My wifes 09 vs my 08.

Ok, Long post INC. See TL;DR at bottom .

I purchased my first Prius in May 2016. We got a 2009 touring with 119k (I think...) miles on it. Extremely happy with it. Now, less than 2 years later, we have 143k on it. For a while, I was using it as a daily driver in Texas making a 32 mile each way commute to work and back. It was our only vehicle for about 15 months (from the time we purchased it, to the time we got my truck). When I drove it, solely, I would see MPG around 44. It was being used 40/60 city/highway, and when on the highway I cruised at 80-85 MPH. So I was happy with those results.

Then I got a truck, and we moved to Colorado. My wife was the only driver (90% of the time) of the Prius. I have read all the "Lower fuel economy in the winter" posts, so I was expecting lower. My wife is the type of driver who gets in, floors it at every green light and slams the brakes on at the last minute (despite me showing and telling her how to properly drive it...) So also expected lower fuel economy. Well as it turns out, my new commute is roughly 84 miles... (long story, even longer than this post). So we sold my truck :*(. I drove her car for about 3 weeks, and the best fuel economy I am seeing is about 36 mpg. Which, again, colder Colorado weather. Another factor is we have studded snow tires on her car...

About 2 weeks ago, I picked up a 2008 with 117k miles on it. And here is where my concern comes into play. With my car, it feels as though I have a lot more power. And I am seeing 42 MPG when I don't try (AKA, drive like my wife) and 45-46 when I do try. (Again, this is winter driving)

Before I got this car, I was happy with 36 mpg. Now I am concerned that I am seeing the beginning of the end of the HV battery.

Here's where I need input:
Should I be concerned about the HV battery in her car, or is the mileage difference and different tires enough to make that much of a change?

I have read this entire post:
Quantitative Results of Grid Charge Discharge

And I have determined that if I do end up with a grid charger, it will be from Hybrid Automotive. @jeff652 was extremely active and more than helpful throughout that entire thread!

TL;DR
Have two prii, one gets better MPG, should I be concerned?

 

I will do the 12v check on her car when I see it next (should be on Thursday). Wheel alignment is good, and I do the oil and check it excessively (at least once a week). I am paranoid she will run out, and her car uses 1qt every 2-3k mi.

And I would try swapping tires, but she’d have to drive my car because now that she has them, she says she won’t drive in winter without them lol.

EDIT: Although, then it would give me the opportunity to drive her car with fewer variables... duh

Yes. That’s why I figured I’d start with this post .

I guess if I am desperate I could hit up Boulder Prius. I commute from Ft Collins to Castle Rock, so Boulder is not that far off my commute. My issue is, I don’t like other people to do any work on my cars. It seems like every time I give in, someone messes something simple up, and I’d rather be in control.

I’ve been through 4 tanks, just filled up last night for the fifth time. The dealership I bought it from filled me up (it was the typical empty tank when I test drove it...)

As much as I’d like to jump onboard that train, it’s hard to justify that to the wife ><. That’s a lot of money for a preventative maintenance procedure.

 

Yeah, ok.

Time to hook up the tech stream. I purchased one but have yet to use it. No time, too much working...

 

And honestly? I would take that answer. I think I will finally hook up the tech stream and run a battery check. I will update when I have done that .

 

Yeah, I’m aware of that, it’s just the upfront cost will be like $600 for both cars. And if my batteries are ok, then I would rather not right now :S.