Lake Speed Jr. Tribologist discusses 0W8 motor oil

[K24Z7&M20AFXS]

I am curious as to why a 2023 Corolla recommends 0w-8 whereas my son's 2023 Prius recommends 0w-16. Don't they both employ the same 2 liter engine? Wouldn't one expect a hybrid drive train to be easier on the oil vs a traditional ICE drive train?

Well i think the hybrids are actually harder on their oils. Most hybrids are dealing with a ton of start stop cycles, gas and water dilution due to oil not reaching it's operating temperature, etc.. As a fact, the Priuses were the first car that i owned that were shown to absolutely destroy their oils. Did my commute change between the Civic and the Prius? Nop! Yet, at the end of an OCI, the Civic's oil is always nice and black and the Priuses oil always were very reeking of gas and a color that was looking as grey and tan/brownish paints being mixed together... to prevent that, i might have to use it's Charge mode a lot. It will force the engine to stay on to recharge the battery, will more or less negate the fuel econ that it's giving me and also be a lot nicer for the engine... pick your poison..

Mine's a 2024 Prime btw!

P.S. same engine family (M20A) but not the same sub-family as the Corolla uses a M20A-FKS (13:1Cr, probably some trick Otto to Atkinson cycle a-la-Skyactiv) and Priuses uses a M20A-FXS (Atkinson Cycle and 14:1Cr)

 

[K24Z7&M20AFXS]

Why one would perform a "fun" test with an expensive vehicle is a bit beyond me. Especially when there is no way that person could ever make a valid analysis of their experiment.

You won't have to convince me. I think the same. I was telling ZeeO6 that i would buy a nice used Civic to experiment on if i had loads of cash. But honestly, if you tell the dude "Don't do that!! 0w5 is going to harm the engine!" do you think he will listen? Nah..! Might as well hop in for the ride..

 

[K24Z7&M20AFXS]

I'd also imagine the hybrid doesn't need a 0w8 to hit MPG goals. Where the non hybrid needs every advantage it can get.

I would be inclined to think that if they can get 0.5% better fuel economy in a Prius with 0w8 without causing problems, they would be all over it. Remember CAFE means Corporate AVERAGE Fuel Economy.

 

[CarlB]

I would be inclined to think that if they can get 0.5% better fuel economy in a Prius with 0w8 without causing problems, they would be all over it. Remember CAFE means Corporate AVERAGE Fuel Economy.

Once you hit the goal, there isn't a prize for more.

 

[Astro_Guy]

You’re wondering if a 16-grade oil would be fine in a vehicle where an 8-grade is recommended?

Sorry but that was a brain fart. I was questioning the opposite. There was a link to a UOA of 0w-8 HPL Premium Plus earlier in this thread [?] if I recall and it showed that oil thickening over time. I was rather wondering if starting with a 0w-8 that might thicken up along the way would be a good substitute for a 0w-16. I have the HPL Premium Plus 0w-16 ready to go for this vehicle but I just stopped to ponder this.

Many good replies to the hybrid vs. standard ICE question. The major use case for this vehicle does suggest a good possibility of fuel dilution. We'll see with the first UOA and go from there.

 

[K24Z7&M20AFXS]

Sorry but that was a brain fart. I was questioning the opposite. There was a link to a UOA of 0w-8 HPL Premium Plus earlier in this thread [?] if I recall and it showed that oil thickening over time. I was rather wondering if starting with a 0w-8 that might thicken up along the way would be a good substitute for a 0w-16. I have the HPL Premium Plus 0w-16 ready to go for this vehicle but I just stopped to ponder this.

Many good replies to the hybrid vs. standard ICE question. The major use case for this vehicle does suggest a good possibility of fuel dilution. We'll see with the first UOA and go from there.

Well my own Prime does show fuel dilution, both visually and olfactory, if i don't use Charge mode (until proven otherwise next oil change anyway..). Look at that..

With Charge mode on 2 or 3 days a week (0w20 Redline HP oil used)

And that was without Charge mode at all... (sarcasm/on)..this is a hybrid and so i shall save the planet after all.. (sacrasm/off) (also, 0w20 Pennzoil Ultra Platinum was used, TGMO looked the same..)

This one just reeked of gas.. didn't had an analysis done, would have been lovely..

 

[nthach]

Well i think the hybrids are actually harder on their oils. Most hybrids are dealing with a ton of start stop cycles, gas and water dilution due to oil not reaching it's operating temperature, etc.. As a fact, the Priuses were the first car that i owned that were shown to absolutely destroy their oils. Did my commute change between the Civic and the Prius? Nop! Yet, at the end of an OCI, the Civic's oil is always nice and black and the Priuses oil always were very reeking of gas and a color that was looking as grey and tan/brownish paints being mixed together... to prevent that, i might have to use it's Charge mode a lot. It will force the engine to stay on to recharge the battery, will more or less negate the fuel econ that it's giving me and also be a lot nicer for the engine... pick your poison..

Mine's a 2024 Prime btw!

P.S. same engine family (M20A) but not the same sub-family as the Corolla uses a M20A-FKS (13:1Cr, probably some trick Otto to Atkinson cycle a-la-Skyactiv) and Priuses uses a M20A-FXS (Atkinson Cycle and 14:1Cr)

There’s 3 Toyota hybrids here - 09 Gen 2 Prius with 222K on it(mine), an 19 RXh with 145K and a 25 Camry with 26K(parents). The RX saw Uber use, which is now the Camry’s domain. I’ll say this, the oil from the Prius, even HPL looks like it saw better days, but oddly enough the RX’s oil comes out either a golden brown or a moderately dark brown. The jury’s out on the Camry but the times I did an OCI on it, it was dark. There’s TGMO 0W-8 in the Camry, but I use M1 0W-16 since it’s all WM has. I can smell a wiff of gas from the Prius and Camry’s oil. The Prius does see 10-20 miles of freeway driving daily but it’s probably not enough to boil off any fuel in the oil. I’m running VRP in it but I think Rotella T6MV might be a better choice.

 

[rijndael]

But honestly, if you tell the dude "Don't do that!! 0w5 is going to harm the engine!" do you think he will listen? Nah..! Might as well hop in for the ride..

People have to acknowledge that someone may know something they don't, and they have to think you're the one with that nugget of knowledge.

This in't much different than older people who refuse to take prescribed medicine for something serious, like a heart attack, because they know more than the doctor or are anti-medicine.

 

[nthach]

People have to acknowledge that someone may know something they don't, and they have to think you're the one with that nugget of knowledge.

This in't much different than older people who refuse to take prescribed medicine for something serious, like a heart attack, because they know more than the doctor or are anti-medicine.

I personally have no problem with “thin” oils as long as you stick with “normal” driving. But Toyota acknowledges thicker oils are better for certain use cases. That said, the Japanese invented thin oils and their driving habits are similar to Americans. The Euros are just adopting 0W-xx and the Detroit 3 are starting to spec them now.