So this is my very first time getting an oil analysis so I barely know what Im looking at. But I recall hearing the engine in my Honda is prone to fuel dilution so I got an oil analysis. Initially the strategy was to use very high grade oil (Amsoil SS) and try to get some life between intervals but if this report is any indication, it seems I should be changing every 4k instead of 8k. Car had 1,500 miles on it when I bought it. At 25k now. 8k miles on this analysis. Oil is Amsoil SS 0W-20.
2021 Civic. 8k Oil Change. Severe fuel dilution.
- Thread starter Reverie
- Start date
What sort of driving do you typically do? mostly city? mostly highway? Was the engine oil fully up to temperature when you grabbed your sample? While the fuel dilution does seem high, everything else seems to be in check. The viscosity is still in the 20 weight range even with the >5% fuel.
Welcome to BITOG 
The Honda 1.5T known for fuel dilution
Use 5w30 next time, and consider filling up with premium rather than regular.
The Honda 1.5T known for fuel dilution
Use 5w30 next time, and consider filling up with premium rather than regular.
The viscosity is still very reasonable for a 0W-20, so there's no obvious need to go up a grade. I'm guessing the Amsoil is fairly thick and doesn't shear much. 5% dilution seems to be normal for these engines.
Fuel dilution will hit a steady state well before 4k miles, so more frequent OCIs won't really help with the viscosity. If you think 7.7 cST is too thin, you can just switch to a 5W-30. Fuel contamination can contribute to other issues like sludge and varnish, especially with low quality fuel, but the oil seems to be in good shape at 8k miles based on the UOA.
Fuel dilution will hit a steady state well before 4k miles, so more frequent OCIs won't really help with the viscosity. If you think 7.7 cST is too thin, you can just switch to a 5W-30. Fuel contamination can contribute to other issues like sludge and varnish, especially with low quality fuel, but the oil seems to be in good shape at 8k miles based on the UOA.
I have to ask why?
Just a note, Oil Analyzers is Polaris Labs and they do not give you the advance "fuel dilution test" without "asking for it". Call back the phone number in the center top of the page and "ask for an interpretation of the analysis". When you talk to the "analysis interpreter" ask for "rerun of the more advanced fuel dilution test". When I was testing my Hyundai turbo when I had bad fuel dilution I had to this every time. Even when I added in the "notes" I wanted the more advanced test, they never did it right off, as I get it, it is an assembly line testing. They will rerun just the fuel dilution test with the more accurate one IF asked. Then post your findings.
Here is the virgin oil analysis for this oil: https://bobistheoilguy.com/forums/threads/amsoil-signature-series-0w-20.366584/#post-6424703
Wear metals are not bad. Viscosity is still in grade. And Oxidation has only increased by 1 over virgin values. I see no reason to lower your OCI with this oil. It looks really good (except for the fuel). I think this oil and your driving pattern is a good combination. If you feel better changing it more often, that won't hurt, but you could continue 8k OCI and everything should be just fine.
Wear metals are not bad. Viscosity is still in grade. And Oxidation has only increased by 1 over virgin values. I see no reason to lower your OCI with this oil. It looks really good (except for the fuel). I think this oil and your driving pattern is a good combination. If you feel better changing it more often, that won't hurt, but you could continue 8k OCI and everything should be just fine.
It looks like they used GC for this sample at >5%, which is what we need to know. What are you suggesting with an "advanced" fuel dilution test?
I would stick to Amsoil as it mitigated the issue that engine is known for. Only thing I would do is go 5W30, and Euro specification, like VW504.00/507.00 I think code is AFE.
I use Mobil1 0w20 EP and never go over 4k, the Honda 1.5T is a dilluter, especially if short tripping, ultimately what you're concerned with is viscosity. There is no magic oil, a good oil changed more frequently is a better alternative to frequent UOA's cost considered. A 5W-30 will stay within acceptable viscosity limits a bit longer, and will work well in your engine. I've owned 5 Hondas with this engine, other than changing oil more frequently, they've been excellent vehicles, good mileage and power. BTY, it's a good idea to change CVT fluid every 30k (spill & fill) using only Honda fluid. Honda CVTs are virtually bullet proof if not abused and changed every 30k. Ignore the MM, it's an algorithm based on average use. Proactive maintenance beats reactive every time.
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Welcome! If you join a dedicated Honda forum, Honda has had this problem for awhile. Back in 19 I was looking at cars.I was studying Honda.The word was owners were having dilution problems and the dealers weren't helping by flat as_lying about it.Honda finally did some strategy will the computers.It seemed that the southern warmer weather states had less issue.If you do short trips and not getting your car really warmed up,your fuel dilution will show like your O.A.I had a 10,000 mile recommended service.I do O.A. ,same company as you.I too had to shorten,I do 5,000 mile,and I now stay good.You are using good oil,kudos for that.But fuel dilution is a very serious engine lubrication issue as it cleans the oil off the cylinder walls.You don't want that.My recommendation is O.A.,shorten drain miles,use a good quality oil,come to your own solution,it's unfortunate that you can't use Amsoil at a extended mileage,that would of bee great.Good luckWelcome to BITOG
The Honda 1.5T known for fuel dilution
Use 5w30 next time, and consider filling up with premium rather than regular.
I would go with a less expensive oil and run 5,000 miles and change the oil and filter. It's cheap insurance and the engine will last longer than you want to drive it.
I think you may be right. They might be doing the advanced test now as standard, or they did not do them with my third party bottle buy.
As others have said, shorten your service intervals. Get a MityVac to make services super fast and easy; swap the filter every 2nd or even 3rd time.
Then run it till the hubcaps fall off.
Then run it till the hubcaps fall off.
Triple_Se7en
$50 Site Donor 2024
I do 3k OCIs with Amsoil Euro 0w30. It's what happens when I keep the vehicles from birth to old age (only owner).
When they finally go to the junkyard, it's dangerous rust that causes the graveyard endings.
If you don't plan on keeping this Honda a long time, use Supertech oils & filters every 5k.
When they finally go to the junkyard, it's dangerous rust that causes the graveyard endings.
If you don't plan on keeping this Honda a long time, use Supertech oils & filters every 5k.
