Oil Change Intervals

[Arne2]

On the flip side of the extended mileages, there is still the time interval of 12 (No. Amercica) or 24 months (EU). I don't know about the rest of you, but I don't drive enough miles per year to get to the mileage limit on ANY of my vehicles. All of them get changed by time, once per year.

[blueline]

On the flip side of the extended mileages, there is still the time interval of 12 (No. Amercica) or 24 months (EU). I don't know about the rest of you, but I don't drive enough miles per year to get to the mileage limit on ANY of my vehicles. All of them get changed by time, once per year.

Likewise for me regarding the 12-months occurring before the 10k miles.

But, same as Tom, I like to change oil/filter more often than called for, especially for anything driven hard or in harsh conditions, another situation to take into consideration.

[audi4t]

Since I have too much spare time on my hands I will relate a story about engine wear.

I had a professor in college (mechanical engineering class) who had worked for Rolls Royce Aero Engines.

He told the story about Rolls Royce Merlin Engines (12 cylinder 27 liter 1000 plus hp) used in the Spitfire during
World War II.

To expand capacity, during the war, these engines were also built under license by Packard in the US.

I gather aircraft engines typically get maintenance based on flying hours.

Engines, both UK assembled and US assembled, would undergo maintenance at the same prescribed number of flying hours.

What was seen when the engines were disassembled and inspected was far more wear, "failure" and replacement components needed in the US engines than the UK engines.

Keep in mind the engines were all built to the same specifications and using identical engineering drawings.

The increased wear factor caused concern so the issue was investigated.

The cause was identified as follows:

All components were designed with the requisite engineering tolerances, so as an example the engine block cylinder bore could be plus or minus 10 thou' - similarly a piston could be plus or minus 10 thou'.

The UK Rolls Royce assemblers had an unwritten work practice of selecting components that essentially "blue printed" the engine - so for example they would measure the cylinder bore and select and optimize a piston for that cylinder. This had the effect of minimizing assembly tolerances resulting in less engine wear for given hours of flight,

The US assemblers simply assembled an engine with whatever required components were at hand. No one ever told them to selectively choose components to minimize wear.

Interesting story, at the time, for a budding engineer wet behind the ears

[Tom]

Tom

I don’t think there is a right or wrong answer and obviously oil changes sooner rather than later should be beneficial most of the time.

I’ve experienced a tech not tightening the drain plug after an oil change and oil leaking, but that’s another issue

However, it’s of no benefit for a manufacturer to extend oil change intervals if they aren’t confident the motor and oil are capable.


Turbos do operate at high temps and my 2008 BMW 135i is a straight 6 tru twin turbo not the later biturbo - it now has 73,000 miles on the odo and doesn’t burn a drop of oil.

Long time ago a good friend took his brand new Toyota 4x4 to a quickie lube place (!!) for a quick break-in oil change. They crossed threaded the oil plug and it fell out on the highway, and they ended up paying for a replacement motor! So, yeah, I guess there are risks either way. My brother's F150 calls for new spark plugs at 100k miles. They started to miss around 30k . The going belief is that Ford wanted to promote their car as virtually maintenance-free for the first 100k... (Re BMW maintenance, I had a 2000 323ci that I put 130k on, and then gave to a family member who ran it up to 240k. When he ended up selling it, it still had the factory clutch!)

[GRNEY718]

This topic was revisited on another site, when someone asked about having to change oil at 10K or one year intervals. Two people took offense to the fact that I indicated while I change my oil annually, on my Cayman S (>22k miles, ~ 1.5k/year, zero track days, some short drives) and also send my oil out for analysis. The responses were very unkind, which was odd.

I've been working my own cars since the 80's, primarily because I enjoy it. This includes karts and later race cars, and with an engineering degree to boot, I have a good idea about things. I've owned over 13 cars, never having an oil issue and even was able to get the '71 Motor Trend Car of the year, to over 220k miles (and it is one of the worse cars, of all time!).

I certainly understand why people take their cars in for service to the dealer, or independent shop, and we have some great ones in the area, but I do enjoy working on cars, and have the correct tools. My go to oil is Mobile 1, though I've used others, and there are some great options available. Basically, if you find one you like, and haven't had issues, you're good. I'm not basing anyone who has the work done, and I just like working on cars knowing that others just want to drive them. All good either way.

The oil change on the my 2018 Cayman S, is not the easiest oil change I've ever done on a car. That said, with the right tools, floor check and stands, or lift, it is not bad. I've actually drilled a small hole in the rear floor tray to help the process, covering it up with a rubber grommet. I did have to remove it at the last oil change, as a vacuum valve had gone bad, which was replaced, located up in the tunnel.

