I’m assuming that there is a factual answer to this question but depending on how the thread goes I understand if the mods move it to GD
Using synthoil and a good fluid, you can easily get 10,000 miles per oil change. But even if not at 10,000 miles you should change your oil every 6 months. But many people insist on 5000 miles. In fact, they claim that if you are changing oil every 5000 you don’t need to use the top end synthoils meaning you can even use a blend or conventional and you can use cheap, poor (cough cough Fram) filters. I drive minimum 500 miles per week so if I stick to that schedule I will be at the limit in only 10 weeks.
Ignoring $$$ for a minute, if I were to use top-of-the-line oil (e.g. Pennzoil Platinum Plus) and top filter (e.g. WIX XP) is there any problem changing the oil every 2.5 months / 5000 mi? This may sound like an obvious no but I know some mechanics swear changing the tranny fluid too often is bad.
I’ve heard that it would be counterproductive in some way if you changed the oil daily, something about the oil has closed up molecules that need to open up, or something. I don’t give it much credence, or thought for that matter, but I have heard that.
You can change your oil more frequently, but it would be a “diminishing returns” kind of thing.
Here’s something I’ve wondered about: when you change your oil, I think the oil flow & pressure are abnormally low when you start the vehicle afterwards. (It takes a few seconds for the oil filter to fill up.) If this is accurate, might this be causing additional damage to your engine if you change the oil very, very frequently?
No, it wouldn’t hurt to change your vehicle’s oil more frequently than recommended, but for most people, it’s a waste of time and money UNLESS you drive in such a way or live someplace where your oil is being fouled much quicker than a typical driver.
If you’re worried about it, check it every 1,000 miles and see how dirty it gets, or pull out the oil filter and check it. 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.
I’d say the only real risk is the drain plug seal or threads becoming worn and eventually stripped, especially if the oil pan is aluminum and the plug is steel.
And this is why I do my own oil changes… many places don’t use a torque wrench when tightening the drain bolt. So they overtighten the bolt, because they figure a bolt that’s too tight is better than than bolt that’s too loose. (Either is bad, of course. Which is why a calibrated torque wrench, along with the proper torque spec, should always be used.)
You jest … but this gave me a thought, tangent to the OP in this thread:
Would it be possible to engineer a vehicle that changed its own oil, as it were? I guess you’d have to pre-load a large quantity of fresh oil at some point, and then let the auto-change mechanism do its thing. Maybe it wouldn’t change during trips … but maybe it would/could?
I’m thinking something rotary for the filtering, akin to the working of a revolver. Preload with however many empty filters, set it, and forget it.
As I think about this whole idea … what it would do does is prolong the time between what would be some massive oil changes. What might have to happen first is an engine be designed to use far less oil.
Eh. I doubt any of this is being seriously worked on. Just thinking out loud.
In my case, I’m inexperienced and non-mechanical enough that I think there’d be a higher chance of messing something up if I changed my own oil than if I left it to the professionals.
But with each oil change, whoever actually does it, there’s a small but nonzero chance of something going wrong. So, TOO many oil changes would mean a slightly greater chance of messing something up on your car with no corresponding benefit.
Radial aircraft ICE engines of the WWII and immediately subsequent era often had large offboard oil tanks. Which were used to replenish the engine oil supply inflight on long missions. Between leaking oil & burning oil, these engines could consume gallons per hour in healthy normal operation. One consequence of that is that although the filters weren’t being changed at the same rate, the oil actively circulating in the engine tended to be pretty darn new. IOW, the engine was changing its own oil. It just used a pretty eco-unfriendly method of disposing of the used oil.
In those days most such engines had metallic filter screens, rather than paper filters. Which screens were far more coarse than modern filters. As well complete oil change intervals were short, like 50 to 100 hours of operation. Which would be like changing your car oil about once per complete gas-tank fill.
One issue is that messing with the oil system in any way invites leaks. It also increases the risk of a blowout, which will destroy your engine in a matter of seconds.
I learned this the hard way. I was driving my 1997 GMC Safari van one day, when it started to run rough for some reason. I looked at my dash - no oil pressure! I stopped and popped open the hood. Oil was everywhere.
Here’s what happened: when I bought the van used, the original owner purchased the tow package. Unbeknownst to me, the tow package included an oil cooler. There were two, flexible hoses that connected the oil cooler to the engine. One of the hoses burst, dumping all the oil in a matter of seconds and destroying the engine. Had the van not had the tow package, it would not have had any oil hoses, and I would probably still be driving it. Oil hoses are ticking time bombs on an engine…
No doubt about it. I was thinking of engineering a car engine from scratch for the purpose – not something tacked on to an existing car engine. Or even engineering the overall vehicle to accommodate the auto-change function.
I start getting into pie-in-the-sky thoughts: Can you make the engine out of metals that foul the oil less? Can the oil-filtering be better than in a normal car? Can the overall auto-changing system have fewer seams/seals so that leaking is not an especial risk compared to normal vehicles? And so forth.
EDIT: The lubricant need not be petroleum-based, either.
Thinking of this purely as an engineering question. Money and time are no objects. If we can throw 500 man-years and $500 billion at it, can it be done? And if so how? That “how” is, specifically, the interesting part, not the practicality of the exercise (or lack thereof).
Modern trucks have highly efficient oil filters and that together with improved engine technology allows considerably extended intervals between oil changes.
Thanks to substantial advancements in engine design, after-treatment functionality and oil versatility, many of today’s newer medium- and heavy-duty trucks are capable of oil drain intervals twice or nearly three times as long as trucking’s long accepted 25,000-mile standard.
Perhaps if you used conventional oil it might be a problem to change it very frequently. From what I understand, conventional oil has a wide variety of molecule sizes and the average size matches the weight. Synthetic oil has more consistent molecule sizes where most all molecules will be about the same size. The large molecules in conventional oil may break down and leave you with smaller molecules over time. It may be expected that you’re only in that “large molecule” phase for a short while with normal oil changes. Changing it very frequently may mean you are running with the larger molecules more often. But I don’t know if that would really cause any engine problems or not.
I stopped and popped open the hood. Oil was everywhere. 