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One year/10k intervals, really???

WhyNotZoidberg?

WhyNotZoidberg?

Ready to race!
Location
Chi-Town
Car(s)
2017 GTI, 2015 TDI
JerseyDrew77 said:
So who is the preferred choice to do a UOA? Is it Blackstone Labs?
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Blackstone don't test everything (for example even TBN is extra :) )

They especially don't test fuel dilution, they do some estimate of it based on other tests.

I use oaitesting.com (my report above), you could get kits from Amsoil website or dealers, as well as their own website. I also like how you can see trending, historical data & comparative info in your account, separated for each vehicle (eg. my car and my bike).
 
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WhyNotZoidberg?

WhyNotZoidberg?

Ready to race!
Location
Chi-Town
Car(s)
2017 GTI, 2015 TDI
Hoon said:
I've been saying this for 2 years. That's the single reason i stick to 5K intervals.
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It's not that I didn't believe it, I just wanted to see the actual proof.

As an engineer, I was taught the theory, even if it's solid, might get overturned by the actual test :D
 
Sparky589

Sparky589

Drag Racing Champion
Location
San Francisco Bay Area
Hoon said:
I've been saying this for 2 years. That's the single reason i stick to 5K intervals.
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Exactly, there's a reason APR stipulates a 5k oil change interval for their + tune to stay within their warranty.
 
D

DarkArrow

Drag Racing Champion
Location
OC
Car(s)
'18 R
WhyNotZoidberg? said:
Here is a comparison between 2 UOAs, same exact oil, same time of the year (sept'17-apr '18, sep'18-apr'19), only difference is stock tune vs. stg.2.

Since these were both winter intervals, car was not driven hard at all (no track days in MidWest winters, and I don't launch my car or drag race), and I don't do the 'idle your car until it's warm' in the morning (which does increase fuel dilution significantly); I start the engine and 10-15 seconds later I drive away.
I also don't get into boost until the oil is over 80-90deg Celsius.

Moral of the story is tuned cars should get shorter change intervals because of fuel dilution, even though everything else in the UOA shows the oil could easily go beyond 10k miles (wear particles, TBN, oxidation etc.).
I'll keep to 7k miles intervals, unless I see something else in future UOAs that would make me change.

edit: since I wanted to do an apples-to-apples comparo I left out another oil change in between (apr.'18 and sept.'18), which was a different oil, different car usage (summer = track days)
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Is this an OTS tune or a custom tune? Since many OTS tunes are conservative and, therefore, run on the richer side, that could be one reason for a high fuel dilution. If it's an OTS tune, I'm curious if a custom tune would drop it closer to the factory tune dilution level, or if it's a custom tune, I wonder if an OTS tune would make the dilution even worse.

Thanks for the comparison, it's always good to see actual numbers and facts vs opinions.
 
jimlloyd40

jimlloyd40

Autocross Champion
Location
Phoenix
Car(s)
2018 SE DSG
Hoon said:
I've been saying this for 2 years. That's the single reason i stick to 5K intervals.
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I've been changing mine at 4000 miles and when I hit 100,000 miles I'll switch to every 3000 miles. Plus I have an OCC which helps prevent dilution.
 
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lucyfek

Ready to race!
Location
IL USA
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GTI & GSW
Actually, good question toWhyNotZoidberg? would be what his usual trip/commute duration is like. By all accounts, his fuel dilution issue predates the tune. I can only bet that his commute is rather short, mostly city and he's lead foot type. Our winter climate does not help. Indoor or outdoor parking (to make things even worse)?
 
WhyNotZoidberg?

WhyNotZoidberg?

Ready to race!
Location
Chi-Town
Car(s)
2017 GTI, 2015 TDI
DarkArrow said:
Is this an OTS tune or a custom tune? Since many OTS tunes are conservative and, therefore, run on the richer side, that could be one reason for a high fuel dilution. If it's an OTS tune, I'm curious if a custom tune would drop it closer to the factory tune dilution level, or if it's a custom tune, I wonder if an OTS tune would make the dilution even worse.

