Please help me in interpreting this chart

[crinkles]

THis is from my owner's manual.

I live where it never freezes (comes close) and may reach say 40 degrees celcius / 100 F.

If i followed the chart I can't use 5W-30? surely that can't be right? THe only difference would be cold start viscosity (which would be less for the 5W-30 and therefore BETTER for the engine)

And, it is well known that a 20W-50 is too thick at operating temps for this motor (and liekly the 40 weight too). Why would Toyota recommend it?

The US model year for my car lists 10W-30 or 5W-30...

 

[coffee]

I would think the 10w30 you have would be perfect for you to stick with. It is a great oil and fits any situation.

 

[crinkles]

Originally Posted By: coffee
I would think the 10w30 you have would be perfect for you to stick with. It is a great oil and fits any situation.


but why not 5W-30? would it not give superior wear protection on start up?

 

[highe]

I thought a 5w30 is still a 30 weight at operating temperature.

 

[Camu Mahubah]

What's it say on the oil fill cap?

 

[demarpaint]

According to the chart 10W-30 would be the "best" suited oil for your application. However in the real world 5W-30 is the best, because of the cold start protection.

I had this discussion with the Chrylser people where they ONLY spec 5W-20 for my vehicle, and I know that 0W-20 would be better for me in the winter when I go upstate NY.

I would use the 5W-30 without hesitation, but 10W-30 is still a good oil, and might be less likely to shear.

Frank D

 

[Shannow]

crinkles, a million toyota engines have survived on 20W-50, and something W-40 for ages in Oz.

I think that a 10W-30, or 0,5,10,15W-40 would do you well up North.

I started straight 30 at -7C the other day, and no more/less clatter than any other day.

 

[Camu Mahubah]

Wow! That's so cool! When you say "Up North" you mean "hotter" than "Down South". Right?

Exactly the opposite here.

 

[Shannow]

No [censored] Batman !

yep, there's bananas north of here.

 

[crinkles]

Originally Posted By: Camu Mahubah
What's it say on the oil fill cap?


It doesn't say....

 

[crinkles]

Originally Posted By: Shannow
crinkles, a million toyota engines have survived on 20W-50, and something W-40 for ages in Oz.

I think that a 10W-30, or 0,5,10,15W-40 would do you well up North.

I started straight 30 at -7C the other day, and no more/less clatter than any other day.


Well the 15W-40 types ar dirt cheap (shell helix SJ, suitable according to my owners manual) @ $16 / 5L so its tempting.

Must say I got my 2nd best mileage the other day using 10W-30 durablend but I cant see a 40 wt being much difference.

 

[Camu Mahubah]

Originally Posted By: Shannow
No [censored] Batman !

yep, there's bananas north of here.


Just practice...As An American, I must appear stupid or I could be taken for a deviant!

 

[crinkles]

Originally Posted By: Shannow
No [censored] Batman !

yep, there's bananas north of here.


and its freezing down south... dang southerner types...

 

[crinkles]

Originally Posted By: Camu Mahubah
Wow! That's so cool! When you say "Up North" you mean "hotter" than "Down South". Right?

Exactly the opposite here.


our toilets also go counter clockwise. pretty neat

 

[d00df00d]

Here's why it says 10w-30 is better than 5w-30 for high temperatures.

With some conventional oils, especially old/uber-cheap ones, a 10w-30 will be better than a 5w-30 at really high temperatures. This is because primitive (read: non-modern) technology requires a 5w-30 to be made with thinner basestocks and more polymeric thickeners, and that could lead to breakdown, deposit formation, and poor performance at high temperatures.

So, basically, your manual specs 10w-30 just to cover for the possibility of some cheapo [censored] in the Gobi desert buying the cheapest grocery store brand motor oil he can find.

Your manual also says 15w-40 and 20w-50 are okay because they probably are. Remember, this chart is not about what's best for your engine. It's about what's "acceptable to use."

If you go to a store today and buy a good, modern oil -- synthetic or not -- you could easily run 5w-30 in a warm climate and it'll be okay.

 

[glennc]

I'm assuming this chart is old, and the recommendations are based on the oils available when it was first printed. Back then (what are we talking - '80's? '90's?) today's base stocks were not even available, and in addition the specs allowed a 5W-30 to be a relatively weak oil with lots of VII that would shear very quickly.

Today's SM 5W-30s are much better. However, since you have high temps and not low temps, I'd go heavier. I'd think about using the one common grade not listed on that chart: a 10W-40. Today's 10W-40s are very good and won't be overly thick when cold. I would choose that above a 15W-40 or 20W-50, personally.

However, I'm sure all would work very well.

 

[Ken2]

There are cultural considerations when spec'ing a motor oil. Many parts of the world have used high viscosity oil for many years, and many of the people there believe that this is the right thing to do. In the past, with lower quality oils, especially some very low quality counterfeit oils, the high viscosity was the only thing protecting the engine.

Times are different. Oils are different. People change more slowly than oil chemistry changes. There may be no changes to that engine model engine, but the 2008 version may spec 5W-30 or 10W-30.

I'd use either of these lighter vis oils in your engine. Their main advantage will be a couple of percentage points of fuel savings.

 

[crinkles]

Originally Posted By: glennc
I'm assuming this chart is old, and the recommendations are based on the oils available when it was first printed. Back then (what are we talking - '80's? '90's?)


This model and engine I think was introduced in the early 00's, the first Australian version was 2002.

Considering Castrol GTX 10w-30, Mobil1 10W-30 or 0W-40, or Durablend 5W-30.

 

[glennc]

Oops, wrong guess apparently. Still, I've seen lots of similar charts, where a 5W-30 is spec'd for lower max temp than 10W-30, and I suppose the same reasoning applies, as pointed out by others. The 5W-30 is built on a lighter base stock and much more likely to shear in use.

 

[crinkles]

thanks everyone for the replies, that clears it up a bit. By the same reasoning would a 0W-30 or -40 also not be as good?