I typically change the oil after the break in period. Then, as I do not track or race the car (which requires more frequent oil changes) I change the oil and filter annually or at 5k. I do send the oil out to be analyzed, which helps ensure the engine and oil is good shape, and track any potential changes over time, which does happen. I've been encouraged to go longer on oil changes, but getting under the car once a year, helps me look at other things and potential issues. I also scan the car with my LaunchX431, before and after, checking for codes before starting any work, and checking again and resetting the oil counter when done. I'm not at all saying everyone has to do this, but just expressing what has worked for me.

Tracking and racing your car, requires another set of guidelines, which and requires more frequent fluid and component changes.

[dr bob]

Many people learn (or don't...) from experience, Some their own hard lessons, some from the lessons others have been taught. I can claim both. For good or bad, I'm still of the regular changes and inspections group. Direct results have shown that keeping clean uncontaminated synthetic in the sump does a lot of good when it comes to keeping wear to a manageable level. As much as I trust mechanical filters to remove potential wear particles down to tiny, there are other chemical contaminants and combustion-reaction products that end up in the oil. Component wear ends up in a total area under the contamination curve for run hours. There's a long list of causes of the contamination, but making the assumption that the contributions are consistent means that more regular removal, it looks like more frequent contamination-removal exercises (same as: more frequent oil and filter changes) offer a simple answer to that annoying wear problem.

Two not-Porsche cars in the fleet here get the daily-driver duty especially in winter. Both generate 'smart' oil change recommendations based on operations history including miles driven. They each get driven only a few thousand miles a year now, so fall under the annual service recommendation rather than waiting the several years it would otherwise take for the ECU do decide the service is due. The Mobil 1 that comes out is almost indistinguishable in appearance from what goes in. Seems a bit of a waste. But I have regularly exceeded 250k in service life from other cars treated to this protocol, where visual cam cover, bearing and cylinder inspections along the way have shown very minimal evidence of wear. Still fully visible hone patterns on cylinder walls with zero 'ridge', existing full break-in film still in place on plain bearings, and cam boxes that wipe clean with a lint-free towel are evidence enough for me. There's also the driving gently while engine is not yet up to temperature effect, and an intense PM program for the rest of the moving parts to blame for the results.

Bottom line though is that the regular oil changes and contamination removal, along with the cold-engine throttle discipline, are really really cheap investments in the extended life of the engines. In my own limited experience anyway.

[Tom]

This topic was revisited on another site, when someone asked about having to change oil at 10K or one year intervals. Two people took offense to the fact that I indicated while I change my oil annually, on my Cayman S (>22k miles, ~ 1.5k/year, zero track days, some short drives) and also send my oil out for analysis. The responses were very unkind, which was odd.

I've been working my own cars since the 80's, primarily because I enjoy it. This includes karts and later race cars, and with an engineering degree to boot, I have a good idea about things. I've owned over 13 cars, never having an oil issue and even was able to get the '71 Motor Trend Car of the year, to over 220k miles (and it is one of the worse cars, of all time!).

I certainly understand why people take their cars in for service to the dealer, or independent shop, and we have some great ones in the area, but I do enjoy working on cars, and have the correct tools. My go to oil is Mobile 1, though I've used others, and there are some great options available. Basically, if you find one you like, and haven't had issues, you're good. I'm not basing anyone who has the work done, and I just like working on cars knowing that others just want to drive them. All good either way.

The oil change on the my 2018 Cayman S, is not the easiest oil change I've ever done on a car. That said, with the right tools, floor check and stands, or lift, it is not bad. I've actually drilled a small hole in the rear floor tray to help the process, covering it up with a rubber grommet. I did have to remove it at the last oil change, as a vacuum valve had gone bad, which was replaced, located up in the tunnel.

I typically change the oil after the break in period. Then, as I do not track or race the car (which requires more frequent oil changes) I change the oil and filter annually or at 5k. I do send the oil out to be analyzed, which helps ensure the engine and oil is good shape, and track any potential changes over time, which does happen. I've been encouraged to go longer on oil changes, but getting under the car once a year, helps me look at other things and potential issues. I also scan the car with my LaunchX431, before and after, checking for codes before starting any work, and checking again and resetting the oil counter when done. I'm not at all saying everyone has to do this, but just expressing what has worked for me.

Tracking and racing your car, requires another set of guidelines, which and requires more frequent fluid and component changes.

Sorry about your experience on the other site, but frankly that's exactly why we created Carpokes. I think sometimes people know when they are cutting corners and get defensive when they come across those who don't because it challenges the story they are telling themselves. Imagine getting nasty with someone because they change their oil more often than you do.

[Sportbiker]

I read that same thread about 10k changes which has caused me to reconsider my next change. I was planning 6k miles and pulling a sample but I'm tempted to let it go longer. Part of that reasoning is the difficulty in scoring C4 oil lately thanks to the Hormuz situation. My Pcar is still CPO'd so annually would be as infrequent as it could go but it is a daily driver.

As for the treatment, yeah, not surprised. IMO the ignorant sometimes get real defensive when you challenge their world view with some kind of change. As Tom noted, thus this forum home.