Toyota / Lexus A25A-FXS Hybrid engine oil questions

[OilStainedNapkin]

Too much overthinking. M1 (any variety) and any filter at Walmart for 10k intervals would suffice especially for a hybrid. Take a look at some of dnewton’s UOAs to see how far he safely pushed store brand conventional oils to give you confidence. You bought a Lexus/toyota likely because it has a reputation for durability. Rest assured and follow basic maintenance schedules and enjoy your trouble free miles

 

[K24Z7&M20AFXS]

Yeah excepted nobody does the exact same trip in the exact same weather.. right until my current OCI (with Redline oil), i was letting the car run in hybrid mode so the engine was doing a lot of start stop cycles and coolant rarely got over 160°. More so at -30°c during winter.. When i did an oil change, my oil was visibly, severely diluted after 8k km on the odo, so perhaps half that milleage of engine run time as i got enough juice for about 70% of the entire trip..

However, right now, i use the charge mode a lot when i return home to try and force some more heat in that oil. Well see how it's going to look when i do another OC. Right now it's certainly looking good on the dipstick..

 

[K24Z7&M20AFXS]

Thanks to both! The car is brand new still under warranty, so included dealer oil changes will be 0W/16 I suppose. But I'm more worried about engine protection than fuel economy. Yes it's a Hybrid. How much MPG could I lose 2-5mpg?

Between TGMO 0w16 and Pennzoil PU 0w20 in my 2024 Prius Prime, the dufference is soo mute i didn't register it.. it's falling in the margin of error.

Now, in a lab with controlled operating conditions the difference between TGMO 0w16 and TGMO GLV-1 0w8 is something like 0.8%. Figure the difference is the same between 0w16 and 0w20, don't be too scientific and say 1% and you're doing 50mpg... the difference would be something like 0.5mpg..

That's why i never saw a difference.

 

[factorytuned2012]

Newbie here, great forum! I’ve reading a lot about oils and the A25A-FXS engine used on my 23’ Lexus ES 300H. I plan to keep the car for long 12+yr / 100-200k miles; and will adhere to the severe driving conditions OCI of every 5k.

But I still have a few questions for the members of this forum about my specific engine/oil.

1. Is still 0w-16 recommended for this specific engine even if don’t live in colder climate? Winter is rarely below 50-70F and all year mostly between 70-100F. The USA owner manual recommends 0w-16 or 0w-20 for short interval when 0w-16 is not available. But other warmer regions owner's manual recommend 0w-20.
2. Given that I have smelled fuel (faint) on the dipstick; but Blackstone UOA came back as < 0.5% Should I be worried and use 0w-20 to counter dilution? I still plan send a sample to OA on my next change to compare. But I have found that when BSL reports < 0.5% rarely goes above 1-2% when using the GC method.
3. If I drive less than 5k a year, Do I still should change oil at 6 month? Based on a recent BlackStoneLabs study “Motor Oil Age Doesn’t Matter as Much as Mileage: Study”, my guess is that if I only do 5k miles in 2 years, technically the oil should be in similar wear-in condition as 5k in 6 months.
4. Since it’s a hybrid, the engine is off when EV mode is active. Shouldn’t 5k of ODO use represent probable 3-4k of actual engine running/oil usage (less wear)? Maybe Toyota should also include an engine hour usage monitor.
5. Do getting a better oil brand or performance filter will have a meaningful impact in wear in/metals? I think going there is just a case of "diminishing returns" and probably overkill since our engines are not high performance.

Thanks in advance.

Below is more info about my driving style and current UOA:

• Driving Style: Slow acceleration and maximizing mpg; with the occasional hard acceleration for passing and every 1-2 month Italian tune-up (hard acceleration) for cleaning the valves. Currently a low millage driver; probably 5-8k a year. I use Normal or Sport mode for city driving and Eco mode in highway. I'm getting 44-48mpg for a full tack (After Refuel monitoring).
• Trips: Mostly garaged with short trips (8-20miles) 2-3 times a week and the occasional 1.5-2 month long trip of (150-200mi). Although I try to use EV mode when changing car on our driveway the mode is rarely available and the car is on for 1-3 minutes at most. Maybe that's the principal cause of possible oil dilution on my engine.
• Gas: I use top tier gas (Costco 90%+ of the time; or Shell).
• Oil: Lexus dealer included free oil changes for 4 yr at the recommended 10k/12mo interval. I pay for oil changes at 5k/6mo. I suppose they use OEM Toyota oil / filter since they are an authorized exclusive dealer.
• OA: Did my first break-in oil change at 1,300mi (4 months) and a second at 2,694mi (6 month service). I did a UOA for both and could see 50%+ drop in wear-in metals during the same ~1,300mi interval. My next oil change will be at the 12mo service in August and expecting to have no more than 7.5k ODO miles (<5k oil use). Will send samples to BSL & OA to compare, specially the fuel dilution %. Attached my last BSL report.

