0W16 + 0W20 = 0W18? Mixing 2 qts Castrol 0W20 with 2 qts Toyota 0W16!

[Oliveoil2]

My only thought is they might be including it in terms of the "package" that we've already gone over with manufacturers seeking to reduce warm-up time. So, while thinner oil itself doesn't directly contribute to faster warm-up (and in fact would work against it slightly), its use, to reduce friction and power loss, while at the same time using these other mechanisms to heat the oil and expedite the warming of the coolant as a means of improving the overall efficiency of the package "fits".

I’ve read tour response again and it make sense! I appreciate you taking time to respond to my question.

 

[OVERKILL]

I’ve read tour response again and it make sense! I appreciate you taking time to respond to my question.

You are quite welcome!

 

[FZ1]

OK, so instead of regurgitating oil company marketing, put on your critical thinking hat for a minute.

1. Oil pumps are positive displacement, which means that as long as the pump isn't on the relief, the same volume of oil is being forced through the engine. So "flow" is the same provided those caveats are observed.

2. The only place #1 fails to address is cylinder wall lubrication, which is achieved by the shearing action of the rod on the rod journal, which forces out a spray of oil that lubricates the bores. Some engines also have piston cooling jets that spray on the bottom of the pistons to aide in heat removal (my 6.4L has these). Both of these mechanisms work better with thinner oil, and since all oil thickens when it cools, the closer to "hot" viscosity the oil is, the more effective these are going to be. In application, this has very little impact on longevity however.

3. It does not lead to faster engine warm-up as we've already discussed. An engine's generation of heat is directly tied to how much fuel it consumes. Remember, engines are horribly inefficient at converting chemical energy into mechanical energy, the biggest share of that chemical energy ends up as heat energy. Ergo, the more load that's on the engine, the more fuel it is going to use, the more fuel it uses, the more heat it is going to produce and the more heat it produces the faster it is going to warm up. As I already mentioned, you also have the shearing effect of the bearings on the oil itself and heavier oil generates more friction, which in turn means more heat, as well as more drag, which means more fuel. Follow?

4. Fuel economy. Absolutely. As I already noted, the purpose of using thinner lubricants is to primarily improve fuel economy during the period where the engine is least efficient, and that's during warm-up. The closer the oil is to operating viscosity, the less drag is placed on internal parts, the easier the oil pumps, and the less fuel the engine has to use to provide the same power. While these are all small fractional gains, they do add up to a measurable impact on fuel economy.

As I already said, OEM's have been working to decrease warm-up time of both oil and coolant and they've been doing this by:
1. The fitment of electrical fans in place of mechanical fans
2. The fitment of coolant/oil heat exchangers. Coolant comes up to temperature MUCH faster than oil does (where does the majority of that aforementioned heat energy go? Right into the coolant) so these devices use the coolant to heat the oil, rapidly reducing viscosity, drag, and the impact on fuel economy.
3. The fitment of grille shutters. This is probably the most recent "tweak". Block off airflow through the radiator, which causes the coolant to come up to temperature faster. Couple that with a coolant/oil heat exchanger and you significantly decrease the time required to get both fluids up to operating temperature.


Also, keep in mind, the number in front of the SAE grade, so in this case, the 0W-xx is the WINTER rating of the lubricant. A 0w-40 is significantly heavier than a 0w-20 and a 0w-20 with a low VI can be heavier at most temperatures than a 5w-20! However, the beauty of the 0w-xx Winter rating is that it works anywhere from Texas to Alaska, which allows these oils to be "universal", which is why they've become so popular in recent years.

Now, that was a great explanation!

 

[JeepJKU08]

I don't get it. Why mix different brands let alone viscosities? Are you trying to play chemist? Use what it calls for and pick a good brand and call it good. Don't understand why some folks feel the need to reinvent the wheel.

 

[GyroJed]

My concern is the change of summer temperature to above 100 degf. I always use the W16 Synthetic in my 30KM Corolla. It has received 3 oil and (Napa) filter changes so far. It gets no hard driving, and the valves are quiet. Sport mode never used. The oil is as fine as sewing machine oil and I never liked that for summer. Since Toyota frowns on the 20W, we are left with coming up with an alternate weight.

 

[PimTac]

My concern is the change of summer temperature to above 100 degf. I always use the W16 Synthetic in my 30KM Corolla. It has received 3 oil and (Napa) filter changes so far. It gets no hard driving, and the valves are quiet. Sport mode never used. The oil is as fine as sewing machine oil and I never liked that for summer. Since Toyota frowns on the 20W, we are left with coming up with an alternate weight.

No need to worry. The cooling system takes care of the heat.

 

[BMW Dom]

Since Toyota frowns on the 20W, we are left with coming up with an alternate weight.

Is Toyota going to arrest you?

