2025 Toyota Rav4 personal engine oil struggle.

[SiRDOHC]

Even if it doesn’t burn oil?

Yes, even if it doesn't burn oil. Ringland deposits are sort of like clogged arteries. Not really a problem...... until they are. Think of topping up your old engine like someone who is older and needs blood thinners to stay alive. It's best if you can avoid going down that path when younger with better lifestyle choices.

They both have a 0W winter rating. Fuel consumption during start and warmup is relatively insignificant. You’d never, ever observe a difference you could ascribe to the oil. No way.

Superior winter ratings aren’t there to save fuel when cold. Above the low maximum a 0W oil may be thicker than the corresponding 5W equivalent.

I hear what you are saying. a 0w30 is still more viscous than 0w16 at all stages of a full drive cycle or heat cycle if you will,
despite sharing, within range for a 0W, CCV and MRV specs.

Hear me out. The difference in fuel consumption is large between summer temps and winter temps, even on long trips where the engine is as warm as it can get.

If a 0w16 shifts the dynamic viscosity curve drastically in these much colder drive cycles like the KV40 and KV100 specs suggest they do, it should result in significantly decrease fuel consumption in the winter for my climate and for my shorter trips. Why wouldn't I at least try it, or a 0w20, next winter? I don't think I need to worry about HTHS in this engine in my winter climate.

 

[Hermann]

Change 0W-16 every 5K and drive happy to what ever mileage you choose to endure. It will make no difference if you use anywhere from 0W-8 to 0W-40. Enjoy the car, don't fret over the care.

 

[daniel327]

I'd use Valvoline Synpower 5w40 because I like it and I use it in everything, even my lawn mower.

 

[The Critic]

I'd use Valvoline Synpower 5w40 because I like it and I use it in everything, even my lawn mower.

That was an unhelpful answer to give. Why do you like it and what warrants its use?

 

[Corollaman]

I would just go with a 0w20 oil, you'll have a lot more options.

 

[buster]

VRP 0w16 when it comes out. VRP 0w20 in meantime.

 

[Bkdc]

VRP 0w16 when it comes out. VRP 0w20 in meantime.

There is no meaningful viscosity difference. Look at the curve and use 0w-20. I’ll take the slight extra protection every day. Maybe there might be some difference for someone driving at -20F all day.

My mileage for a Toyota Sienna Hybrid using 0w-20 in coastal Southern California winter (yes, very mild, plumbing to near freezing 33F but usually more like low 40’s at night to 60-70’s during the day) is 36.4 MPG. With 5w-30 it’s 36.2 MPG.

I see absolutely no reason to use 0w-8 unless some personal data shows a significant improvement in fuel efficiency. We are talking less than 1% or so diminishing returns here. Even 0w-16 is suspect. I’m pretty sure almost nobody will notice a difference in mileage between 0w-16 and 0w-20.

For most people who are not living in some sort of extreme weather, anything between 0w-16 through 5w-30 changed every 5K miles will be just fine.