What to do by 100k-120k miles?

On the Toyota owners site, you should be able to see more details of any given item, as long as the dealership provided them.

On my car, when I got it at 105,000 miles, the only additional items done aside from regular maintenance schedule were: 12v battery replaced at 60,000 miles, drive belt replaced at 96,000 miles, tires replaced at 90,000 miles, steering wheel centered at 105,000 miles, and 3 recall repairs. Spark plugs are due at 120,000 miles along with a bunch of other things.

 

Reported for moving to the correct sub : Gen 2 Prius Care, Maintenance and Troubleshooting | PriusChat

 

Do what the manual says needs doing by 120K and hope the previous owner(s) did the required maintenance.

Really only thing might be the inverter coolant.

If you want to be cautious, could do a drain and fill on the transaxle.

My water pump went out a few years ago (60-K-ish), but other than that, the oil changes, the transaxle drain and fill, the inverter service and a new 12-volt battery, pretty much trouble free.

Opps, forgot, cleaned the MAF around 70-K and the throttle body. Also had to replace the rear hatch lock switch about a year ago (a common problem). Oh, the side view mirror, which I managed to break off when I hit a doe last December.

Finally three or so engine air filters and maybe 20 cabin air filters (I had mice problems).

 

Use the Toyota suggested fluid for the transaxle because that is the only fluid that is approved by Toyota.

Sure, experiment if you want. Personally, I am not an automotive engineer. I will pay the price Toyota wants for the stuff.

Same with the coolant. Use the Pink stuff that Toyota approves of. Both for the inverter and the radiator.

Some people have good experience with the Prius Water Pumps, some, such as myself, do not.

Personally, I would NOT replace it if it does not need replacing. It is a big pain. I paid to have it done at the dealership....-- $450.

Spark plugs. I really don't recall seeing anyone claim any particular plug gets better MPG> Denso SK16R11 or NGK IFR5-A11 both would work.

Just for the heck of it, since you don't seem to know much about this car, and both Luscious Garage and I recommend it, I would pull the hybrid battery cooling fan system apart and make sure it is clean and tidy. Prius battery cooling fan cleaning, P0A82 - Luscious Garage | Hybrid Specialists

That could make a big difference on life of the battery. A bit of a PIA, but worth it if that fan is clogged/gunked up.

 

Here is what i recently did at 104k
Dealer:

-Transmisssion drain and fill
-Waterpump/ fix a broken trans seal--had a coolant flush with it.


Myself - very easy to do all by yourself:
-Spark Plugs
-PCV Valve
-Air Filter
-STP in fuel injector (probs not really necessary, but I have long periods of not driving due to work so it doesnt hurt)
-Clean Throttle Body
-Clean MAF


To Do:
Drivebelt---maybe? IDK if it is necessary...don't feel it, may not need it.
Inverter coolant