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

Call for jayman!

 

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*

 

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.

 

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

 

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.

 

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

ZC1

 

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

 

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

 

But could a dealer claim I violated the warranty by using a non-recommended oil weight ?

My 2008 is new last week with 800+ miles and I want to change to synthetic, perhaps Mobil1 or Amsoil.

Is there any official bulletin that would put my warranty worries to rest ?

 

They wouldn't know unless the engine was damaged. And then only if they could prove the oil caused the damage.

But I'm curious, why would you buy oil from a "stealership"? Especially when you can get the same (or better) oil for much less at say, WalMart.

 

Yes.
No.

 

Anyone concerned about warranties vs engines in Prius, after having done something strange with the engine oil (or not), ought to consider a used oil analysis. Ask that your VIN be attached to the chemical results. Under the very small probability that your engine falls apart, you would then have a point of reference that your oil 'variation' could not have been the cause.

Actually I think that all Prius ought to be getting the UOAs, but that ain't workin'.

 

Oh, you mean like how I had the odd readings from the absolute crap no-name generic bulk lube oil, that was also proven contaminated with dust and moisture?

It really pushed my buttons when Toyota Canada suggested it was my use of Mobil 1 that contributed to the odd readings. Good thing Mobil was willing to step up to the plate for me, once we tracked down the source of the crap - the dealership bulk oil - Toyota Canada very promptly STFU

 

hey ZC1, my friend is a senior mechanic at toyota. i asked him a bunch of questions wheni bought my toyota. that's who i found that out from. he found this out by checking the blueprinted and building tolerances on the 08 engines. i dont know if it's across the board in the other engines, but for the prius, he told me it is.

to answer all the other questions about warranties, i would not know. since i do my own oil changes also................i did my first oil change at 1,500 miles..................however, since the dealer will automatically put 5-20W in ALL the 08 prius's that go in, i dont see much that can go wrong. this would be done without a specific request to put 5-20.

incidentally, i bought my prius, no lease so i'm gonna be changing the oil before or right on 5000 miles, yes i used MOBIL 1 - 5-20W with the stock toyota filter.

 

I wouldn't buy stealership oil and don't think I indicated I would. If it's real Mobil 1 I don't care where it's bought.

Thanks for the replies about warranty. I note that owners manual only says "Recommended", as opposed to "Required to maintain warranty".

So I'll use Mobil 1 0w-20 (?) and have UOAs done every oil change. Is Blackstone the recommended company for UOAs ?

 

Sorry hiremichaelreid. My comment was intended for the thread starter.

But I wouldn't use any other oil weight than what the owners manual suggests. At least during the engine warranty period, to avoid any issues. I gave away several cases of mobil 1 0W-20 oil with my Honda Insight when I sold it thinking I couldn't use it in my Prius. Now I am wishing I had kept the oil. I currently use Mobil 1 5W-30.

 

It might be worth mentioning how to get an oil analysis (UOA). Here is how you do it:
1) Get an oil sample pump. http://www.oaitesting.com/oil_analysis_pump_600px.jpg
2) Get sample bottles and sample tube (if needed).
3) Mail (via regular post office or other service) the sample bottle to the lab
4) Get the results via mail or the internet.
5) Post results to Prius Chat

I have done all my ordering via the AMSOIL web site. They give you everything needed to do the above, including the mailing packages and prepaid labels. It takes a whole 5 minutes to do everything, since you can get the oil from the dipstick access. There are other labs, so I encourage other users to detail how to access these.

 

Good luck finding 0W-20. I looked around and nada. Like when Mobil 1 0W-30 first came out, I could buy it at Pep Boys in Utah, but not in Manitoba. Like we needed a 0W-30 in the blistering Utah heat!

You can use Blackstone if you wish. I use Cat Toromont. Probably easy enough to find a heavy equipment Cat dealer in Ottawa area

Toromont CAT : Oil Analysis Services S·O·S

Not sure how close this depot is to you

Toromont CAT : Branch Locations