Put 5W20 in by mistake - should I change it?

[seftonde]

Hello,

I have a 2007 Prius with 30,000 miles on it. I have religiously changed oil/filter and rotated my tires every 5K. I have always bought my oil at the dealer. No problems; consistently high 40's MPG.

Saturday I bought oil and put it in Sunday. After I got the oil drained and new filter on the car, I noticed that all the oil that the TOyota dealer gave me was 5W20.

I know the Prius calls for 5W30. Am I endangering the engine? Should I replace it?

I live in Connecticut, 45 miles to work, mostly highway, outside temp in CT this time of year is 50's at night and 70-80 daytime.

Thanks in advance!
Daniel

[richard schumacher]

Call for jayman!

[hobbit]

Shouldn't be a problem. I did the same thing too. Several other
folks going for highest possible MPG are running 0W20 in their
priuses routinely, even in summer with no ill effects, and the engine
does wind up with less viscous friction. If you're at all worried,
you can probably run the stuff for a while and then do a "short
change" back to 5W30 and think of it as sort of a flush.
.
I used up the rest of my mistaken box of 0W20 by mixing it with
the 5W30 over the next couple of changes.
.
_H*

[Patrick Wong]

Originally Posted by seftonde

...I know the Prius calls for 5W30. Am I endangering the engine? Should I replace it?

I live in Connecticut, 45 miles to work, mostly highway, outside temp in CT this time of year is 50's at night and 70-80 daytime.

Hi Daniel,

Since your ambient temps are moderate, you should be OK. Now that you have this lower-viscosity oil installed, pls let us know if you notice any change in your mpg.

If you were going to visit Death Valley this summer, I would suggest that you revert to 5W-30. Otherwise no worries.

[ZC1]

I just performed an oil change yesterday. Removed the factory goop (which smelled like it had fuel in it or some additive) and put in 5W-20. Accidently, no.

My Toyota Service manager said he puts 5w-20 in ALL the Prius that come in his shop. He said it was for gas mileage purposes.
I know it's not gonna hurt my engine, I've put this weight in V8's to Rotary engines since the 70's but....
I don't drive constantly in subzero or 100+ weather as a norm.

ZC1

[Genoz World]

Just to fill you all in, the 2008 Prius engines are all built a bit TIGHTER in terms of engine tolerances than the previous years, and in turn, the knowledgable dealers will automatically recommend 5-20W.

Thats what i found out, that's what i'm using now.

[ZC1]

Originally Posted by Genoz World

Just to fill you all in, the 2008 Prius engines are all built a bit TIGHTER in terms of engine tolerances than the previous years,

Where'd ya get this information Genoz?
I'm interested in learning more about it.
Thanks.

ZC1

[jayman]

I now run Mobil 1 0W-20 year round - up to 16,000 km - with excellent used oil analysis reports. The oil level will drop about 1/2 a litre over this time, which is excellent oil control

In summer, I have never noticed any difference running 0W-20 vs 0W-30 or 5W-30. In summer, I lost 2 mpg running Esso XD-3 15W-40

[habu968]

Our 09 TCH specifies either 5w20 or 0w20. I lean towards the 0w20 for efficiency sake......

[seftonde]

Thanks all! Excellent advice and much appreciated.

Sounds like I don't have to worry since my temps are moderate. I will probably take Hobbit's advice and do a short change after one or two thousand miles. I will also notice changes in gas mileage and post here as well. My mileage has been pretty consistent since it warmed up outside, so I should be able to get good data.

oops - gotta remember to adjust air pressure again since I rotated the tires - I usually run about 38 front and 36 rear.

Thanks again,
Daniel