Mobil One 0 W 30 / synthetic,

Toyota recommends 0w20, I would stick with that.

 

Mobil 1 0W-30 is a good oil. However, it won't meet the xW-20 requirement for the +2010 Prius, so in theory Toyota could deny warranty coverage on that basis

 

I bought the 5w 30 in the big jug, i cant imagine it makes a difference, toyota would have to prove it caused the failure. It wont, the ow is the important part for all the start stop, in florida its bloody hot I want the extra protection a 30w provides

 

No, it shouldn't make any difference. You could probably run 0W-40 and it wouldn't make any difference. One summer I ran heavy duty 15W-40, my fuel economy declined around 2 mpg

I've always believed in matching a viscosity to the ambient climate. In bitter cold temps, especially consistent -30 and colder, you want the thinnest synthetic possible. Eg 0W-20.

In summer, I don't know of any mass produced vehicles that need an xW-50 oil. Some new supercharged Ford Mustangs come with Mobil 1 15W-50, but I wouldn't consider that to be a "mass production" car. The Dodge Challenger SRT/8, with a 6.1 litre hemi, comes with Mobil 1 0W-40. Again, not a "mass production" car by any stretch

At first, I ran Mobil 1 0W-30 in my Prius, with very good results. I then gave the 0W-20 a try, and had slightly better used oil analysis results. So I ran the 0W-20 year round, for over 100,000 miles, using at most half a litre of oil over 10,000 km.

If you run a Prius motor on synthetic from new, you should be safe to use a thinner synthetic. If you wait until the motor has +50,000 miles on it, you may have oil consumption

 

Unless I'm mistaken Toyota recommends 0W-20, but there is a blurb about higher weight oil may be more approiate in high temps, heavy use or something similar in the owners manual. Kinda opens the door for 0W-30 to me.

 

It's not in my manual:
Recommended viscosity: SAE 0W-20 SAE 0W-20 is the best choice for good fuel economy and good starting in cold weather. If SAE 0W-20 is not available, SAE 5W-20 may be used. However, it must be replaced with SAE 0W-20 at the next oil change.

 

I just bought Toyota 0W-20 and an oil filter. Each quart was $7.79 which is costly compared to the jug of Mobil 1.

I'll probably continue forking it out while it is under warranty and then make the switch to Mobil 1 oil with Toyota oil filters for the rest of the car's life.

 

I talked to Customer Service at Mobile Oil. They don't even package 0W20 in 5 quart containers, but they will as soon as retailers like Wal-Mart and Autozone request it. Right now demand for 0W20 is not there. Maybe as the 2010's 5K maintenance schedule gets going, the demand will increase and we'll see those 5qy jugs. Right now you can still get Mobile 1 0W20 in quarts.

 

Emnesto, Great point. If we buy oil at Wal-Mart, we should take the time to find the Auto Dept. manager and ask him/her for 0W20 in the 5 quart jugs. With enough requests, they will ask Mobil, or any supplier, for the product customers are asking to buy. --TK

 

I would like to see a virgin oil sample of Toyota 0W-20. Virgin oil samples of Mobil 1 0W-20 have already been done, it would be nice to see a comparison

 

Page 552 last sentence on the page.
"An oil with a higher viscosity may be better suited if the vehicle is operated at high speeds, or under extreme load conditions"

As I said, kinda opens the door for a higher viscosity oil to me, especially say like Fl. where cold is 50 deg F.

 

I don't know that high ambient temps have much of anything to do with "high speeds" or "extreme load conditions."

I'd hate to present the argument justifying 5 W 30 (or so) by saying "I speed, all the time; usually at least 20mph above the speed limit" or "I usually have five overweight adults in the car" or "I have a Class 3 hitch and pull my bass boat at least two or three times a week."

 

It's 0W-30 was the question, which actually has the same properties when cold as 0W-20. "high speeds" how fast is high? If your that worried about using 0W-30, then don't. But don't act as though Toyota won't allow anything but 0W-20 in the car, because they will allow other oil viscosities, and I saw nothing about boat pulling being required.
SInce they apparently left it up to opinion, my opinion 70 mph highway speeds are "high speeds" and high ambient temps are "extreme load conditions". who is to say I'm wrong? You?
Your opinion carries no more weight than mine, I'll bet, possibly less depending on your qualifications of course.
Opinions are like Belly buttons right? everybody has one.
I guess the REAL answer will only come if one of the Guy's that apparently represent Toyota chimes in.

 

For the North American market, Toyota will claim to use whatever oil is listed in the owner manual. That means for 2004-2009, a 5W-30. 2010, a 0W-20.

What we need is for a 2010 Prius owner in the EU to scan his owner manual section on oil recommendations. They probably allow 20W-50, if the temps are high enough