Battery at 48% - when to replace

The creator of that app was able to massively boost that percentage by doing basic maintenance of deep cycling the pack several times. Maxx Volts and HybridAutomotive make products that will do this for you. Or you can build your own: Build Hybrid Battery Maintenance Gear For Under $100 | PriusChat

To understand how this maintenance works read this: FAQ (Frequently Asked Questions) | Hybrid Automotive and this: BU-807: How to Restore Nickel-based Batteries - Battery University

 

what about the rest of your car, could anything else be causing the drop in mileage?

when the battery gets really bad, you will see the meter fluctuate quickly.

 

have you cleaned the egr circuit?

 

I have a 2010 with just over 200k. I am in the same predicament. I have done the math it would take several years to recover the cost of purchasing a new hybrid battery. I am getting about 38 MPG I am going to drive it till the warning lights come on for the battery. In most cases it won’t get you stranded. I would carry a code reader with you just in case.

 

You could get the Prolong system. I has worked for me.

 

Out of curiosity, when was the last time you have checked out the brakes?
Dragging brakes can cause bad gas mileage..
Check slide pins, and from experience I have found that rear brakes are needing more attention than the front brakes...

Posted via the PriusChat mobile app.

 

Check first link in my signature.

Second to last link in my signature.

 

It's actually really easy but I do understand and feel your pain but it's fun too I guess if you enjoy working on your stuff so it's a lot easier than changing struts or something

 

Wow, that's surprising. I've been using Sunoco for at least a decade without a problem.
I was using Texaco, but those are impossible to find anymore.
I guess it depend on where you are located also. Or one perticular station.
I've been to about 8 different Sunoco's and haven't had any problems.
Maybe you should have used the techron first, then switch brands.

You could also get a sample in a glass jar and see if there is water in their gas.

 

I doubt the battery would drop mpg that much and still not code. I lost 4 mpg when my hv battery went bad. Same goes for gasoline differences. Octane is octane no matter where you get it. Additives vary but they impact injector and valve cleaning, not performance. Excessive oil burning could result in small mpg loss.

Excessive Ready state idling with the ac on will do it as will dragging brakes. High speed driving and lots of fast acceleration can reduce mpg.

 

I use these little guys: at 38+ psi. All it takes is a quick walk around the car. I've got them on my old cars without TPMS too. If the tire pressure is where it should be; you won't see any of the red indicator. But as you found out; tire pressure should be one of the first things to check with low mileage. Dangling garbage, hooked to your undercarriage would be next.

The reason your mileage spiked when you changed gas station; your ECU was remapping fuel mixture due to different gas and the additive. I always run at least an entire tank of gas before jumping to any conclusions. A single trip or two can just be a blip on overall operations.

Hope this helps.....