Latest Software Update Safety Recall Resulting in 8mpg less...

You only got 43-44mpg before the flash??? That's pretty low, i'd have to be driving the car pretty hard to get that low. What's your driving route like?? Lots of hills? Gridlock traffic?

Perhaps if you have lots of hills, your prius isn't assisting as much going uphill or charging as much going down. I don't know what they changed in the software.

 

ravencr,

It might help us if we knew more about your driving style along with the contour of the roads in your area. It would also benefit us if we had a better understanding of what your trips are like. In other words, are your trips short, long, city, stop & go, highway, etc. Also what various speeds you drive and what mode you choose (Eco, EV, Normal, Power) will add to help all of us answer your question better. Climate control usage also affects the MPG of the Prius. If you were to share how you are using the A/C - heat along with settings like temp, fan speed, Auto, etc. You will be amazed just how much energy the Prius really uses if you run the climate control in Auto all of the time.

Climate does affect the Prius, but even with all of that it seems your MPG before the update is a little lower than most. I am not saying it is bad, just a little lower than average.

Just want to add that if you add hyper miling to the mix, it will help you to achieve the higher MPG. I realize you say you have tried everything, but wanted to mention it one more time. If you are not familiar with the technique of how to hyper mile a Prius, take the time to study the link below in my signature that refers to that topic. Even though the article is written for a Gen II Prius, the theory and practices thereof are still the same. There is also a wonderful you tube video on the subject for Gen III Prius which is displayed below. If you haven't seen the video before take a few minutes and watch it. Lots of tips and tricks that you can do to make the MPG numbers better over the long haul.

Be aware that the Prius actually operates in five separate modes. There is a good write up that is linked in my signature below. If you are not familiar with the "S4 mode", I urge you to take a few minutes and read up on it. Once you understand how the modes work, you will begin to understand how to get into S4 mode as soon as possible. That way you can take advantage of Pulse and Glide more efficiently. The Prius is great when it comes to MPG, but can go even higher than the EPA when you do P&G along with staying is S4 mode as much as possible.

I hope Toyota can help you with the issue you have at the moment and get you back on the road with better MPG. Give them a chance and be patient with them. It might take the top dog at their service bay and maybe even help from higher up, but I have no doubt they should be able to remedy the situation.

Best of luck to you,
Ron (dorunron)

 

So this morning, I drove our 2003 Prius:

• 10 miles
• light rain
• 61F
• 600 ft. to 680 ft., 80 ft gain in altitude
• 50.8 MPG indicated (53.8 MPG true)
• driving using cruise control

The point is route plays a role; driving style plays a role; vehicle maintenance plays a roll. I could have done the same with our 2010 Prius. But something else the OP mentioned:

"The only reason I drive this car is for the gas mileage, and I can drive a lot nicer car than a Prius that gets gas mileage in the low 30's, . . ."​

If you'd like a 'nicer car', get it, and don't worry about the mileage. Heck, go with a Leaf or Tesla and don't look back. But I doubt we'll ever see the type of information or data that would confirm there is a problem, much less fault-isolate to the patch. Heck, if the OP can't run a benchmark, all we have is an undocumented opinion. There is nothing learned discussing a rumor.

Bob Wilson

 

Funny thing is I think I'm driving like I always have...like a grandma. I never accelerate fast, have always coasted to a stop, and when I take the 6 hour drive to see my father or the 5 hour drive to service some equipment for my side business, I try to get behind a big rig going around the posted highway speed, and draft from about a 3 second rule safe distance. I guess I've always been a hyper miler since I started driving and have been able to achieve over 40 mpg consistently on highway trips with both my 08 corolla and 04 civic. I have been getting 52+mpg highway and city combined since I drove my Prius off the lot brand new last month.

It would seem Toyota built a car specifically for me and my usual driving habits. I don't even make work out of the "pulse and glide" thing. I just "glide" when it's convenient for the driving conditions.

BTW. Fender reissued the 1956 Stratocaster guitar for me too and although my wife keeps telling me to buy one (gotta love a woman like that) maybe I will with all the scratch I'm gonna save on gas.

 

That's the thing about this car. You're gonna get great gas mileage just because that's what it's designed to do.

