I have a 2008 Prius. No where does the manual reference periodic changes of coolant or transmission fluid.

My experience, with conventional vehicles has always been to change coolant every 3 years or 60,000 miles and automatic transmission fluid every 30,000 miles.

What if any change interval should be used on the Prius?


Thanks in advance for your input.

Hi,

You're numbers are correct although actual transaxle oil testing indicates up to 60,000 miles on the transaxle oil based upon these general guidelines:

1. 10k (option) - removes the silicon leached from the sealant material. Not really necessary, it makes subsequent testing of oil provide more useful information.
2. 60k - appears to be good for NHW20 transaxles. If a lot of high-speed driving is involved, sooner. If more modest driving, longer is OK. The first change should be tested but if there has been no earlier change, the Si levels will be abnormally high.

Good luck!

Bob Wilson

After April 3, use e-mail to contact me:

For the coolant, your Prius has two independent systems both circulating the same stuff. For both, the first change is supposed to be at 100k miles and subsequently at 50k intervals.

A recent post at Priuschat hinted that more frequent changes might be better, citing anonymous insiders. If that resonates with you, change the coolants at 30 or 60k intervals. The coolant is not terribly expensive, but getting the electricals loop bled can be tricky. I found the engine loop tricky as well, but with some effort they were both fine.

DAS