How to Deal With Chronic Fuel Dilution

[Danh]

Like other DI/TGDI-engined cars, my 2015 CRV suffers from chronic fuel dilution. I gave a long run of premium-only fuel a try to see if it made a difference, but dilution levels remain at around 5%. At the same time, wear metals look just fine.

My UOAs show that fuel dilution is progressive and seemingly irreversible. The mileage limit to keep the 100C cSt of 0w-20 above 6.2 or so seems to be 4,000 highway miles.

Is reduced oil viscosity the primary fuel dilution risk? In the case of a car spec'd for a 20-weight oil, if the oil is changed before it goes below, say, 6.0 cSt, does this pretty much solve any acclerated wear problem? And if a 30 weight oil is used instead (after warranty, of course), would it be similarly safe to run longer and to a higher level of dilution as long as the viscosity stays above the 20 weight minimum?

Thanks for any comments. To me, the unknowns of DI/TGDI durability because of fuel dilution, intake valve deposits, etc. are the biggest issues facing new car owners today as this technology proliferates.

 

[Timo325]

Is there a TB out for these yet? Might be something you can show the dealership if nothing else.

Is reduced oil viscosity the primary fuel dilution risk?

What normally happens when viscosity takes a dump? (That is the risk).

I think going up may help a little with cSt, but I'm only a laymen

 

[Jetronic]

I'd be equally worried about additive concentrations dropping aswell as viscosity.

 

[FordBroncoVWJeta]

The 2015 CRV is a terrible fuel diluter. Buy some of that Pennzoil Gold 0w-20 and SuperTech filter for $20 and change it out every 4-5K.

 

[SatinSilver]

Originally Posted By: Danh
but dilution levels remain at around 5%.


Hi there Daniel,

I went back and looked at the UOA report and it states, greater than 5% for several of the reports. Not sure whey they can't give the exact amount over 5%. Did you do anything differently during the interval that had a normal reading?

UOA

 

[Nissan101]

Step one -use a 10w30 oil (after the warranty period is up)
Step two - Stop thinking about it and enjoy your car

Do you plan to keep the vehicle for a long time?

 

[skyactiv]

What you don't know won't hurt you.
Seriously.
I doubt Honda will have the intake valve deposit issues like the early adopters did such as VW/Audi.
You seem to be a good candidate for a Fumoto valve if you want to change your oil often.

 

[Danh]

Originally Posted By: SatinSilver
Originally Posted By: Danh
but dilution levels remain at around 5%.


Hi there Daniel,

I went back and looked at the UOA report and it states, greater than 5% for several of the reports. Not sure whey they can't give the exact amount over 5%. Did you do anything differently during the interval that had a normal reading?

UOA


Perhaps being a hostage to the port-injected days, Polaris cuts-off at 5.0%, so it could be 6,7,8%, etc. But looking at the viscosity it seems to be close to 5.0%. I have one more data point taken immediately after a trip from Illinois to Colorado using only 91/93 octane fuel: this resulted in 4.4% dilution and a similar drop in viscosity after 2,400 miles.

The only more "normal" reading I've had is on the previously posted group of UOAs. This was also a 91/93 octane fuel run and showed 1.9% dilution after 1,400 miles. I thought this could have been due to higher octane but after my most recent experience I think it was simply working its way to a higher level and would have hit 5% with a little time. All these UOAs were sampled immediately after a long Interstate drive; the 1.9% dilution result was after a long non-Interstate had highway run, so maybe lower speed helped just a bit.

It is funny with Honda DI engines: highway driving almost seems to be a cause rather than a cure. And it's not hard to find other highway driven CRVs and Accords that have similar results.

Thanks for the interest!

 

[Danh]

Originally Posted By: Nissan101
Step one -use a 10w30 oil (after the warranty period is up)
Step two - Stop thinking about it and enjoy your car

Do you plan to keep the vehicle for a long time?


This is probably good advice, though it would be easier to follow if I didn't also have a noticeably increasing crankcase level in winter driving...

My pattern is to keep cars 10 years and 100-120,000 miles. If I were leasing the thing or planned to trade within warranty I wouldn't sweat it.

 

[Danh]

Originally Posted By: FordBroncoVWJeta
The 2015 CRV is a terrible fuel diluter. Buy some of that Pennzoil Gold 0w-20 and SuperTech filter for $20 and change it out every 4-5K.


Can't find the Pennzoil Gold here, but will probably do the early change using an extractor and changing the filter every other OCI as Honda recommends.

But doesn't it bother the heck out of you that Honda is willing to preside very this? To me, it doesn't seem unlikely that Honda made a series of compromises that were good for them (CAFE requirements, fuel economy marketing) at the long-term expense of owners. And as reports trickle in about Honda's new 1.5 GTDI engine this seems like it could be a corporate direction rather than a one-off.