 

you guys have me worried... I just started getting into the upper 40's low 50 indicated mpg (warm weather, summer fuel) not looking to drop down into the low 40's

 

It's been nearly 2 months since I got the recall done and I still get the same overall gas mileage. Last week I came back from a nearly 400 mile round trip to Orlando and averaged 51 mpg on a mostly pure 70-72 mph highway drive and get in the mid to high 50's as a norm. If there is anything extreme going on, I suggest having it looked at. It sounds like from reports that there are ways that a tech can screw up the update since it has different specific steps that need to be followed.

 

What tires and wheel sizes do you have on the car?

You mentioned "since you've owned the car", which i assume means you bought it used. Perhaps the dealer put on 4 brand new tires when you bought it?? When they do, they usually put on the cheapest set of tires they can buy, where the prius requires LRR (low rolling resistance) tires to get optimal fuel economy. That would explain your drop into the 40's mpg range. Also, if you have the 17" tires, that would also explain another 3-4mpg dip in fuel economy, so then 43-44mpg would be about right.

Also what altitude are you at, you lose 3%hp for every 1000 feet in altitude.

 

Hummm, wait for the warm weather and go back and have the old software put back in. There may be a fee and warnings that your warranty is no longer valid. But at least you'll know; get the car desired, and; the warm weather weather will confirm it was the software and not any, secretive, external event.

The reason why engineers do benchmark testing is because we recognize perceptions can easily be distorted by things having nothing to do with fact. So we use carefully controlled tests that minimize external variables. We do not want to 'fool ourselves.'

I don't mind if someone proposes a hypothesis but if they are too lazy, busy, or incapable of taking an hour or two to repeat a benchmark . . . well it is a tell. The most charitable is they don't want to know, which is also the least charitable as it implies willful ignorance. This is a Galileo moment, a chance to "look through the telescope."

Bob Wilson

 

You may want to take it into another dealership and pitch a dernit.....or maybe not.
Quite frankly I don't think that they're going to re-flash it.
It may be YOUR car (or the bank's car....) but the good folks in Aichi, Japan are still on the hook for safety issues and they're still rubbing a tender spot where they sit down over the UA issue.

How much data did you collect for your efficiency declaration?

I remember that when I first got company car (2010 G3) an associate received an identical car. When we were both on our hypermiling kicks he used to always brag about having an average MPG that was higher than mine, but strangely I always used to get more out of a "tank" than he did.
I fill my tank pretty much at 10 gallons, so when I say that my car is knocking down 49.5mpg, it's not that I drove a longer route at a slower speed to "be more efficient" over one trip.
I measure my mileages by the tank.

If you've dropped 8 mpg suddenly?
There's a problem that needs to be immediately addressed!!
Somebody did something to the car besides reflash it.
Mine was done two tanks ago and I haven't seen much of a difference.

Good Luck!

 

While i agree a basline would be ideal for good quantifiable comparison data. Not everyone has the time or the desire to go that far. It's also not unreasonable to sometime within the lifetime of the vehicle and the many thousands of miles(this is a 2010), to get over 50mpg in a gen3 for at least half a tank or so, even if you do drive it like you stole it.

Since you have a II model, you should really tell us anything you have on there that's aftermarket. Wheels, brand of tires, roof rack etc... How many miles were on it when you bought it? Did you check out your 12v battery voltage and did you try changing the air filter.

What altitude are you at? Looking at a topography map of NC, i see that the appalacian mountain area, about 1/3 of the state is averaged from 2000-6000 feet. Every 1000 feet is 3% loss in power from the gas engine, so 6,000 feet would be an 18% loss roughly. You would be in the PWR area much more often.

 

What did you get with 2008 Sequoia?

 

That's a trick question, those things were lucky to get 17mpg on a good day.

 

I'll ask again.

Do you notice any other behavioral changes in the operation of The Prius?

If it's not some coincidental other factor...such as low tire pressure for an example and it is indeed something that has changed in operation since the update, and I'm more than willing to believe that is possible, then some tangible difference in how the vehicle is now running must exist.

And I highly doubt Toyota is going to remove or reverse an update, that changes parameters that they themselves have identified as potentially dangerous.

And while I think it is possible the update did not take correctly...and/or the process damaged some unit that is now not behaving properly...

I don't believe a MPG drop happens without recognizable changes in how the vehicle is operating.

Do you notice the ICE running more? The state of charge not holding? Less EV operation?

Any tangible symptom since the update, that you can point to and say...this seems to be happening more now, than before?

 

If so, how can you know that MPG changed due to the recall?