I was shopping today at a local canadian tire and for the first time i saw 0W30 from Mobil 1.

Would anyone recommend using this on a 06 Prius?
I know the manual says 5W30; but it also says this is good for a broad range of uses, ie temps. It can get cold here in canada and our summers can get hot as well; it's like hell here, and here is where hell freezes over during winter.

I do understand that the first number, 0W, represents the weight when the engine is cold and the second is the weight when the engine is warmed up.

Also, when i log into the toyota club @toyota.ca, it says for my maintenance that this car can use 5w30 or 5w20 motor oil.

Is there anyone out there using 5w20 or 0w20 motor oil in their prius?

thanks in advance

There are oil testing services that for $15 can give you a report on the used motor oil. You might consider keeping a reference sample, change the oil, and then sending both to the testing service after some given period of service. Compare the results and try another oil. It will take a little time but you'll know.

Bob Wilson

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Thanks for the response,

It it safe to use 5W20 motor oil? I'm thinking of Mobil 1 Synthetic. i would consider testing it only if it's safe to put this in my engine.

Also, i just called a toyota service department and the rep didnt give me a straight answer. I mentioned that the toyota club website says i can use 5w20 or 5w30, and he said toyota recommends using their own (toyota) brand of 5W30.

2001 Prius, 85k miles here. I use the Mobil 1 synthetic 5W30 most often, but have also used their 0W20 product. It certainly pours out of the bottle much more thinly! A major issue is engine protection against wear, but here the data are sparse. My one used oil analysis of 0W20 had the same level of "wear metals" as the 5W30 repeatedly has. This is to say an amount too small to detect by routine analytical methods. In fact the folks at the lab I use (Blackstone) continue to be amazed/impressed at how well Prius engines do in this department.

On this basis I see no reason not to use the lower-viscosity synthetics. However, many drivers will not want to appear to sidestep any aspect of Toyota service specifications, to protect their warranties. I cannot advise you to change things, any more than I can suggest to change synthetic oil only every 10k miles.

In the extremely unlikely event of a Prius engine failure, I would have complete records of the oil changes done, and a history of exceptional engine oil analyses. I confidently expect that the engine (disassembled) would also be shiny-new-clean inside, with no varnish (such as can accumulate with conventional oils). Against this, Toyota might argue that I had violated the terms of the warranty and in so doing had contributed to the engine failure. It woud suck to be them, in that scenario.

DAS

Thanks again tochatihu, I'll pour Mobil 5W30 for now until my warranty expires, and since it's synthetic i'll change every 10k miles which is safe; our engines dont idle like regular cars do. Futhermore, mobil guarantees that their oil will last up to 15k mi anyway.

regards,
gj