Mobil 1 1.9k miles / 2020 48k miles Rav4 - Fuel Dilution

[fueldelusion]

Hello all,

Looking for advice. Here is the only UOA I’ve done on my wife’s 2020 rav 4. We purchased it with around 30k miles on it.

I started to notice an alarming rise in the oil level (smelled fuel-like), decided to dump and get a sample. I estimated an additional 1/4 - 1/2 qt of fuel.

I had the dealership look at it: they couldn’t care less about the UOA, they said it’s normal to get a smell of fuel in the hybrid. I asked questions regarding a potential injector issue or anything of the sort. They were confident if an injector had an issue, it would run rough and/or throw codes. Oh and they thought condensation may have contributed to the rise in oil level — confirming they didn’t care to read the report.

Most if this car’s miles come from 10 mile trips to and from work, mostly highway. The morning drive will have the car leave a ~50 degree Farenheit garage. It’s been relatively cold for this oil’s 2000 miles, we are in the northeast. I didn’t notice nearly as much of a rise, if any, in the summer. It does get longer trips on weekends during the summer months to and from our camp.

Oil was Mobil 1 0w-16 with a Toyota filter. I replaced with M1 5W-30, just to handle the fuel dilution. I will get a UOA and post the results. Interval will depend on how much I see the oil level rise, but planning 3-5k miles.

Looking for recommendations on what to do going forward. We both love this car!

General thoughts:

Before dilution concerns, I was happily running M1 0W-16 on 5-6k intervals.

I’m aware this car in Mexico and Australia specs everything up to 15W-40.

M1 0W-40 is now SP so it’s calcium levels are safe for the DI so I’ve considered that.

Thick oil for winter, thin for summer? (What a world we live in.)

I know all I’ve talked about is M1 but I’m open to anything.

Thanks all in advance, long time lurker.

 

[Pablo]

Over 5%, am I reading that right? Kinda small.

I would document everything, and contact Toyota USA. Definitely see if it repeats.

Have other seen this? (RAV 4's)

 

[fueldelusion]

I should have mentioned this in the original post - it is the hybrid.

Also, I did not expect the high calcium and zinc.

Pablo, it just shows greater than 5 percent. I am mostly concerned with iron and lead levels after such a short run. And the powertrain warranty will be done by mid summer so I havent cared to escalate the dealer’s lack of interest. They also told me Fuel Injectors aren’t part of powertrain, go figure.

 

[Pablo]

Yeah, where did that ZDDP level come from??

Something isn't right. What oil did you run before? M1 same??

 

[ATex7239]

Our Toyota Hybrid dilutes in the winter with short trips too. All good during the warmer months though. Not likely you’ll see any remediation from the dealer. It seems to be the way things are trending these days with direct injection.

Pennzoil Platinum 0W20 (8.8cst @100c) with the same amount of fuel dilution would put you at about the same starting point as M1 0W16 (7.6cst @100c.) Or you could stick with the 5W30 and be way covered. Shorter intervals would be wise in your situation either way.

 

[Danh]

Not sure, but iirc the 2020 RAV4 hybrid is port-injected, so fuel dilution really shouldn’t be much of an issue. And LSPI is only an issue with TGDI engines.

Something isn’t right here. Seems most likely there’s a sample or lab issue. I’ve been there: dealers don’t know/care about UOAs. I’d suggest carrying on and resampling. Another situation where ignorance is bliss…

 

[Ausfahrt]

We have the same vehicle and I agree with ATex. Toyota specs a 10,000 mile OCI and I have been changing it at 5000 just like every other car that I own.

 

[kschachn]

I should have mentioned this in the original post - it is the hybrid.

Also, I did not expect the high calcium and zinc.

Pablo, it just shows greater than 5 percent. I am mostly concerned with iron and lead levels after such a short run. And the powertrain warranty will be done by mid summer so I havent cared to escalate the dealer’s lack of interest. They also told me Fuel Injectiors aren’t part of powertrain, go figure.

I believe 5% is the limit for the ASTM test.

 

[SatinSilver]

My mom's '21 Corolla non-hybrid 1.8 does the same thing. Just don't go over 6 months/5k miles between intervals. Her car only has 9800 miles. Meanwhile, the '12 Camry uses a little bit of oil between intervals.

