Does motor oil brand make any difference for the Prius?

All you can do is look at Amazon comments etc., bottle quality ratings if you have some idea what they mean, but I am just saying I'd be a little weary of cheaper, small off brands unless there is some reason to believe they are up to quality standards.

If Mobil-1 High Mileage is missing the ILSAC rating, that could be a valid reason to pick another brand. Knock on wood I have not had the problem yet.

 

I don't think that they recommend any such thing......at least not because of the different oils.

Different change intervals are recommended for different models........and they just coincidentally recommended slightly different oils too.

It might have something to do with 0W oils being available only in a FULL synthetic and not a blend but I doubt that.

 

They do actually, well I think they do:

Oil change in the US schedule is at 10K miles, and then there's this cryptic note in the 15K service:



And then if you go to footnote 1:



The whole thing sounds like it was written by a committee, and the one or two poor schmucks who actually knew what's what were overridden: makes you want to light your hair afire and run.

 

I suspect it is because of exactly this--non-synthetic oils have to contain more viscosity index improvers to run a low "W" number; VIIs break down in use and change the viscosity range of the oil more quickly than a synthetic with little or no added VIIs.

 

Thanks for this link. Was helpful.

 

Spent a few minutes in Walmart checking out labels-

High Mileage/Synthetics/ 5W-30:
Mobil-1 High Mileage ACEA A1/B1 (no mention of ILSAC GF-5)
Valvoline ILSAC GF-5 (no mention of ACEA A1/B1)
Pennzoil ILSAC GF-5 (no mention of ACEA A1/B1)
Castrol Edge has both ACEA A1/B1 and ILSAC GF-5

In the past I paid more attention to the ACEA A1/B1 which I assume to be a good rating. Castrol has both ratings. It is hard to know if lack of the ILSAC GF-5 rating in the High Mileage Mobil-1 is a shortcoming, or an outcome of what they are trying to accomplish with the oil-leak minimization, older car formula.

PS- I'll say the High Mileage formulations are fairly popular...lots of choice there on the Walmart shelves. Looks like they now have 5W-20 High Mileage now too.

PPS- I see my Walmart now carrying Mobil-1 filters in the store, after several years absence. I bought 2 but was a bit shocked they were about $10/each when I got home and saw my receipt. Anyone know why the added "A" as in M-103A? I'd like to buy a vowel too.

 

Could it be some manufacturers just neglect to mention? I took a look at some bottles of Toyota oil I have: the 0W20 synth has the ILSAC GF-5, but a 5W20 non-synth does not.

 

Mobil 1 0W40 is the only pure synthetic oil made by Mobil. All other Mobil 1 oils have Dino oil as a base. I have been using Mobil 1 0W40 oil and the ICE is running fine. No issues and stil getting the mid 50's in MPG. I would be concern with your mechanics knowledge of motor oil.

 

There is really no need to complicate this, pick a brand that is the right weight and meets or excedes Toyotas specifications
Change it according to their recommendations and your engine will run a long time.

I have lost two engines in my life, one oil related and it was my fault.

 

The right weight is the wrong weight.

 

For that discussion I will gladly bow out and you can contact Toyotas engineers because I really don't know as much as them.

 

Have you heard of CAFE? 0w40 is used in other parts of the noncafe world for Prius.

 

No I haven't, do you drive in extreme heat?

What is your background?

 

Yes I do. But that is not the reason to use 40 weight oil. I see you have been a long time member. You need to research motor oil and CAFE standards that is being dictated to all auto manufacturers and shorting the lives of our vehicles. You can do as you wish with your car, but if you want to make it last you will change your oil at 5k miles and use a thicker oil as the vehicle ages.

 

Thank you I will check into it.

I don't plan on keeping my new Prius as long as I did the old one, but I do all my own work, always have.

 

There are a few threads on this issue and you will see that only in the US are we being told we must use 0W20 oil.

 

I have heard a similar story on another forum about oil. Ford changed their requirements on oil to a lighter weight but not just on new cars but even older cars. I don't remember all the details.

 

Of course years ago Mobil lost the court battle when the US legal system allowed Castrol refined oils to be called "synthetic". So now it is hard to say what is synthetic, thanks to the lawyers.

Did you see the new Mobil-1 1-year drain oils? Almost $40 at Walmart vs. $25 for the normal versions for 5-quarts.

 

The sceptic in me thinks: maybe it's the same oil?

 

Ha, me too but VOA shows add pack differing from other flavors of M1. Said add pack does nothing to point out what makes Advanced Protection such a long drain oil. This leaves base oil open to speculation and, of course, M1 isn't talking. So goes the oil game.

VOA = virgin oil analysis