2015 CRV, Mobil1 AFE 0w-20, 2,300 miles

[Danh]

My CRV has a distinct fuel smell in the oil, so I sent a sample off to Blackstone after a 2,300 mile, mostly Interstate run. This took the car from 7,000 to 9,300 miles.

No need to post the Blackstone UOA (as if I knew how to do that anyway), as wear metals were low, as expected.

But, there's a "but". Blackstone calculated fuel dilution as 1% (no biggie) based on a flashpoint of 365 degrees, but the 100c CSt was 6.25. Keeping in mind Blackstone's lower CSt condemnation limit for 0w-20 is 6.00, this is concerning, especially given the low miles in use. As a matter of fact, scouring UOAs here, I couldn't find an 0w-20 of any maker that low, even after many more miles.

So, here are my theories:

1) Lab/reporting error
2) Some low mileage 0w-20 UOAs here show viscosities in the high 6/low 7 range. Is it possible oils shear initially and then thicken with time and resulting oxidation?
3) Lots more fuel in the sample than 1%. But even looking at UOAs here with huge fuel dilution, viscosity didn't suffer as much.
4) A combination of the above.

I'll do a follow-up UOA after a normal OCI, but what do you guys think? Thanks.

As an aside, why do we do this to ourselves? Why can't we just be ignorant yet blissful auto owners? Dealer waiting rooms are full of them.

 

[Wampahoofus]

365 flash with 1% fuel? My gut reaction is that something doesn't jive.

 

[Rand]

6.0 is the lower range for a xw20 oil. Almost no oils are close to that because it can cause engine damage.

AFAIK Blackstone uses a generic method to measure fuel. Its interpreted from flashpoint.

Might want to consider a 0w30 if the low viscosity trend continues.

Those start out about 20% thicker therefore the fuel dilution doesnt make them dangerously thin.

 

[Danh]

Originally Posted By: Wampahoofus
365 flash with 1% fuel? My gut reaction is that something doesn't jive.


I dunno, recent Mobil1 0w-20s from Blackstone as reported here are:

395 degrees = > .5%
345 degrees = 2.0%
385 degrees = trace
355 degrees = .8%

So Blackstone is kind of all over the place, but 365 degrees = 1.0% isn't out of the ordinary.

 

[CarbonSteel]

Originally Posted By: Danh
Originally Posted By: Wampahoofus
365 flash with 1% fuel? My gut reaction is that something doesn't jive.
I dunno, recent Mobil1 0w-20s from Blackstone as reported here are:

395 degrees = > .5%
345 degrees = 2.0%
385 degrees = trace
355 degrees = .8%

So Blackstone is kind of all over the place, but 365 degrees = 1.0% isn't out of the ordinary.
I used Blackstone for a few dozen UOAs, but it is the inconsistencies like this coupled with the $38 UOA (with TBN or TAN) that pushed me to find another lab.

 

[Danh]

Originally Posted By: 2015_PSD
Originally Posted By: Danh
Originally Posted By: Wampahoofus
365 flash with 1% fuel? My gut reaction is that something doesn't jive.
I dunno, recent Mobil1 0w-20s from Blackstone as reported here are:

395 degrees = > .5%
345 degrees = 2.0%
385 degrees = trace
355 degrees = .8%

So Blackstone is kind of all over the place, but 365 degrees = 1.0% isn't out of the ordinary.
I used Blackstone for a few dozen UOAs, but it is the inconsistencies like this coupled with the $38 UOA (with TBN or TAN) that pushed me to find another lab.


Which lab do you use now? I may be shopping, too.

 

[CarbonSteel]

Originally Posted By: Danh
Originally Posted By: 2015_PSD
Originally Posted By: Danh
Originally Posted By: Wampahoofus
365 flash with 1% fuel? My gut reaction is that something doesn't jive.
I dunno, recent Mobil1 0w-20s from Blackstone as reported here are:

395 degrees = > .5%
345 degrees = 2.0%
385 degrees = trace
355 degrees = .8%

So Blackstone is kind of all over the place, but 365 degrees = 1.0% isn't out of the ordinary.
I used Blackstone for a few dozen UOAs, but it is the inconsistencies like this coupled with the $38 UOA (with TBN or TAN) that pushed me to find another lab.


Which lab do you use now? I may be shopping, too.
Polaris/Horizon. I can PM you the details if you would like.

 

[Colt45ws]

Blackstone calculates with 1% for every 20F below the flashpoint "Should be"
That should be value seems to be random. Ive seen anywhere from 355 to 420 and I have no idea what they are basing it off of.
So right there is two assumptions they are making about the oil.
Its no wonder they underreport fuel.
Im betting around 4% is more realistic for this UOA.

If this is a mostly interstate run, you might have a leaking injector or similar issue.

 

[deven]

You should use Mobil 1 0w20 EP if you're worried about fuel dilution and shearing. EP should be more shear stable.

 

[deven]

Delete double post.

 

[bigt61]

How long did you leave the FF in? 7000 miles?

 

[Danh]

Originally Posted By: bigt61
How long did you leave the FF in? 7000 miles?


Factory fill was in for about 5,000 miles/6 months. Between 5 and 7k was winter with lots of short tripping and, with a long road trip coming, I changed again at 7k.

I mentioned the fuel smell in oil issue to my Honda dealer (and fuel smell doesn't seem unusual in the engines) and they arranged, after consulting with Honda's tech staff, a "smell" test with my car next to another 2015 CRV where a technician and I compared the aromas wafting off each one's dipstick. They were the pretty much the same (some fuel, but no notes of leather, cherry or figs), so I really don't think I have a serious fuel dilution issue.

 

[badtlc]

Ignore fuel % as they don't precisely measure that. The flash point and viscosity do agree that you have a fuel dilution problem.