View attachment 223232

Welcome aboard, 0w20 will do it

 

[K24Z7&M20AFXS]

Yeah excepted nobody does the exact same trip in the exact same weather.. right until my current OCI (with Redline oil), i was letting the car run in hybrid mode so the engine was doing a lot of start stop cycles and coolant rarely got over 160°. More so at -30°c during winter.. When i did an oil change, my oil was visibly, severely diluted after 8k km on the odo, so perhaps half that milleage of engine run time as i got enough juice for about 70% of the entire trip..

However, right now, i use the charge mode a lot when i return home to try and force some more heat in that oil. Well see how it's going to look when i do another OC. Right now it's certainly looking good on the dipstick..

Some sort of results are actually in!

Well compare that with the Redline. With the use of Recharge mode 2 or 3 times a week for my 60km morning commute to work. (..forgot about that one. Wasn't doing it earlier..)

...and compare that to Pennzoil Ultra Platinum and TGMO 0w16 (was looking the same anyway, severely diluted..) WITHOUT Recharge mode.

I put back some TGMO 0w16 i had lying around. I will still use recharge mode and compare next spring.

 

[scubapr]

Thanks to all for the responses. Update: Did my last OC on August 28, 2024 (third overall). It was the free 12mo/10,000mi OCI although the car only had 4,751 miles. Couldn't do the BSL dilution % vs UOA as OA does not service PR. But, BSL did acknowledge some dilution this time.

Comparing all results, I found very interesting all the metals I got out at just half the recommended 10k OCI.

 

[Bkdc]

I was surprised how low the engine temperature was when my 2025 Sienna digital dashboard temperature bar moved to the middle of the bar indicating warm/operating temperature. Oil temperature had only gotten to 115 degrees on my Scangauge 3. With stop and go, I barely get to 160-165F. Sustained highway driving at 70mph, it barely gets to 180 after about an hour unless I'm moving up a hill. I finally hit 190 this week when I got to the top of the Sepulveda pass (Los Angeles 405) at 70mph. The temperature bar was still pegged in the middle. LOL. That bar is pegged to the middle over a pretty wide temperature range. It's probably reflecting coolant temp which does warm up faster and seems to stay warmer than the oil temp in almost all situations.

Engine runs cool, but there is almost no difference between 0W-16 and 0W-20 so I run 0W-20 in the winter and get 37mpg. I'll run 5w-30 in the summer. I'll bet I don't notice the change in MPG.

I do think fuel dilution could be an issue with all the stop starts if you're not making long highway drives on the A25A-FXS. It's only a few bucks more for an extended performance name brand oil with additional additives. Or swap out that oil more frequently with the cheapest spec oil you can find.

 

[kschachn]

Thanks to all for the responses. Update: Did my last OC on August 28, 2024 (third overall). It was the free 12mo/10,000mi OCI although the car only had 4,751 miles. Couldn't do the BSL dilution % vs UOA as OA does not service PR. But, BSL did acknowledge some dilution this time.

Comparing all results, I found very interesting all the metals I got out at just half the recommended 10k OCI.

View attachment 256397

View attachment 256398

Blackstone's fuel estimations are worthless, just FYI. They have been shown to be wildly inaccurate.

 

[scubapr]

Blackstone's fuel estimations are worthless, just FYI. They have been shown to be wildly inaccurate.

Yes, unfortunately OA are not available for my area. Still, although BSL estimations are inaccurate, I suppose getting presence reported probably means a meaningful measurable number on OA. Maybe some "Italian tuneups" between OCI?

 

[kschachn]

Yes, unfortunately OA are not available for my area. Still, although BSL estimations are inaccurate, I suppose getting presence reported probably means a meaningful measurable number on OA. Maybe some "Italian tuneups" between OCI?

No not as seen on here. They aren’t even valid for screening, which the ASTM procedure dictates.

 

[scubapr]

No not as seen on here. They aren’t even valid for screening, which the ASTM procedure dictates.

Good to know. Thanks! I'll try to use a FWD just to get the BSL vs OA comparison on my next OCI.

 

[millerbl00]

I would change the oil at least every 6 months no matter how low the mileage. Toyotas have low tension piston rings like most manufactures and extended oil changes can cause the piston rings to stick over time.

 

[scubapr]

I would change the oil at least every 6 months no matter how low the mileage. Toyotas have low tension piston rings like most manufactures and extended oil changes can cause the piston rings to stick over time.

