So I bought an 07...

1) Slow down!
2) Look up "pulse and glide"

 

38MPG for 70 mph sounds about right. If you want higher MPG, slow down.
Spend some time looking up some data and charts that show the MPG Prius will get at speeds between 0 and 70.
If you want to get VERY high MPGs you need to learn how to "pulse and glide".

 

This is merely my experience, yours may vary:

So when I drive the car home I had to climb a fairly long overpass. I had the pedal to the floor and could only go 60mph.
This is not a good sign. The only time a 2007 should max out at 60 mph is if it's towing another one behind it. The only time I ever had anything like that happen was when I bought a 2005 with a failed HV battery and drove it home. Took forever to get up to speed and absolutely HATED any kind of up slope, even fairly gentle ones.


I also notice when playing music and driving with the AC on high recirculating cabin air, the battery on the display went down to one purple bar, then no bars when I climbed the hill.
Was this during normal driving or after sitting idle for a while with the AC running? If you sit parked, running the AC, it will drain the battery down to 2 bars, then the engine starts to recharge it. Then the engine shuts off after and the AC drains it again. Over and over. If you happen to then start driving, the car will act like a dog until the battery has a chance to get up to 4 bars+. If you're driving and the battery goes to zero bars, there is something not right.

It seems I got almost 38 mpg on my drive home (all freeway).
I do between 70 and 85 on the highway portion of my daily commute. I have never been under 42 mpg. The only time I came close to 38 was a trip from Columbia to Atlanta when I hooked up with a few cars in the hammer lane and did 90+ pretty much 80% of the trip. Obviously, your traffic conditions may vary greatly from mine.

It's difficult to diagnose through the internet, but as you say, it does sound like something is off. The 60mph thing is a big red flag to me. Even the mountains of Tennessee and West Virginia haven't caused that kind of heartache for me. It would be a good time to get a Bluetooth OBD adapter and some apps to monitor/test the car while driving. Techstream is your best bet for getting info from the car while not driving, unless you have someone drive while you play with the laptop.

 

Welcome to Prius Chat .

Some questions:

• Was the AC on when climbing the overpass?
• What temperature was the cabin setting for your drive?
• How long of a drive did you have?
• Did the previous owner mention how the car was driven, or if it sat for any period of time?
• What part of the great state of California are you located?

Fast cycling usually is a sign of a weakened battery pack and lack of power on inclines points to the same.

Depending on your DIY acumen, there are solutions to this.

Good luck and keep us posted .

 

What @TMR-JWAP said. You'll need to verify it with Techstream, but it sounds like the traction battery is on its last leg. If 60 mph going up a hill was the limit for the Prius, you wouldn't be seeing them everywhere you look.

As to if it's just a couple cells, that is probably the case right now. Again, you'll need good scanning tools to know which one or ones. But once one fails, the others aren't far behind.

 

Jerry,

You are correct that all of the modules age but your experience is in a hot climate where the major cause of aging is heat. In northern climes heat is less of a problem and many traction batteries get in trouble just due to cell imbalance as they get older. In those cases the individual modules still have some life left. Only those that have had a cell reversal (due to imbalance) need replacement with modules with similar capacity and the whole HV battery needs to be carefully rebalanced.

So your strong suggestion to get a full set of new modules is good advice in hot climates, but DIY module replacement, although a time consuming process requiring a significant learning process, is viable when the HV battery has lived in a cooler climate.

JeffD

 

Well, there is definitely something wrong with it and I'll bet the sell knew it. That would be completely unacceptable to me. I'd take it back. You can do WAY better.

 

Premium gas is meant to prevent knocking in high compression engines. If the manufacturer does not stipulate its use (and Toyota does not for the Prius) it will not do a damn thing other than cost you $.50 a gallon more.

 

Have you ran a car fax to see actually mileage and history?

I think you shouldn't worry about the car just yet, drive it for a month and monitor the oil level. Don't assume anything. If there are no lights on the dash, things appear to be normal. Don't waste your money chasing a problem that may not be there