 

[Danh]

Originally Posted By: badtlc
Ignore fuel % as they don't precisely measure that. The flash point and viscosity do agree that you have a fuel dilution problem.


Fuel percentage is by calculated by Blackstone based on flashpoint, so 1% dilution goes with a 365 flashpoint and doesn't indicate more than mild dilution, assuming the flashpoint is correct. And there are lots of 365ish degree flashpoints reported here that have "normal" viscosities. To get to a 6.25 CSt there would have to be massive dilution - I don't think Blackstone's estimate could be that far off.

 

[bigt61]

IMO - the early switch to these high quality full synthetics delays ring break in and contributes to the fuel dilution problem, and maybe even oil usage. I'd run some 5W-20 SN dino for 5000 miles and then switch back to synthetic.

 

[badtlc]

Originally Posted By: Danh
Originally Posted By: badtlc
Ignore fuel % as they don't precisely measure that. The flash point and viscosity do agree that you have a fuel dilution problem.


Fuel percentage is by calculated by Blackstone based on flashpoint, so 1% dilution goes with a 365 flashpoint and doesn't indicate more than mild dilution, assuming the flashpoint is correct. And there are lots of 365ish degree flashpoints reported here that have "normal" viscosities. To get to a 6.25 CSt there would have to be massive dilution - I don't think Blackstone's estimate could be that far off.


You can find UOAs from blackstone where the flashpoint is 365 an the fuel content is all over the place. They are not consistent. Just ignore it. Flashpoint and viscosity is more than enough to make the determination.

 

[Danh]

I queried Blackstone on these results and they very nicely retested the viscosity, yielding a value of 6.88 instead of the 6.25 previously reported. There seem to be two reasons for variations in viscosity readings:

1) the samples we provide aren't completely homogeneous when sampled, so repeated tests can yield slightly different results

2) a human times the flow of a sample through the viscometer, a process than can also introduce variances

A retest of flashpoint wasn't possible as it takes a good part of the sample to complete.

While I'm still a bit puzzled by the results, I feel better with a 6.88 viscosity than a 6.25, even thought there's probably no practical difference. At least I've seen similar viscosities in the BITOG UOA forum before.

In an earlier thread I noted my dealer found a spark plug that was 3/4 of a turn loose, apparently not having been torqued properly at the factory. While it seems unlikely this could con tribute to fuel dilution, I guess you never know. I'll do another UOA during this OCI to see how things progress.

Thanks for the comments.

 

[Wampahoofus]

I can understand how some variance can be built in to the testing process, but to jump from 6.25 to 6.88? Yikes, that's a change of 10%. With tolerances like that I'm not surprised their fuel reporting is all over the board.

 

[Plawan]

Originally Posted By: Danh
My CRV has a distinct fuel smell in the oil, so I sent a sample off to Blackstone after a 2,300 mile, mostly Interstate run. This took the car from 7,000 to 9,300 miles.

No need to post the Blackstone UOA (as if I knew how to do that anyway), as wear metals were low, as expected.

But, there's a "but". Blackstone calculated fuel dilution as 1% (no biggie) based on a flashpoint of 365 degrees, but the 100c CSt was 6.25. Keeping in mind Blackstone's lower CSt condemnation limit for 0w-20 is 6.00, this is concerning, especially given the low miles in use. As a matter of fact, scouring UOAs here, I couldn't find an 0w-20 of any maker that low, even after many more miles.

So, here are my theories:

1) Lab/reporting error
2) Some low mileage 0w-20 UOAs here show viscosities in the high 6/low 7 range. Is it possible oils shear initially and then thicken with time and resulting oxidation?
3) Lots more fuel in the sample than 1%. But even looking at UOAs here with huge fuel dilution, viscosity didn't suffer as much.
4) A combination of the above.

I'll do a follow-up UOA after a normal OCI, but what do you guys think? Thanks.

As an aside, why do we do this to ourselves? Why can't we just be ignorant yet blissful auto owners? Dealer waiting rooms are full of them.

the viscosity could be a typo. Regardless I'd go with a 30 next time. It will only help as it won't thin out as fast

 

[tig1]

Originally Posted By: Plawan
Originally Posted By: Danh
My CRV has a distinct fuel smell in the oil, so I sent a sample off to Blackstone after a 2,300 mile, mostly Interstate run. This took the car from 7,000 to 9,300 miles.

No need to post the Blackstone UOA (as if I knew how to do that anyway), as wear metals were low, as expected.

But, there's a "but". Blackstone calculated fuel dilution as 1% (no biggie) based on a flashpoint of 365 degrees, but the 100c CSt was 6.25. Keeping in mind Blackstone's lower CSt condemnation limit for 0w-20 is 6.00, this is concerning, especially given the low miles in use. As a matter of fact, scouring UOAs here, I couldn't find an 0w-20 of any maker that low, even after many more miles.

So, here are my theories:

1) Lab/reporting error
2) Some low mileage 0w-20 UOAs here show viscosities in the high 6/low 7 range. Is it possible oils shear initially and then thicken with time and resulting oxidation?
3) Lots more fuel in the sample than 1%. But even looking at UOAs here with huge fuel dilution, viscosity didn't suffer as much.
4) A combination of the above.

I'll do a follow-up UOA after a normal OCI, but what do you guys think? Thanks.

As an aside, why do we do this to ourselves? Why can't we just be ignorant yet blissful auto owners? Dealer waiting rooms are full of them.

the viscosity could be a typo. Regardless I'd go with a 30 next time. It will only help as it won't thin out as fast


Why would you advise the OP to use an oil wt not spec'd by Honda? As you can see I use 0-20 with outstanding results as do millions of other folks.