I ran a test on my 2010 with 52K miles. The CVT fluid came back as being too thin, it also had a little more shavings as normal. They recommend changing it at 40K next time. 30-40K sounds about right to me as I redline my car a lot. As for the Amsoil 0W-20, they came back and said they came back excellent as the oil had less than the normal amount of wear on it after 9200 miles. The only bad thing they saw was more than normal amount of aluminum, most likely due to my old nasty air filter. They recommend going past 10K and into 11K next time. As much as I hate spending the money for Amsoil and the TRD oil filter, I will probably do the same as the car just seems better with the Amsoil over the Toyota and Mobil oil. (I used to get the cold start ticks in the morning when the oil got old)
Ditto. Please post your UOAs, if possible. Since you're in CT, you might consider ordering TRD oil filters from Lynch Toyota. They charge a competitive $12.60 with free shipping within the state.
Old air filters don't usually contribute to contamination until they are so plugged they start to collapse and let air by. If it was the air filter, you would see high silicon from the dirt getting into the engine and high iron from cylinder wall and ring wear increase more than aluminum.
You will find that the numbers will look much better the second time that you do a drain and refill. The wear metals will be significantly lower as the gears will have "lapped-in" during the initial break-in period. The mineral content will also be lower as most of these are from the factory sealants used in manufacturing the HSD. This is why I suggest an early drain/refill at about 30k miles and then every 60k miles thereafter. I am now at 214k miles in my 2004 Prius and have done drain/refill and lab analyses each 60k miles so far (25k more miles to the next one). JeffD
A soil 0w20. It's like 11 a quart now ouch... I got lazy and never got around changing the cvt fluid. I am with you on the 30 to 50k schedule, definitely not lifetime or even 100k
To rephrase my question, which variety of Amsoil 0W20 are you using? I think there are 3 different "flavors". Thanks also for the analysis from the transaxle. Definitely think I will exchange at 30k. Jeff
It sounds like he's using the Signature Series that's rated up to like 25k or something like that. They have cheaper options available, including an "OE" variety that is supposed to be the equivalent of Toyota's. In other words, you could use the cheaper stuff and change with the manufacturers recommendation and not feel obligated to get the other stuff.
I like Amsoil over M1. Use it in my bike but for car seems to be too much $$$.. perhaps worth it if you put a Amsoil bypass filter and run it for 25,000mi interval?
The Prius transaxle is more like a manual transmission than conventional automatic ---- there's no torque converter subjecting the oil to high shear and no oil pump and filter to remove particles left from manufacturing. So once the factory oil is drained and replaced, particles might substantially disappear. I would also think that the helical gears in the planetary unit are not especially sensitive to oil viscosity.
I think you have a good point on the gears vs viscosity. I also suspect that the transmission designers know this and design their gear sets to run in reasonably sheared down oil. I also suspect they aren't very happy about the lifetime oil designation in the owners manuals.
