ in the notebook as he noted, essentially, each component that was adjusted or repaired or replaced. I haven’t done my own oil changes in 20+ years. I don’t own an oil filter wrench (I should, I suppose) and have no idea what size filter my car takes. I don’t know the torque specs for the drain plug but I could find that out easily enough. When I did my own oil changes my process was to tighten the now-clean drain plug down as tight as I could with my fingers and then use a wrench to add ¾ or 1 more turn. I never had a problem with leaks or the plug coming loose. Now I take all my vehicles to a local Valvoline instant oil change place. I have them change the engine and cabin air filters as well. They charge a huge premium to do so but each service they do is reported to Carfax which, as this thread proves, is worth the extra money. Additionally I save each receipt and put it in a “car stuff” binder as well as note it on a Google spreadsheet where I note all the maintenance items performed, which includes oil and filter changes but also unscheduled things like changing the windshield wiper blades (which is needed about every 10K miles) and the time I had replace the gas cap. Naturally the new tires I put on it ~5K miles ago were noted on the spreadsheet while the receipt went in the binder. I also save every gas fill-up receipt. I use a Sharpie to note the car’s total odometer mileage, the mileage since last fill-up, and average MPG for that tank on each receipt. They all live in a little pencil pouch that stays in the driver door map pocket. Organized by date, of course. Why yes, I have OCD. How did you guess? My daily driver is a Kia with only 40k miles on it. I doubt it’ll survive to 200k but I’m damn well going to try. Kia recommendeds oil changes at every 8k miles, I do them at 5k. Like **FCM** noted it just makes things easier. Full synthetic, of course. ---
**Author:** ![DesertDog](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desertdog/32/11503_2.png) [@DesertDog](https://boards.straightdope.com/u/DesertDog)\ **Post date:** [January 20, 2025, 2:24am UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/37 "2025-01-20T02:24:06Z")
> [@RivkahChaya](#): > > On the other hand, someone who says they use an electric or impact wrench, is either lying, or doing something that has likely already damaged the threads. I had to replace the aluminum oil pan in a Honda _twice_ due to cheap oil-change places using an air wrench to tighten. The second time I asked the mechanic if a steel pan was available. None were so I started using him and his torque wrench. The $20 difference was a tenth the price of a new oil pan. ---
**Author:** ![kaylasdad99](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kaylasdad99/32/3398_2.png) [@kaylasdad99](https://boards.straightdope.com/u/kaylasdad99)\ **Post date:** [January 20, 2025, 2:26am UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/38 "2025-01-20T02:26:49Z")
> [@Crafter\_Man](#): > > I own a lot of old cars. I keep a detailed spreadsheet of every maintenance item I do on them. If I were to sell one, I would provide them the spreadsheet. > > (Of course, someone could produce a fake document/fake records. But I doubt very many people would go to the trouble of doing that.) OTOH, lots of people go to the trouble of producing real ones. ---
**Author:** ![Crafter\_Man](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crafter_man/32/458_2.png) [@Crafter\_Man](https://boards.straightdope.com/u/Crafter_Man)\ **Post date:** [January 20, 2025, 2:50am UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/39 "2025-01-20T02:50:33Z")
> [@DesertDog](#): > > I had to replace the aluminum oil pan in a Honda _twice_ due to cheap oil-change places using an air wrench to tighten. I do not recommend taking your car to one of those “quick oil change” places; I’ve heard too many horror stories. An impact wrench shouldn’t be used to remove an oil drain bolt, and (God forbid) should _never_ be used to install a drain bolt. A torque wrench, preferably under calibration control, should be used to tighten it. Some places pump out the oil from the dip stick tube. And I understand why: no one can later accuse them of over or under-torqueing the drain bolt. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [January 21, 2025, 1:28pm UTC](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077/40 "2025-01-21T13:28:36Z")
> [@LSLGuy](#): > > > [@RivkahChaya](#): > > > > We dumped our cats’ clay litter in the woods. We noticed it didn’t disappear after a rain, so we started burying it about a foot down. In the winter, if the ground froze, we usually put it under the mulch pile, but sometimes we bagged it and tossed it in the trash. > > What is the concern here? You phrase this like another environmentally irresponsible thing to do. > > Burying feces and dirt in the dirt is bad somehow? I’m not arguing; I’m just utterly ignorant that this might be seen as problematic or why. Or have I misunderstood you completely? Cat litter isn’t supposed to go in the trash? I had a cranky old friend who one day - overmedicated or just lazy - dumped his kitty litter down the toilet. My other friend the plumber mentioned replacing the toilet after that. “Cement” was one word he used. I had about two gallons of used motor oil back in the good old days when I used to change my own oil. I took it to the town dump and placed it near one of the fires that was burning. I recall seeing a large black cloud going up as I drove back to town. (A couple of years later when I’d moved, I heard the province had made the small town complete change their disposal system. Clay floor to protect ground water, no more burning.) For the last 2 decades I leave it to the dealership to do repairs and maintenance. I have all the papers too, should I ever sell the cars. (Rule of thumb - when car cost more to maintain per year that the equivalent new car payments, time to trade.) I have no record of changing the oil in my Tesla. [Previous page](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077.md?page=1) [Next page](https://boards.straightdope.com/t/oil-changes-and-used-cars/1013077.md?page=3)