 

[FZ1]

Thanks for your experience with the Premium gas. Was thinking about premium for my 2014 Accord 2.4 DI but concluded than regular is the freshest gas so staying with regular. I think you reached the best solution....extract the diluted oil out.

 

[Eddie]

What do the wear values of Iron, Chrome and Aluminum yield? We're really only interested in wear values and THEN dilution IF there is a problem. We seem to get the sequence backwards sometimes. ed

 

[spasm3]

If i had that level of fuel dilution and no help from the dealer, I'd run a 5w40 hdeo.

 

[Danh]

Originally Posted By: Eddie
What do the wear values of Iron, Chrome and Aluminum yield? We're really only interested in wear values and THEN dilution IF there is a problem. We seem to get the sequence backwards sometimes. ed


Yes, there's the conundrum: wear metals are good. Last UOA, which was admittedly short, 2,400 mile highway run, showed 4ppm of iron, 1 ppm of aluminum and no other wear metals. I guess it depends which side of the UOA argument you're on: if it's that a UOA is to determine the condition of the oil, it's a "fail "; if it's that a UOA determines the condition of the engine, it's a "pass".

Either way, it does suggest nothing horrible is going on inside the engine. But if I followed the oil life monitor and extended the OCI to 12,000 miles I suspect results would be really different.

 

[Eddie]

There is NO oil failure because there is no apparent excess engine wear. I feel we are over reacting with respect to fuel dilution because, at least in this engine, the wear values are very acceptable. Use the factory recommended oil and enjoy your vehicle. Ed

 

[Ducked]

Originally Posted By: Eddie
There is NO oil failure because there is no apparent excess engine wear. I feel we are over reacting with respect to fuel dilution because, at least in this engine, the wear values are very acceptable. Use the factory recommended oil and enjoy your vehicle. Ed


Bearing in mind the caveat that UOA metal values are a rather doubtful measure of wear, and shouldn't therefore really be described as "wear values".

Better suggestions might be:-

"Use the factory recommended oil until it goes out of spec (for viscosity) and enjoy your vehicle." though this requires UOA's to determine when this is likely, or

"Dump the factory recommended oil for something thicker that will stay within spec (for viscosity) longer and enjoy your vehicle."

Both these regimes transfer an unreasonable level of maintenance management responsibility from the manufacturer to the purchaser.

There's also "Dump your vehicle and replace it with something that won't [censored] you off so much." though that's something of a last resort.

 

[Linctex]

Originally Posted By: spasm3
If i had that level of fuel dilution and no help from the dealer, I'd run a 5w40 hdeo.


^ Exactly

 

[zeng]

Originally Posted By: Danh
Yes, there's the conundrum: wear metals are good. Last UOA, which was admittedly short, 2,400 mile highway run, showed 4ppm of iron, 1 ppm of aluminum and no other wear metals. I guess it depends which side of the UOA argument you're on: if it's that a UOA is to determine the condition of the oil, it's a "fail "; if it's that a UOA determines the condition of the engine, it's a "pass".

IMHO,the engine has failed big time as per design parameters like minimum OCI of 10K miles with minimum wear ppm's (like say,maximum 6 ppm of Fe per 10K miles, among others) and maintaining similar exact dipstick oil levels etc.
Wait, OEM knows best right ?
I probably understand why you are'nt following highly revered Manuals Monster here.

 

[SteveSRT8]

Originally Posted By: Eddie
There is NO oil failure because there is no apparent excess engine wear. I feel we are over reacting with respect to fuel dilution because, at least in this engine, the wear values are very acceptable. Use the factory recommended oil and enjoy your vehicle. Ed


Absolutely. While fuel dilution is often lamented here I have yet to see anything attributable to it.

Cars with higher performance tunes usually exhibit it, yet show no damage from it...

 

[Danh]

Originally Posted By: SteveSRT8
Originally Posted By: Eddie
There is NO oil failure because there is no apparent excess engine wear. I feel we are over reacting with respect to fuel dilution because, at least in this engine, the wear values are very acceptable. Use the factory recommended oil and enjoy your vehicle. Ed


Absolutely. While fuel dilution is often lamented here I have yet to see anything attributable to it.

Cars with higher performance tunes usually exhibit it, yet show no damage from it...


Within reasonable limits, this could be a good answer. But it would be really, really helpful if auto manufacturers would say so (Honda certainly won't). And if this is so, would also be helpful if providers of UOAs could move into the DI/TGDI world and not press the panic button when dilution exceeds 2%.