Thanks for the comparison, it's always good to see actual numbers and facts vs opinions.
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OTS 93oct Eurodyne tune.

As far as my driving habits, I do have a fairly short commute (15miles), but enough to warm up the oil every time to 100C (except for maybe a couple of mornings at below -10F). I am the opposite of "lead foot" ( I don't get into any boost until the oil is well warmed up, and even then I don't think I've ever gone over 10-12psi on the street). Most of my miles (80-90%) are highway miles, and my winter driving is quite different than my summer: in the summer (april-december) I ride my bike most of the time, except for track days, where I drive the shit outta my GTI :D

To the guy saying fuel dilution predates the tune, 2% in 8000 miles is quite normal on a turbo DI engine, perhaps even on the low side.
 
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WhyNotZoidberg?

WhyNotZoidberg?

Ready to race!
Location
Chi-Town
Car(s)
2017 GTI, 2015 TDI
anotero said:
What is this fuel dilution you speak of and why does it happen when tuned?
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Tunes add boost, and in turn add rich fueling to prevent knock from leaning out.
Rich mixture means extra fuel doesn't get burned and ends up in the sump.
 
Hoon

Hoon

Autocross Champion
Location
Rhode Island
DarkArrow said:
Is this an OTS tune or a custom tune? Since many OTS tunes are conservative and, therefore, run on the richer side, that could be one reason for a high fuel dilution. If it's an OTS tune, I'm curious if a custom tune would drop it closer to the factory tune dilution level, or if it's a custom tune, I wonder if an OTS tune would make the dilution even worse.

Thanks for the comparison, it's always good to see actual numbers and facts vs opinions.
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I've had Oil Analyzers test mine on both OTS and pro-tune. Pro-tune was slightly better but not significantly.

You can't use Blackstone for this BTW, their method is useless.

lucyfek said:
Actually, good question toWhyNotZoidberg? would be what his usual trip/commute duration is like. By all accounts, his fuel dilution issue predates the tune. I can only bet that his commute is rather short, mostly city and he's lead foot type. Our winter climate does not help. Indoor or outdoor parking (to make things even worse)?
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I do almost zero short trip driving. It's very rare I drive for less than 30 minutes, and oil always reaches 215-225 degrees. Even with this I still had close to 2% fuel dilution in 4500 miles. Not nearly as bad as his, but still noteworthy. I'm also on 28-29psi boost and have a heavy foot.
 
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lucyfek

Ready to race!
Location
IL USA
Car(s)
GTI & GSW
Hoon said:
I do almost zero short trip driving. It's very rare I drive for less than 30 minutes, and oil always reaches 215-225 degrees. Even with this I still had close to 2% fuel dilution in 4500 miles. Not nearly as bad as his, but still noteworthy. I'm also on 28-29psi boost and have a heavy foot.
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Interesting. I've never cared to test oil on any of my cars and used to think that 35 mile commute would evaporate any blow by but your results seem to question this assumption (though I don't push mine to 29psi). OTOH, my 18 year old Focus has been subjected to 7.5-10k oil change intervals (0w-30 and 0w-20, pretty much since new) and I don't expect the engine failing before rust gets it (arguably simple and "field" serviceable design, I'm not event going to do 2nd timing belt change at 240k as it can be done after the failure, if I cared to at that point).
 
Hoon

Hoon

Autocross Champion
Location
Rhode Island
lucyfek said:
Interesting. I've never cared to test oil on any of my cars and used to think that 35 mile commute would evaporate any blow by but your results seem to question this assumption (though I don't push mine to 29psi). OTOH, my 18 year old Focus has been subjected to 7.5-10k oil change intervals (0w-30 and 0w-20, pretty much since new) and I don't expect the engine failing before rust gets it (arguably simple and "field" serviceable design, I'm not event going to do 2nd timing belt change at 240k as it can be done after the failure, if I cared to at that point).
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The focus isn't DI so no worries.

The fuel dilution is a DI issue, especially with the increased fuel and airflow of tuned cars.
 
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