Safely substitute 0W-30 for 5W-30 or even 10W-30?

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I have a 2004 Tacoma 2WD with the 2RZFE, 2.4 liter motor. My manual calls for 5W-30 oil.

I'm sure motor oils have come a long way in the last 10 years since my motor was designed. As I learn about oil, I'm thinking that 0W-30 would not only be a safe replacement (because it still protects as a 30 grade oil at operating temperature), but because a 0W would surely flow better (if only even a little) upon start-up (when most engine wear occurs) it would actually do a better job at protecting the engine against wear until the oil reaches normal operating temperature?

Do you think my thinking is correct or off-base?
confused.gif


The only flaw in my thinking is if, when Toyota designed the motor, they wanted (for some reason) the thicker flow of a 5W versus a 0W, but I think that's unlikely. Maybe in 2004 there WERE no 0W-30 oils???

What do you think? Do you think a 0W-30 would be a safe change for the factory recommended 5W-30?

Thank you,
Ed
 
Thanks jayg!

smile.gif


Do you think there's any "down-side" to using the 0W versus the 5W, i.e., leaking or anything weird like that? My motor runs great right now, I'm only trying to (like everybody, right?) have it run as long as it can but I also don't want to CREATE a problem(s)!

smile.gif


Ed
 
Absolutely. They are all nominally 30-weight oils at operating temperature. The 0w30 just "thickens less" as it gets colder. 10w30 is pretty much an archaic grade these days, there's no advantage to running it anymore. It used to be that 10w30 oil had less VII than 5w30, but as the native VI of base oils has gotten higher and higher, the need for VIIs to get to 5w30 and even 0w30 has gotten less and less.
 
Nate - I don't have a clue!

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How would I determine that? I live in Sacramento and it would be RARE for the temperature to get below 30 degrees in the heart of Winter. It does happen...but not very often.

Ed
 
I posted the same question in a related thread. People often say 0w is better for cold temp startup but I want to see some viscosity proof.
 
What is this flow thing ? Pull off the valve cover and see how long it takes for the oil to pump to the top end of the engine. Unless you get close to 0*f even the 10w oils will pump really fast. There has been 0w oils since at least the 1990s.
 
I'm sure the 10W oil will flow...but the 0W will flow better.

The 0W oil will flow faster than a 5W, 10W, etc., at start-up no matter WHERE you live. Since it will flow better at start-up, which is where everyone seems to agree the majority of engine wear occurs...the 0W will do a better job of protecting the engine and reduce wear.

Ed
 
I plugged M1's 0W30 AFE and 10W30 into the widman calculator and at 0C (32F), the viscosity of the 0W30 is 524.6 cSt, and the 10W30 is 615.1 cSt.

(10W30: 10.1, 63.2; 0W30: 10.9, 62.9)

For the same price, for me, any amount faster that the oil gets flowing, the better.

Ed
 
Originally Posted By: Nate1979
I posted the same question in a related thread. People often say 0w is better for cold temp startup but I want to see some viscosity proof.




The testing is at -35C, which is 5C off the -40C Cold pumping viscosity limit for the 0W, and right on the limit for the 5W...the 10W30 at -35C was 5-10C below the cold temperature limits for that lube.

Go up 5C, to -30C, and the 5W would be expected to behave as per the 0W at -35C if you get my drift...at -15C, the 15W would have around the same fluidity as the 0W was at -35...you've gained a 20C starting advantage running the 0W.

Thus my comments in other threads that a 15W is fine for my climate...given that it's pumping, there's nearly no difference in my climate...but in spite of that statement, nearly everything that I use is 5W max.
 
Shannow,
Hey, that's an interesting thought - at, let's say for example, 0 degrees Farenheit, is there ANY difference in the flow of a 0W -vs- 5W -vs- 10W???

I would suspect there still is SOME flow difference???

Ed
 
0F, about -20C, the 10W should behave as the 0W does at -35C (-30F)...in terms of the oil moving through the galleries in the test engine...It's pumped, by a positive displacement pump, so the two remote cam bearings should be pretty close to the same.

Look at the jar pouring test early in the video, and imagine all the beakers moved two places to the right...the 0W will always "flow" better, but it's mass and gravity, not a positive displacement oil pump moving it.

There's a difference in concept between "flow", as you would see it from the beakers (akin to filling your sump from a bottle), and flow as the oil pump makes it happen.
 
Originally Posted By: 440Magnum
10w30 is pretty much an archaic grade these days, there's no advantage to running it anymore.


It's a more durable grade. Less viscosity index improvers and more base oil.
 
Originally Posted By: Merkava_4
Originally Posted By: 440Magnum
10w30 is pretty much an archaic grade these days, there's no advantage to running it anymore.


It's a more durable grade. Less viscosity index improvers and more base oil.


That is true old-school logic, and still prevalent enough that 10W-30 remains the most purchased grade of motor oil in the U.S., if I recall.
 
Originally Posted By: MalfunctionProne
That is true old-school logic, and still prevalent enough that 10W-30 remains the most purchased grade of motor oil in the U.S., if I recall.


Handy that it is, as it's the "most commonly used viscosity" that gives Mobil's AFE it's 2% economy when referenced against.
 
GM only allows 0w-30 in below freezing conditions, and requires 5w-30 otherwise. This is for their older vehicles.

As one other person mentioned, the likely reason is due to the VIIs that can cause faster viscosity breakdown.

Unless it was an A3 rated 0w-30, I would stay with the OEM recommended grade.
 
Originally Posted By: Nate1979
I posted the same question in a related thread. People often say 0w is better for cold temp startup but I want to see some viscosity proof.


Look up the pour point for both oils. The lower the pour point, the thinner the oil at that (low) temperature.
 
Originally Posted By: Ed_Flecko
I have a 2004 Tacoma 2WD with the 2RZFE, 2.4 liter motor. My manual calls for 5W-30 oil.

I'm sure motor oils have come a long way in the last 10 years since my motor was designed. As I learn about oil, I'm thinking that 0W-30 would not only be a safe replacement (because it still protects as a 30 grade oil at operating temperature), but because a 0W would surely flow better (if only even a little) upon start-up (when most engine wear occurs) it would actually do a better job at protecting the engine against wear until the oil reaches normal operating temperature?

Do you think my thinking is correct or off-base?
confused.gif


The only flaw in my thinking is if, when Toyota designed the motor, they wanted (for some reason) the thicker flow of a 5W versus a 0W, but I think that's unlikely. Maybe in 2004 there WERE no 0W-30 oils???

What do you think? Do you think a 0W-30 would be a safe change for the factory recommended 5W-30?

Thank you,
Ed

0W-30 is a lot thicker than the 5W-30 your manual specifies. That's because conventional 5W-30 shears to 5W-20 weight. Synthetic 0W-30 will be shear-stable and retain its 30 weight, unlike conventional 5W-30, which shears to 20 weight.

If you want something thicker, you can use conventional 10W-30, which is very shear-stable and should be even thicker than synthetic 5W-30 and synthetic 0W-30 throughout the OCI.
 
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