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

I think we did as well, due to the car being noticeably more willing to slip into EV, after the update.

I do think some folks have got the short straw though: it seems like the update can get screwed up, and repeat visits to the dealership can also resolve the problems.

I'm very reluctant to cross the inimitable Bob Wilson, but I don't think slavish adherence to scientific method, to the nth degree, is needed for this:

If an owner, very familiar with his/her car, gets the update, and starts seeing a marked mpg drop, it doesn't take GPS tracking and so on, to make a rough estimation.

 

My impression of the update has been: 1) The battery charge drops slower in EV. 2)The battery charge recovers faster in regenerative braking. Both of those things are conducive for more MPG.

I should clarify that my average speed for each tank is about 30 MPH, a lot of secondary road slow driving.

 

^ Your points 1 and 2 say to me that the software has made the HSD more efficient. That's heady stuff. Just might be, if it is, begs the question for Toyota: why didn't you do this in the first place, lol.

 

Every since the recall for the comp. update. I fill my tank and it says I have about 420 miles left till next fill and of course I don't even get the full 420 I range about 380-420miles per tank. This shit sucks. I have a 2013 Toyota Prius 5. Is this ridiculous or what ??? And I do t understand. How people on here r saying they get 600 miles per tank. Wth!

 

Did u find out what's wrong ?? Ever since the recall for the comp. update whatever it was I noticed I don't get as many miles as I use to on a full tank. When I fill my tank it says I have about 425 miles on the full tank till next fill and of course I don't even get the full 425 I get around 380-420miles on a full tank

 

Can someone Please answer my question ?? When u Fill ur Tank up. How many miles does it say u have till u have to fill up again ????
I have a 2013 Toyota Prius 5.i did get the update For the computer , n ever since I notice my tank don't last as long. I noticed I fill my tank and it gives me a reading of about 425 miles till next fill!?! Is this normal or what?? And I don't even get those 425 miles it always less. I'm averaging about 380-415 miles per tank. Is this normal ?????

 

Welcome to the world of Prius and PriusChat. Sad to say, your four posts suggests a problem that in engineering we call "managing user expectations." For example, in October 2005 I got 39 MPG on my first fill-up of our first Prius, a used 2003 with 49,000 miles on it. I briefly thought about turning around and returning the car but then I realized this was 'an expectation.' I decided to find out what the car actually does and have never looked back. You always have the option of replacing that disappointing Prius with something else. But if you are curious, keep reading, or just sell it and get the car you really wanted.

So here are your first four posts, your introduction to the community:

Your expectation is that the car instruments showing miles are remaining in a tank has to be accurate. If that trumps the actual miles per gallon and actual range, you should sell the car. You'll never be happy.

An engineer and private pilot, I know fuel gauges always lie . . . which is why I am still alive to type this message. The only accurate fuel gauge I've ever had was a clear glass tube showing the fuel level . . . and I didn't really trust it. The reason is gas in a tank might not reach the engine. Now it turns out one can use a trip meter to know how much gas remains +/- 0.1 gallon.

The trick is to reset both trip meters to zero when filling up the tank and then dividing the indicated miles by the indicate MPG:

• Actual_fuel_burned_gallons = Indicated_miles / Indicated_MPG

Old pilots use this formula all the time which is why they are 'old.'

The next problem is to measure how many usable gallons are actually in your car. This has to be measured:

• 11.7 gallons - our 2003 Prius measured in nearly 40 'running out of gas' tests
• 12.1 gallons - our 2010 Prius measured in just under 10 'running out of gas' tests

I have no idea how many usable gallons are in any particular Prius, much less yours. But I know how to measure it by deliberately running out of gas which I've done many times with our Prius. Sad to say, running out gas deliberately causes some people to 'set their hair on fire.' But I do it because I want to know when either of our two Prius are going to stop.

So you're in a bad place. You expect the lying fuel gauges to be accurate. They are not but the trip meter, indicated miles and indicated MPG are accurate relative to each other and can tell us how many gallons have been burned. Everything else including the tank capacity has to be measured and the calibration checked if accuracy is important.

Based upon your introduction, you should consider selling the Prius and getting a car that meets your expectations. I know our two Prius meet mine:

A driving stunt completed July 21, 2013 burning 10.9 gallons due to a poor fill-up when I'd inverted the pump handle.

