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

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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

If level raised to the point you can see it, then yes. Also testing will show how bad it is, so you kind of know what your engine does.
Its already a big improvement to change oil twice during OLM interval… changing filter is messy
 
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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%.
Again though, the A02 only holds like 6oz of oil. Even if you're at 30% dilution, that's only 2oz of fuel left in the engine from the filter.

And if it's like you say, it's just going to load right back up with fuel... so why not save the money?
 
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Again though, the A02 only holds like 6oz of oil. Even if you're at 30% dilution, that's only 2oz of fuel left in the engine from the filter.

And if it's like you say, it's just going to load right back up with fuel... so why not save the money?
If it were my car it would come down to a risk vs reward thing. Is $5 bucks, or less, worth leaving any fuel in your oil? Especially when you consider it is the sole reason you're changing it in the first place? For me it's not. I'll save $5 somewhere else. Besides, I'm already under the thing. Why not do the job properly?
 
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If it were my car it would come down to a risk vs reward thing. Is $5 bucks, or less, worth leaving any fuel in your oil? Especially when you consider it is the sole reason you're changing it in the first place? For me it's not. I'll save $5 somewhere else. Besides, I'm already under the thing. Why not do the job properly?
For me, if I'm doing 3k miles oil changes to combat severe fuel dilution, I'm not going to bother with the oil filter until the "B" service pops up on my dashboard.

It's going to have a minimal effect on the total fuel dilution overall, you may as well leave it in place. I'd personally be buying Rotella 10W-30 by the bucket.
 
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I run $10 oil filters. One needs to keep balanced approach, its a big step forward dropping diluted oil at half of OLM. Why not do it every 1000 miles? At certain point you getting diminishing returns.
 

wtd

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My fiancé's son has a 2014 F150 with the 5.0 and he uses the OLM to change his oil and it's usually between 9-10K. He drives long distances for work. He uses Motorcraft 5W-20 blend and has around 215,000 miles on the truck and it still runs great.
 
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When I bought a new Mazdaspeed 3 in 2007 the turbo GDI I4 was alleged to have a significant issue with fuel diluting the oil. Numerous self-proclaimed "experts" on the Mazdaspeed forums advised a minimum OCI of 3,000 miles. Multiple UOAs revealed that a 7,500 mile OCI was-if anything-conservative, at least when running Mobil 1 5W-30. I stayed with a 7,500 mile OCI as it lined up with the rest of the car’s maintenance schedule. In any case, the MS3 was still running great at 158,000 miles when I flipped it for the 2 Series.
 
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To answer your question, I would not consider buying any vehicle that I knew had gone with 10K OCI
if I planned on keeping it a long time. That's car abuse in my wheel house. ;)
 
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When I bought a new Mazdaspeed 3 in 2007 the turbo GDI I4 was alleged to have a significant issue with fuel diluting the oil. Numerous self-proclaimed "experts" on the Mazdaspeed forums advised a minimum OCI of 3,000 miles. Multiple UOAs revealed that a 7,500 mile OCI was-if anything-conservative, at least when running Mobil 1 5W-30. I stayed with a 7,500 mile OCI as it lined up with the rest of the car’s maintenance schedule. In any case, the MS3 was still running great at 158,000 miles when I flipped it for the 2 Series.
Well, until you do UOA testing you would not know, and also as our driving patterns change you need to retest. The cost of oil is smaller than UOA, thats why some change oil instead of testing it
 
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