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

I'm not going to say it's just your imagination, but such a hit on mileage would get Toyota in trouble with the EPA. And if we're not seeing a lot of other people with the same observations after the software update, it could be unique to your situation. That doesn't really fix it, but it may help in some way.

 

I did two fill-up calculations, and they confirm the computer results. The computer is reading about 1.5 mpg higher than actual (which is what it has done since new). I had about 250 miles all highway save a few miles, and got 43.1mpg. That sort of trip should have yielded 49 or 50.
I called the dealer and they claim they have no knowledge of the firmware upgrade degrading fuel economy. I am going to try to get in touch with the regional service rep and make it clear that this is not acceptable. I'll post if I get any results.

 

I waited to have this recall performed to hear the feedback first, especially after what happened to the Gen I Insights. So three tanks after having it performed, giving error for driving conditions, temp and so forth, I am happy to report my results are nominal and show no measurable mpg difference.

 

I got the software update for my 2011 Prius in April and since that day (the drive home from the dealer) I went from a consistent 50mpg (for 3 years) to 40-42mpg. Driving habits have not changed. I even waited through 4-5 tanks of gas to notify the dealer of this problem. I made an appointment to have it checked. They said they have never heard of this problem. I told them to check this forum. After waiting quite a while in the service lounge, I noticed my prius outside in the ready line. The service rep said they couldn't find anything wrong and everything is just fine. Funny thing was, no paperwork was generated from the shop showing anything was done at all. The car was washed though.
Today I called Toyota regional just to be referred back to the dealer that did the work. Ugh.
My son has a 2012 Prius and said his mpg increased from 44 to 51mpg after the update. There is something very wrong going on with this update. More people have to call Toyota and their dealerships and Toyota must address this. I can get a real car that gets 40mpg these days.

 

Did you do a verification by calculating the actual mileage based on those tanks of fuel and the distance covered?

 

The other very noticeable difference is miles per tank (between fill ups) Approx 450 total miles to maybe 360-370. The service manager of the dealer called me after I called Toyota Regional and he said anything over 35mpg is "acceptable". That's when I told him to go out to the sales floor and tell that to customer looking to buy a Prius and see if they don't just walk out the door. He was also another one that has never heard anything about the software update causing a mpg decrease. I told him to check this forum or just google it.

I'm bringing it back to the dealer tomorrow for them to check it again but not really expecting anything different to happen.

I hope that Toyota is trying to figure out a bug fix and how they are going to do yet another recall to fix the fix.

 

Just like to chime in again. While we've had no problems post update, the outcome seems a bit of a roulette spin. Hope something positive shakes out, for all those adversely affected.

 

Another Chime in here as well. I was the most worried fellow here on the forums regarding the recall and its effects but had it done 2 weeks ago by my best buddy at his Toyota dealership and absolutely no noticeable effects. Looks like the regen braking is just as good as before - the rims I have never seem to have brake dust on them.

Some have mentioned the ICE needing more effort to accelerate. I am not too sure I feel any difference although throughout my year of owning the car, I remember the engine being loud when going up inclines.

All the best to the folks here with problems. I know that if my mileage drops; even just a little...I would not be able to sleep at night.

 

Science and engineering are not popularity contests. We like to use facts and data, some sort of reproducible set of tests. My testing showed no difference beyond the ordinary variability. Still, I think something makes sense:

• They offer to replace the original software if you sign a contract waiving future warranty coverage.

Bob Wilson

 

maybe your son got your mpg's.

 

We saw the same 8-10 MPG drop. I got back to this forum to look if there were any discussions and found this thread. The drop in displayed mileage and range per tank coincided with the recall update.
I read this thread from the beginning. It really is of little use for any one of us to ask our dealer for help with this issue. Is there someone at Toyota we can get to take a look at our vehicles and determine what has gone wrong? Yes, the battery was disconnected and no, the vehicle is not recovering the previous fuel economy by relearning our driving habits. Interesting comment that the fuel pump measured did not agree after the update and was closer to the previous readings. Will check that on the next fill up.

 

the best way to judge fuel economy is to refill a few tanks and divide mileage by gallons pumped. the display and miles per tank can be deceiving.

 

Sorry, these claims are not credible because none of the reporters have identified enough to replicate the results:

• No speed for the claimed 8-10 MPG drop
• No highway or route for the claimed 8-10 MPG drop

In contrast, I have the patch and verified two data points returned the same MPG as the following chart:



Until the lazy claimants provide technical details to replicate their results, such claims remain not credible. It has to be reproducible, not just 'echoed.'

We had a similar problem with Prius brake pauses in December 2009 through March 2010. There was a difficult to reproduce braking problem but working with the claimants, we discovered the criteria needed to replicate:

1. speed-bump sized pot-hole or even a speed-bump
2. wet or slick road surface
3. moderate braking force
4. speed ~19 mph

It took the AND of these four conditions to replicate the 'brake pause' and later confirm the patch mitigated the problem. But it doesn't matter how many report 'the problem' if none of them are willing to offer any clues how the rest of us can replicate their result. So I soon lose patience with those who complain without credible data.

Bob Wilson

 

it's terrible what your mind can do to you.

 

Oh!!!! Bisco, I feel your pain!

 

you have no idea...

 

I don't question those who are able to show consistently lower MPGs, but I know what it's like to do something and then suspect something's wrong every time you hear a noise that was probably there since the day you bought the vehicle. You're quick to blame the vehicle when there could be other external factors present that would cause the same problem.

Example. I get the best MPGs (from consistent driving habits) during spring and fall when there aren't extreme temps working the A/C or the heater. I also know fuel formulations change throughout the year to address temperature changes. If I had something done right before going into summer or winter, it would be easy to confuse an MPG drop due to temperature and it's effect on how much gas I use as something wrong with the car because of the work that was done.

 

When they document how so we can replicate it, no problem. But without measurements or a well defined methodology, it is at best rumor.

I've shared my baseline performed on a new 2010 Prius in May 2009. I've already replicated two data points and found no difference. If those claiming a problem need to open up with at a minimum, a GPS trace of a trip showing the problem. For example, I have running in our 2010 Prius:

• Garmin nuvi - records each trip track
• dashcam - records GPS trace for each trip
• GPS 'mouse' - next to my right elbow streams GPS data that can be captured by a laptop
• iPhone - the population of GPS apps is huge I choose to download or buy and download one

If the complainers are serious and not just 'yanking our chain,' they can make a GPS trace of a low mileage trip and share it. With the GPS time-stamped, longitude, latitude, and altitude, we can try to replicate their methodology . . . if they are serious about the problem.

Bob Wilson

 

Bob "technically" your are correct, but asking the average commuter to effort and supply this type data is unreasonable within this format. Using mpg tank averages over time usually suffices as "most" of us know our vehicles good enough to see and feel changes aside from environmentals or seasonal fuel blends. While I personally observed no measurable change to my cars mpg or behavior, that does not mean others have not, and many reasons could effect the results...such as improper downloading. This TSB was thrust on the Technicians last minute with a line already waiting, and it's quite possible learning curve errors could have occurred early on even though the software took and registered. Not to say this is the only possibility either, as there could be other variables in effect however, "requiring" a scientific analysis on the part of a consumer should not be expected. Most of us have enough fires to put out in our daily routines already. I am quite sure this will all pan out in time, or just go away.

 

No, just the complainers. I'm working on the principle that they want the problem solved AND will contribute to the solution. We'll handle the technical aspects including loaning or working with them to get the instrumentation. But without the motivation to be part of the solution . . . the complaints become noise.

Bob Wilson