 

[Ausfahrt]

I believe 5% is the limit for the ASTM test.

No links to fuel dilution threads?

 

[#18FAN]

If easy to do. I’d just start looking at spark plugs see how they are burning

 

[ATex7239]

Not sure, but iirc the 2020 RAV4 hybrid is port-injected, so fuel dilution really shouldn’t be much of an issue. And LSPI is only an issue with TGDI engines.

Something isn’t right here. Seems most likely there’s a sample or lab issue. I’ve been there: dealers don’t know/care about UOAs. I’d suggest carrying on and resampling. Another situation where ignorance is bliss…

I think it is the same dynamic force engine that is in pretty much everything now. If so, it is both port and direct.

 

[joekingcorvette]

I noticed on my Rav4 Hybrid that it seems to take quite a while to warm up. I believe that with the battery running the vehicle off and on around town that the engine probably doesn't get near as hot as a regular non-hybrid engine. I am at only 2,600 miles though and really have not owned it that long since it was purchased right before Christmas and it's a 2024. I think on the interstate it's fine or even driving a lot of miles but the short trips are probably a little harder on the engine.

 

[fueldelusion]

Pablo, yes M1 0W-16 is what was in prior.

Tex, thanks for the input, that pretty much my line of thinking.

#18, good idea with the plugs.

Joe, yes this thing runs very cool in town.

I’m still shocked by what this shows for an addictive pack

Here’s tho ones that stood out to me compared to a 2019 VOA
VOA-UOA
Mg: 794 vs 401
Ca: 1123 vs 1814
P: 644 vs 1121
Zn: 764 vs 1307

Aren’t some of these way outta wack compared to API SP?

VOA: https://bobistheoilguy.com/forums/threads/mobil-1-sae-0w-16-voa.308972/

 

[Pablo]

Making no sense. Call lab.

 

[kschachn]

Pablo, yes M1 0W-16 is what was in prior.

Tex, thanks for the input, that pretty much my line of thinking.

#18, good idea with the plugs.

Joe, yes this thing runs very cool in town.

I’m still shocked by what this shows for an addictive pack

Here’s tho ones that stood out to me compared to a 2019 VOA
VOA-UOA
Mg: 794 vs 401
Ca: 1123 vs 1814
P: 644 vs 1121
Zn: 764 vs 1307

Aren’t some of these way outta wack compared to API SP?

VOA: https://bobistheoilguy.com/forums/threads/mobil-1-sae-0w-16-voa.308972/

Maybe it’s the addictive pack that’s causing your fuel delusion.

 

[fueldelusion]

Finally, someone mentions the pun.

 

[fantastic]

Agree w/ @Pablo & your attention to those elevated additives. Did lab sample wrong one? Double check w/them. Next the viscosity seems to be around a 0w-16 grade so it may be yours but that is quite a lot of additive.

Moving on... The fuel is too high & if it remains like this then you need to move up to higher grade of oil. However, 15w-40 is for diesel & warmer climates normally but it certainly would make me go straight to a 5w-40 Euro oil. Lastly, unfortunately these newer machines seem to be prone to Fuel Dilution above & beyond what has been seen in the past on a regular basis.

 

[fantastic]

Finally, someone mentions the pun.

Prob. someones automatic spell check correction

 

[twX]

With how far off the additive pack is, I'm not entirely convinced they didn't mix up your sample with another, though it does appear to be close to a 0W-16, and the TBN is about what you'd expect from 2k miles, and moly and boron about what should be expected.

The lead is concerning, and while they didn't flag the iron, it's very high for 2k miles.

Most if this car’s miles come from 10 mile trips to and from work, mostly highway. The morning drive will have the car leave a ~50 degree Farenheit garage.

Those starts aren't terribly cold, and your commute is not that short. If this really is a port injection engine, or even dual PFI/GDI, I don't understand why the fuel dilution would be that bad. What is it typically with these engines?

Soot seems to be at 1%, which is very high for 2k miles. 1% soot would be really high even for a diesel engine at 2k miles. My guess is that your engine has an issue causing at least one cylinder to run rich, which is causing the fuel dilution, the soot, and the high wear.