Just drove 1/2 way of my trip [1500 miles] averaged = 41.1 mpg-Original hybrid battery

I once did an 80mph banzai run to Phoenix and back in 115F weather with the a/c going full blast. That's the only time I've ever seen a figure that low.

 

Regardless of where he's going, it's uphill, so that may have some effect. Let's see how it looks on the way home.

 

I'd say that's about right for those speeds. And I assume there was some elevation gain as well.

 

Consistently reduced fuel economy and faster SOC depletion are possible indicators of a weakened HV battery.

 

Clean your battery fan if you haven't lately. It made a noticeable difference in mpg the last time I did. Every time I do coolant change 50k miles, I wash this fan. Water doesn't appear to damage it in my experience.

Watch your battery on long trips via OBD2 -> Bluetooth, the temperature of 'battery sensor 2' could be around 115F, when it gets to 130F it starts refusing to charge and mpg will go down to 35-40.

Most people think their battery is bad but its not, its just getting too hot especially on long trips its more noticeable.

Also check your tire air pressure, seems insignificant, but its not in my experience. Mine was 30psi, and it was suppose to be 45psi max. Once I put the correct amount of air in my tire, it went above 50mpg driving normally instead of 44-45.

 

I'm new to the group and my new-to-me,aged prius/HV battery. Two more potential sources of low mileage in addition to HV battery health, driving style and tire pressure could be: 1. dying 12v accessory lead acid battery - the ICE (engine) comes on more when the accessory battery is weak and not holding a good charge, I've read on PC. 2. The AC, electric cabin heat and defroster accessories use a huge amount of power. If your driving requires these, it makes sense that your mileage would be worse.

 

SPEED is the biggest factor in fuel mileage, no matter what kind of vehicle you drive.

A conventional hybrid car gets little to no benefit from the hybrid battery when your speed is constantly above about 70 MPH.
Some designs won't even try to use the battery.....or charge it much.....at those speeds.

 

@Sam

I actually was able to use pure battery, no engine at 70mph not long ago on the 15 freeway north.

Posted via the PriusChat mobile app.

 

Going downhill ?
Decelerating from 80 MPH ?

Given the way that my C works, I find that a bit hard to believe just in general.

 

It may be hard to believe, but it doesn't mean it didn't happen.

 

Sure. Even if it wasn't actually designed to do that. Right.
More likely a misunderstanding, I think.