5W-20 or 0W-20

[Capa]

Alright, by most important you mean thin but especially at start-up. Because for some that do extended drains I would assume that TBN might be the most important attribute and for others an oil's ability not to shear might be the most important. Everyone has different needs and wants.

To compare the three oils that I am considering:

Pennzoil Ultra 5w20 HTHSV 2.7, VI 154, 40 C cst 47.43, 100 C cst 8.4
Mobil EP 5W-20 HTHSV 2.75, VI 161, 40 C cst 49.6, 100 C cst 8.9
Mobil 0W-20 HTHSV 2.7, VI 173, 40 C cst 44.8, 100 C cst 8.7

So it seems, to compare Ultra and EP, that Ultra is thinner at 40& 100 C and its HTHSV is also lower. But EP has a higher VI. Which is thinner at start up and at what temps woud that hold true? I can only assume that my best choice would be the 0W-20. What would be your second choice?
My GS400 normally drives 6.5 miles to work and then 8 hrs later back to the house. I know, since it's a 17 minute drive, that the oil never reaches optimal temperature. I am assuming that a thinner oil is in order which is why I am going to try a 20 weight---but i probably dont want to go too thin. As you are aware, Toyota doesn't recommend its 0W-20 for this car because, I assume, it is too thin. However, they do allow their 5W-20.

 

[The Critic]

Originally Posted By: partspro
In the past, additional quarts were billed at full retail, we now bill additional quarts at a discounted price IF they are purchased at the same time.


I've never heard of that before. Which chain is this?

 

[LeakySeals]

Originally Posted By: Capa

My GS400 normally drives 6.5 miles to work and then 8 hrs later back to the house. I know, since it's a 17 minute drive, that the oil never reaches optimal temperature. I am assuming that a thinner oil is in order which is why I am going to try a 20 weight---but i probably dont want to go too thin. As you are aware, Toyota doesn't recommend its 0W-20 for this car because, I assume, it is too thin. However, they do allow their 5W-20.


What year is your GS400? What is the recommended weight? Why are you not considering 0w-30?

 

[toneydoc]

Since you state it never gets to operating temp, you can go with the thinner oil and it won't have a chance to thin too much.
And it will get moving a little faster on start up.

 

[Capa]

My GS400 is a 1999. The recommended weight is 5w30, however, Toyota/Leus in Canada permit a 20 weight as recently revealed in a thread.

 

[CATERHAM]

Originally Posted By: Capa
Alright, by most important you mean thin but especially at start-up. Because for some that do extended drains I would assume that TBN might be the most important attribute and for others an oil's ability not to shear might be the most important. Everyone has different needs and wants.
To compare the three oils that I am considering:
Pennzoil Ultra 5w20 HTHSV 2.7, VI 154, 40 C cst 47.43, 100 C cst 8.4
Mobil EP 5W-20 HTHSV 2.75, VI 161, 40 C cst 49.6, 100 C cst 8.9
Mobil 0W-20 HTHSV 2.7, VI 173, 40 C cst 44.8, 100 C cst 8.7

So it seems, to compare Ultra and EP, that Ultra is thinner at 40& 100 C and its HTHSV is also lower. But EP has a higher VI. Which is thinner at start up and at what temps woud that hold true? I can only assume that my best choice would be the 0W-20. What would be your second choice?
My GS400 normally drives 6.5 miles to work and then 8 hrs later back to the house. I know, since it's a 17 minute drive, that the oil never reaches optimal temperature. I am assuming that a thinner oil is in order which is why I am going to try a 20 weight---but i probably dont want to go too thin. As you are aware, Toyota doesn't recommend its 0W-20 for this car because, I assume, it is too thin. However, they do allow their 5W-20.

TBN is not the most important because the lubrication qualities of an oil ALWAYS come first. Virtually every syn oil will last 10,000 miles.
Oil shear is not a big issue today and 20wt oils are generally the most shear resistant grade.

In comparing the viscosities of those three oils, firstly you can ignore the kinematic spec's as they just confuse the issue.
The two 5W-20 oils will have virtually identical operational viscosities in your car on start-up and at operating temperature.
The reason is, the somewhat higher HTHSV of Mobil 1 is compensated for by it's somewhat higher VI.
Mobil 1 0W-20 will be lighter at all temp's due to it's marketedly higher VI.

Of these three oils Mobil 1 0W-20 is the one I'd recommend for your GS400. It's heavier than the Toyota 0W-20 and it's 2.7cP HTHSV is higher than the 2.6cP typical of most 5w20 conventionals.
Is it the oil I'd use? No, with your short commute you'd benefit from the much lighter on start-up Toyota 0W-20 particularly during the winter months. Come the warmer weather of the summer you could add a pint or two of Mobil 1 0W-40 (for piece of mind if nothing else) if you were going to use your car for an extended run on a hot day. Even topping up with some Mobil 1 0W-40, the oil in your sump will still be lighter than Mobil 1 0W-20 on start-up although heavier at operating temp's; that's another benefit of a untra high VI of the Toyota oil.

 

[LeakySeals]

Originally Posted By: CATERHAM

Is it the oil I'd use? No, with your short commute you'd benefit from the much lighter on start-up Toyota 0W-20 particularly during the winter months. Come the warmer weather of the summer you could add a pint or two of Mobil 1 0W-40 (for piece of mind if nothing else) if you were going to use your car for an extended run on a hot day. Even topping up with some Mobil 1 0W-40, the oil in your sump will still be lighter than Mobil 1 0W-20 on start-up although heavier at operating temp's; that's another benefit of a untra high VI of the Toyota oil.





Hey, maybe oil consumption's not such a bad thing after all. Thanks again CATERHAM!

 

[CATERHAM]

Your welcome.
Happy New Year!

 

[Capa]

The problem with the Toyota oil is the price. We have two dealerships here. The first one quoted something like $7.50 a quart. I asked him if he would lower it if I bought a case. He said he could lower it some and quoted $6.50. Now what's funny is that I called the other dealership and the guy said that he believed that the price was $4.20, whether I bought a quart or case. He wasn't positive on the price and was going to ask his supervisor. Obviously it was a new person but I now know how much the dealership pays

Caterham, as you are aware, Toyota does not recommend its 0W-20 in my V8---I can't risk it since apparently there is such a thing as going too thin. I'm noticing that Pennzoil has a 0W-20. It seems to be thinner than Mobil's too. Hmmm?

 

[CATERHAM]

Originally Posted By: Capa

Caterham, as you are aware, Toyota does not recommend its 0W-20 in my V8---I can't risk it since apparently there is such a thing as going too thin. I'm noticing that Pennzoil has a 0W-20. It seems to be thinner than Mobil's too. Hmmm?

It's strange that the Toyota 0W-20 (and the other Japanese OEM 0W-20's) are so expensive in the States. We get the same oils imported up from the States and they retail for about 5 bucks/L and you can negotiate them down from there.

Actually it's very difficult to go "too thin" and with the way you drive your car it won't happen especially during the winter.
But if you're more comfortable about choosing something else, especially if you can get it for a better price I understand.
My main point is that you can still stick with the 0W-20 grade as they're all heavier than the Toyota 0W-20.
My second fav' 0W-20 available to you is the Idemitsu made Mazda and Subaru 0W-20's.
Pennzoil Platinum 0W-20 is also an option with a decent 175 VI. And as you pointed out it is somewhat lighter than Mobil 1 0W-20.