88 Octane for 2010 Prius - What's up with that?

Just picked up my Winter Gray IV yesterday and the manual still says 88. Glad this thread clarifies things.

 

The owner's manual does state 88 octane; however, all we've seen at the pumps in Texas is 87 and that is what the dealer told us to use.

 

This is somewhat interesting. It's definitely something to consider if you're on a long drive where you'll be passing in and out of a mountain region. Either wait until you're at a lower altitude (with higher octane gas) to fill up or fill up with the higher octane at the higher altitude. To me this seems like the only safe way to do it because you could drive down to a lower altitude with a gas tank full of low octane fuel and suddenly have problems otherwise.

 

Following the link above, I found the Japanese manual page specifying the fuel requirement (assuming that Toyota doesn't tune engines to fit different countries' pollution requirements). It says: Lead-free regular gasoline.
(Relevant page here: --sorry I can't post the link because it's my first post. If you want to see the page, replace the last part of the above link with 2509/M47591_1_6.pdf )
According to a google document, regular unleaded gas in Japan has an octane level around 90. (Sorry that I can't post the link either. Try search these key words: Japan regular unleaded gas octane.)

Being a manual reader, ever since I bought my 2010 prius, I've been adding 89 unleaded, or higher when the gas station I visited didn't have 89. If Toyota manual has a misprint, shouldn't they send a letter correcting the mistake, just like when they send out the recall letter?

 

Octane ratings vary by country. What we call 87 may very well be 90 somewhere else. If you want to compare apples to apples, you have to be willing to do some conversions.

As for the other posts relating to the U.S. manual, it was a misprint. Toyota has been very clear about this. Use 87 octane in the U.S., except when driving at altitude, where 85 is correct.

Tom

 

My owners manuel says on page 105 and again on page 568 "Use unleaded gas (octane rating 87)".

 

Wow, so I have to use 87 now? I cant believe I missed this post before and been using 88 until now, for over a year, since in Utah, Smith's grocery stores always have 88 but other gas stations have 87 which costs about same as Smith's 88. So price wise using 87/88 is same for me but I want to know for sure which one is better for the car so it can last longer? Does anyone know? Prius team?


iPhone ?

 

87 or 88 will both work fine. You won't get anything extra from the 88, so don't pay extra for it, but it's not going to hurt your car.

Tom