Thanks! Would you care to explain the why of this piston rings stick due to oil time (6mo) on low millage driving conditions ~5k/yr.

Don't get me wrong, I'm all in for the 6mo/5k OCI mostly since I fall into the "Special Operating Conditions" as per owner's manual recommendation. Also, I don't mind the small $ of oil change compared to the price paid for the car. Still, some people at the dealership (including advisors) look at me like some kind of alien for doing those early Oil Changes at less than ~5K/1yr.

Anyhow, given my own oil analysis results, specially wear-in metals, I'm convinced of these early oil changes. If I were to be a 10k/yr driver, that would mean that at 5k/6mo my car would have had about 622% more wear-in metals dissolved in the oil compared to universal averages for that engine. Dunno if that would only have <1% impact on engine longevity, but I'm happy they are out of the engine for the price I paid.

Now I just want to know, given my low mileage usage (less than 5-6k / yr), if still a 6mo oil change (~3k miles) will be worthy?

 

[millerbl00]

If you are going to keep the car a long time. (Over 50000 miles.) change the oil every 6 months. It's not the miles it's the stop and go and oil not getting to temp. Low tension oil rings mean just that. Very little tension to keep rings open. Short trips contaminate the oil causing varnish causing rings to stick. Especially on Toyotas. Oil is cheap. The dealerships don't want you to change one because of ignorance and 2nd they want to sell repairs and cars sooner.

 

[millerbl00]

Oil reports can't detect varnish.

 

[scubapr]

Thanks! I do plan to keep the car for long; although at my current driving pace the car body will break off, or become a Classic, before I get to the 150k mark.

My next service interval is in Feb 20, 2025 for the 15k/18mo which does not includes oil change. At that point my oil will have only around 2-2.5k of miles usage and 6 months in the engine. Based on the feedback I'll include the oil change and probably use a FWD service to analyze with OA and compare fuel dilution % to BSL.

 

[dkryan]

I would change the oil at least every 6 months no matter how low the mileage. Toyotas have low tension piston rings like most manufactures and extended oil changes can cause the piston rings to stick over time.

Or skip the six month silliness (Oh! We’ve been in the Caribbean for four of the last six months and we drove 1,100 miles during the other two months. It’s time to change the oil!!) Seriously??

If you’re going to waste your money doing that every six months, add up your total cost for an oil change for one year and use the cost from the two OCIs to purchase Amsoil or HPL 0w-20 and change it once per year or at just under 10k miles, whichever comes first.

The piston rings aren’t going to stick with either of those oils and you get high quality wear protection (HTHS of at least 2.7) and CLEANING.

I have your exact engine in a Toyota and I’m quite comfortable with HPL every warranted 10k miles.

If you don’t want to spend the coin on either Amsoil or HPL, I would use 5k mile OCIs, regardless of the time frame, and either Valvoline Restore and Protect 0w-20 or Mobil 1 ESP 0w-30.

I have three more OCIs worth of HPL 0w-20 sitting on the shelf at which point I’ll use the 5w-30 version.

Happy motoring!

 

[millerbl00]

Is a $50 oil change worth the risk?? Will people that say NOT to do an oil change pay for the repair? NO! Change the OIL!
I would stop spending $$$ on oil smaples and just CHANGE THE OIL!

 

[scubapr]

In my case is about $90 every other 6mo service, but I really don't mind the additional oil change cost. I view them as a small investment/insurance given the vehicle cost.

Until warranty, and free yearly oil changes, expires at 4yr/4k I'll keep doing them at the dealership. I still have to be there every 6months for the free maintenance service included. If something goes wrong, it's more easy to get them to respond. I also get "free" snacks, beverages and good while waiting in a comfortable and remote work friendly area. After warranty expires, I'll start doing them myself with Amsoil, HPL or any other high quality available at the time; and I'm sure the cost should be lower.

I don't plan to get oil samples at every change. I just wanted to get a better overview of the "initial oil change" debate and wear-in metals during those first 10k OCI.

 

[scubapr]

It was pointed out on another forum of an UOA for a Rav4 Hybrid (short trips) which has the same A25A-FXS engine as my car. I was really surprised of the high fuel dilution of 5+% and 2.2% with only 4,978 miles and 3,106 miles of oil usage respectively. Didn't expect that from a hybrid which probably had only about 70-80% of that mileage running the ICE.

Apparently a 5-6% dilution will lead to a 25% drop in viscosity. So a 6% could easily be 0W/12 right? If that's the case, keeping a low fuel dilution <2.4% will require 3-4k OCI but not exceeding the Owners Manual 5k recommended for "Severe Operating Conditions"; definitely not the regular 10k OCI. Maybe a few Italian Tune-ups here and there will help drop the %.