Should we trust the extended oil chg mileage intervals ? Toyota and porsche 10 K miles seems crazy to me..

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Newer synthetic oils and filters can withstand the extended drain intervals. As long as the manufacturer recommends it then I’m cool with it.

the next question becomes do mfgs. recommend the same interval for someone living in Iowa with a 60-mile, no-traffic round trip commute versus someone in Chicago with a 15-minute stop-go commute with the occasional weekend track day.
 
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the next question becomes do mfgs. recommend the same interval for someone living in Iowa with a 60-mile, no-traffic round trip commute versus someone in Chicago with a 15-minute stop-go commute with the occasional weekend track day.
Most manufacturers and manuals have alternate recommendations for what may be considered a severe oci and what not. Also common sense has to be maintained if an individual is automotive savvy otherwise there’s many vehicles left improperly serviced.
 
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The manufacturer set OCI actually being conservative couldn't be possible, it's always set so that you will need a new entire car three days outside of warranty!

Dontch'ya know
It serves them well to be conservative. It takes the owness off them and gets you into their service bays sooner. If they are suggesting 10k intervals I would be comfortable doing 12-13k miles.
 
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So I am in the market for a 996 or 997 porsche 911 manual with some miles..
Also would like to upgrade my family truck / 2001 f350 superduty to a toyota land cruiser or a sequoia . Vintage around 2008 / 2010 with the 5.7 v8.
Both the porsche and toyota / lexus lx470 family have about ten thousand miles for oil changes.. I am kind of worried about buying a 200 k mile used toyota.. or a 140 k used porsche that has had 10 k mile oil changes.
Especially the porsche would have had one oil change per year.
So I am pretty old and was a mechanic a long time ago. 3000 mile to 4000 mile changes were common. The last 20 years I have done 5000 to 6000 mile changes with my trucks and cars.. audi , bmw , vw , ford and porsche.
So I am no expert on modern oils or even modern engine designs. I know direct injection can get more gas in the oil.. my opinion for myself is that oil is cheap and engines are very expensive. The porsche rebuild would cost about 15 k dollars for a 30 to 35 thousand dollar used car..

Do you believe that the ten thousand mile changes protects engines well ?? I can do a mobil 1 oil change even with the porsche large oil volume for 60 or 70 bucks.

I would be interested in your opinions.. when ford and honda and toyota a long time ago went to 5w20 or 0w30 oils I thought it was crazy too thin an oil. But now I just use it and hope the design engineers got it right.
Our 2019 Toyota Highlander went through two engines in 8k miles. If it's a good engine that's built correctly it will be fine if not it will fail.
 
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Once again...
My son had a 2009 328i prior to picking up a 2018 330i xDrive . The car had been run on BMW TPT 5W-30 or BMW TPT 0W-30 since new- with a minimum OCI of 15,000 miles/12 months; here's what it looked like at 108,000 miles:
full-176-33240-e90uh.jpg
 
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GDI engines will not necessarily have discoloration and sludge, the oil gets very thin due to dilution, and its shaving off parts. Need to examine each part for wear, the sludge and staining might not show up.
Classical engines could go longer OCI because fuel dilution was not an issue.
 
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GDI engines will not necessarily have discoloration and sludge, the oil gets very thin due to dilution, and its shaving off parts. Need to examine each part for wear, the sludge and staining might not show up.
Classical engines could go longer OCI because fuel dilution was not an issue.

True. This has been / is a big issue with many Honda engines. And it's one they dance around, because they have not come up with a viable solution as of yet. The biggest cause of the problem is loose fitting piston rings that were deliberately designed into the engine, in order to lower rotational resistance, to increase fuel economy.... Per CAFE requirements.

If you're a short trip city driver this problem is an ever increasing one. Simply because you are not getting the oil up to a high enough temperature long enough, that will allow this fuel contamination to evaporate off. This is especially true in colder climates.

In many Honda engines this fuel dilution has risen the oil level as much as 2 quarts OVER the "FULL" mark on the dipstick, in just a few thousand miles of driving. Causing an already water thin oil to become all but useless as any kind of effective lubricant. Thereby causing the metal shavings you've described.

Not to mention it creates a God awful odor inside the car that is making people sick. Honda is not about to recommend a thicker oil, or implement tighter piston rings, because they would go against CAFE requirements and agreements. The ONLY solution is for the owners of these vehicles going to MUCH MORE frequent oil AND FILTER changes, along with going to a higher viscosity oil. Most won't because they either don't understand the problem at hand. Or else want to listen to people, and in some cases dealers, who suggest the easiest way out is to do nothing. Along with telling them it's "normal".
 
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The ONLY solution is for the owners of these vehicles going to MUCH MORE frequent oil AND FILTER changes, along with going to a higher viscosity oil.
Agree, but not sure its necessary to change filter more frequent. They typically run clean in modern engines, should be able to do 10k miles on a good filter.
 

Astro14

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I’ve had a couple of UOA on a 10,000 mile oil change on my Mercedes.

They looked great. Low wear metals, plenty of TBN left.

If the proper specification oil was used, then 10,000 OCI is just fine.

The 5.7 in the Sequoia is a durable engine, port fuel injected, no dilution issues.

I think you’re fine with both cars.
 
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If its very serious dilution, perhaps.
Fuel dilution of motor oil is bad. If you're changing your oil to rid your crankcase of it, you HAVE TO change the oil filter. Otherwise your are just reintroducing fuel into the crankcase that will pollute the oil you just changed. That just seems like a foolish way to save 5 minutes and $5 dollars.
 
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Fuel dilution of motor oil is bad. If you're changing your oil to rid your crankcase of it, you HAVE TO change the oil filter. Otherwise your are just reintroducing fuel into the crankcase that will pollute the oil you just changed. That just seems like a foolish way to save 5 minutes and $5 dollars.

For 5% dilution, but for 2% I would not change oil filter, its not significunt
 
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For 5% dilution, but for 2% I would not change oil filter, its not significunt

How are you going to know? If you don't change the filter when you change the oil, by the time you get the oil analyzed, you've already contaminated it. Where's the reward here? Saving $5 bucks?

Besides, many of these Honda engines are reading 2 quarts ABOVE "FULL" in just a couple of thousand miles of driving. That's not 2%. More like 30%.
 
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