 

[kschachn]

My concern is the change of summer temperature to above 100 degf. I always use the W16 Synthetic in my 30KM Corolla. It has received 3 oil and (Napa) filter changes so far. It gets no hard driving, and the valves are quiet. Sport mode never used. The oil is as fine as sewing machine oil and I never liked that for summer. Since Toyota frowns on the 20W, we are left with coming up with an alternate weight.

If they “frown” on a 20-grade what alternate grade do you suggest?

 

[Titan]

You are quite welcome!

I understand the hydraulics of a positive displacement pump...if you assume no cavitation or "leakage", one rotation puts out X volume. But, I've read where some racers state they use slightly thinner oils in order to drop the oil temps. Is this due to an oil pump that is spinning so fast it generates enough pressure to go into partial bypass, therefore diverting some of the potential flow to a shunt that misses cooling some of the engine parts? Is it a myth? Or, something else (such as leakage at high pressures)?

 

[OVERKILL]

I understand the hydraulics of a positive displacement pump...if you assume no cavitation or "leakage", one rotation puts out X volume. But, I've read where some racers state they use slightly thinner oils in order to drop the oil temps. Is this due to an oil pump that is spinning so fast it generates enough pressure to go into partial bypass, therefore diverting some of the potential flow to a shunt that misses cooling some of the engine parts? Is it a myth? Or, something else (such as leakage at high pressures)?

It's due to thinner oil generating less heat in the bearings by the shearing action, which in turn will slightly reduce oil temps.

 

[kschachn]

Lower oil temperature relates to less shear heating in the bearings or the pump and less energy dissipated as heat.

Oops Overkill beat me to it.

 

[Titan]

Lower oil temperature relates to less shear heating in the bearings or the pump and less energy dissipated as heat.

Oops Overkill beat me to it.

Thanks to you both. I just never envisioned bearing shear to raise temps so much. The vast majority of total heat generation is combustion heat, of course...I just thought combustion heat source was so great that heat from bearings would be miniscule percentage-wise. Come to think of it, now I recall reading somewhere about a decrease in viscosity of oil because of the heat generated as the oil is compressed in the bearing. Although obviously not an expert in the field, I do find the physics interesting.

Thanks again!

 

[OVERKILL]

Thanks to you both. I just never envisioned bearing shear to raise temps so much. The vast majority of total heat generation is combustion heat, of course...I just thought combustion heat source was so great that heat from bearings would be miniscule percentage-wise. Come to think of it, now I recall reading somewhere about a decrease in viscosity of oil because of the heat generated as the oil is compressed in the bearing. Although obviously not an expert in the field, I do find the physics interesting.

Thanks again!

You are quite welcome. @Shannow has posted on the subject of bearing heat generation (he's a mechanical engineer specializing in bearing design) so if you want to read some more on it, you could search under his username.

 

[GyroJed]

If they “frown” on a 20-grade what alternate grade do you suggest?

0W18

 

[demarpaint]

0W18

At the moment that grade doesn't exist.

 

[OVERKILL]

0W18

Since that grade isn't defined in J300, how do you propose one obtain it?

 

[PimTac]

I think we are being played.

 

[Shannow]

You are quite welcome. @Shannow has posted on the subject of bearing heat generation (he's a mechanical engineer specializing in bearing design) so if you want to read some more on it, you could search under his username.

These are a couple of good examples, note the heat generated, and that it's flowing INTO the block and rods, not FROm them into the oil.Did some experiments back in the day with 5W30 and 20W60 in my mower at 5 minutes stable full noise, and there was about 35F difference IIRC.

L67 Caprice, same commute, but holding a lower gear to hold 3,500RPM at cruising speed, dropping a thermocouple down the dipstick hole, there's a massive difference for the same road load.

If you want to fast warmup, hold 2-2,500 RPM until you get out of town, and the coolant will be notably warmer when you hit the highway.

 

[Graham Piccinini]

What are your thoughts?

Here is how you hit even better MPG. 70? 80? 100? Idk... But read this thread, then buy some 0W5 racing oil (NEO/RedLine/Driven). If it worked in VW 1.9L TDI for up to 370K miles, then your Accord Hybrid may actually be alright, considering your hypermiling driving style. Keep it at 3k-5k miles per OCI.

 

[blufeb95]

Here is how you hit even better MPG. 70? 80? 100? Idk... But read this thread, then buy some 0W5 racing oil (NEO/RedLine/Driven). If it worked in VW 1.9L TDI for up to 370K miles, then your Accord Hybrid may actually be alright, considering your hypermiling driving style. Keep it at 3k-5k miles per OCI.

Neo only publishes a KV40 and from what I've dug up about it they were never to forthcoming about the KV100 or HTHS viscosity, 0W5 is not a grade per the SAE, the Neo stuff appears to probably be 0W16 or a thin 0W20