Bob Wilson

 

I got the same results from the recent Toyota Dealer computer update. ( 8mpg drop) Then about 2 weeks later, my 2010 Prius Aux Battery went dead or almost dead.
I called the dealer and they said $300+ to change the battery. They insisted that only they have the battery and only they can change out the battery. Even threatened that I could "electrocute" myself.
I called BS on that one and bought a battery for AutoZone for $192.oo. It only took 4 bolts to remove the battery. 2 holding the battery and 2 holding the terminals. All 10mm bolts.
Well, here is the surprise. I was getting a range of 430 miles every time I gassed up. Now I get a range of 580 miles. And on the way to work today on the interstate I was getting 54 mpg on Eco Mode.
I do know that the computer was 'Unplugged" while I changed the battery. Everyone at Toyota was trying to convince me that you had to have a separate battery with jumpers when you changed out the battery. I called BS on that one as well.
Now I get over 100 more miles range and I went from 38-44 mpg to over 54 mpg.
I know that the Prius that is sold in Europe gets over 60 mpg. We get only 50 mpg here in the USA because that was set by Our Government.
(Remember the Honda Insight that got over 60mpg with those fancy rear wheel coverd?) (That went away fast !!)
It is a scam so that we cannot get the full potential of the cars we drive.
It appears that I must be on the Euorpean standard now. Oh well, it is not good to decieve the customer !!! Makes bad Karma.. like earthquakes.

 

The UK uses imperial gallons, which is larger than a US gallon. That's why they get 60 mpg there.

SCH-I535

 

Canadian car salesmen also love the Imperial gallon. Nobody else in the country has a clue about it, it's been out of use for over 30 years, but hey.

 

That's easy enough to speculate on. It's a complex system driven by complex software. The time to market may have been such that they did not have time to fully optimize the software before the initial release of the car, but in the 4 years since they have.

Frank

 

I spent a lot of not so quality time with the dealer. They once again went through all of the factors (tires, tire pressure, radical changes in my driving, CA summer blend gas, air conditioning in the summer, dirty air filter, etc.), and I believe we discounted all of those (especially since my wife as a 2012 and it stayed the same), and the change happened overnight (as you can see from the car calculated MPGs, which showed as a sudden drop on the dash as I drove and backed up by the calculated MPG). I had all of the records of my MPG and MPH that I could find, and was told that they will get worse millage over time and it was acceptable for them to loose 8 MPGs over a couple of years (I have a problem with that).

I did get one of the Techs to drive while I was in the car. We reset the trip set and he was able to get 44.9 MPG (car calculated), on a specific 10 mile run that I also get good millage. Just driving around, and am back down below 40. It seemed that he expected to get better, but said he didn't have a baseline for that path, although I believe it is one they use for testing cars. Others should have Toyota drive their cars and show they can get closer to the rated MPG on your car and one of theirs for the same route.

They opened a case, and now admit that others have seen this, but with "so many factors" they say it is indeterminate that it is a real problem. My average since the recall has been 38 MPG.is in the range of 37MPG-51MPG which is what they say is within range (even though the drop was sudden), and since their health check diagnostics passes, there is nothing they can do.

There is something wrong... and I guess I need to get a new car, if Toyota will not look into it or back their millage claims.

BTW... they say that Toyota does not read or consider Prius Chat as valid data or multiple concerns about the same issue as useful or relevant to them.

 

Larry,
have you tried resetting the ECU by battery disconnect and testing the 12V battery like the person did above?

 

Thanks for the reply. No, I have not. The dealership specifically said that it is not (and couldn't be) related and would not help (and I could looes all of my preset data). but then again, they don't really admit there is problem. ;o(

I might wait until a few more people try it, or hopefully enough people report it to Toyota that they figure out what is wrong and fix it

 

There's been a few reports here: people go back, get the update done again, and their mpg goes back up.

 

In all the years I've driven automobiles, trucks and motorcycles, that NEVER happens.

Consistent and permanent MPG loss is a sign that something has gone wrong, not a sign of wear and tear...short of needing a complete rebuild of a motor and/or transmission.

 

Good luck with that.

 

we took our car in for service (see previous message) due to the 8mpg-10mpg loss in fuel economy since having the recall work done. my service advisor said that they did make adjustments/calibrations to the (hybrid) system, what exactly i don't know. what i do know is that the car was registering 45mpg on the highway over the weekend, with four adults and luggage in the car, much better than the 25mpg-26mpg that we had been getting in town.

will keep an eye out on the in-city fuel economy and report back.

ps: with the fuel tank filled, the computer would display much less than 400 miles until empty, i just don't remember the exact number.

 

I too have suffered the 8-10 mpg loss after the update. As I do not have the Extended Warranty I fear going back to the dealer about this!! Did they charge to get the update re-done?? Anyone else try the 12v battery disconnect? Can such a disconnect affect the car overall?

Thanks!

 

My car was serviced in the uk 2 months ago. Any way to tell if the update was done?

Also any way to check 12v battery health from the menu?