2010 Toyota Prius FCD Inaccuracy

The speedometer regulation does not allow to display lower speed than actual, therefore it is intentionally biased to meet the regulation.
The odometer display is relatively accurate, say within 1% with standard size tires, therefore the displayed MPG variance is not caused by odometer error.

Ken@Japan

 

Your the one with only 23 posts out here.
I'm trying to give you the benefit of a doubt as being new and yet so arrogant as that could simply mean your having a bad day.

Try not to be a troll and do a little reading and learn something instead of just stirring hate and dis-contention.

I didn't mean to hurt your feelings and didn't realize you would take it personal.

It is what it is... and not worthy of suing over.

Besides, it would be like David taking on Goliath..... God better be on your side or your not going to have a chance!

I"m sure they courts would agree if you care to spend thousands of dollars to check it out.


I'm not sure if changing tire sizes would help or cancel things out as its pretty tough to find tires that actually get better gas mileage than the stock ones.
That would most likely mean lighter and or thinner with harder rubber to actually get better mileage and simply changing tire size alone may trick the FCD but the tire itself may also change the true mileage and you could end up in worse shape than you are now if your not careful.

Its fun to talk about the reasons and the why and the speculation.

I appreciate Ken's comments as they are always filled with a good knowledge base balanced with common sense.

I admit my comments are not always so balanced.

 

I believe a reputable lawyer will ask "What are the damages?"

• MPG indicator error - none
• failure to raise "check engine" when running out of gas - potential hazard to the uninformed who at low speeds, may get stuck in a bad place. So far, no reports of a resulting accident.
• runaway car accident - significant if you've had one but the rest of us are observers, no affected parties.

There are reports of an accelerator recall along with the floor mat removal to address this risk. We've discussed use of "neutral" as a workaround.

Certainly let Toyota know your opinion but without damages, suing is not likely to get very far. We may not like everything in a car but going to court should be based upon provable damages.

We have a usable, MPG calibration value, 5%, from two sources, data and a second hand conversation. In the world of vehicle problems, it is easy enough to deal with it.

Bob Wilson

 

This is likely why the issue has gotten no acknowledgement from Toyota. The FCD inaccuracy would be classified as a sort of marketing fraud. Those are rarely punished by any authority. The party perpetuating it rarely admits it, so intent is difficult to prove. Consumers expect such abuse and caveat emptor is the predictable response (or YMMV...take your pick.)

The damages are limited to misleading the consumer during the purchasing decision and even there the effect is secondary: it relies on word of mouth/happy first adopters as an influence on the purchasing decision of others.

But why is the discrepancy significant? The answer is in the margins...the differential mpg figure with/without such a discrepancy. When selling a new model that is supposed to be more fuel efficient than its predecessor, one wants to show the widest potential difference. Why settle for 8-9% improvement when you can make it look like 15% to the new owner?

For example, assume the GII was averaging 46 mpg displayed and with little error. Let's assume the GIII gets 50 mpg actual. That is an impressive delta, but due to sample variations, etc. some buyers will actually get lower mileage in the GIII. Throw in a 3 mpg FCD inaccuracy and the display is up to 53 mpg. That makes it unlikely that the new owner will get worse results than in a GII despite vehicle sample variations. And it makes it likely the majority will see over 50 mpg (an important benchmark.) The magnitude of the error is small, but the impact on results is huge.

 

Even without bad intent, these sort of inaccuracies creep into consumer devices from accumulated errors. I can see myself making this decision as the head of the design team, when one of the engineers says "Hey, you know this mileage calculation has a round off error. What do you want to do with the remainder?" The obvious answer: "Well, round it off in our favor."

Errors like this seldom accumulate in a random direction; not when marking folks are involved in the decision.

Tom

 

Civil litigation is not based on only proving damages. There may also be contractual obligations, or warranty claims issues, among other things. No matter what the case, it isnt worth the $$$ to even start a letter writing campaign, much less get an attorney.

I think Toyota could do a better job on the tolerance of their measurements, but they may just be covering their butts at their legal departments direction, for some unknown reason.

 

I agree there could be raised eyebrows at the possibility of the FCD being inaccurate to the positive, but on the other hand, they only rated this car at 50mpg and it does more than that without trying.... so I call it a wash.

If it was all about marketing, they could have at least rated it at 55 or better and gotten away with it..... so I give them some grace here.

 

refresh my memory here. what was that marketing campaign that said i would be getting 57 mpg?? oh, thats right, seems to me it was 50 mpg is what they said.

problem is, there was no marketing campaign on the Toyota MPG figures in the display. they, as always only posted the EPA figures which as we all know, are flawed, dont really apply to the majority, and as it is the government posting the figures, is unassailable in court.

its like suing microsoft because windows crashed one day. dont get me wrong, many have attempted to sue microsoft for all kinds of reasons, many imm are very valid ones. but we need to look at what was accomplished and the effort it took. i think we all agree, there are better ways to spend our time and money.

 

No, it would be analagous to Microsoft intentionally misrepresenting the performance of their system and getting called on it. More like it having some sort of display claiming it had not crashed or experienced and abnormal shutdown when it in fact just had...then denying the problem for months even after it was entered into their system as a known problem. Since Windows has always been a resource pig an actual performance based measure is not possible.

Marketing is indeed what we are talking about: FRAUD. Make the mileage appear better than it actually is by a wide margin, so early adopters who don't do manual calcs will give incorrect information to others and you get good word of mouth and happy customers...because you tricked them.

When such a significant discrepancy is unknown and unintentional it is forgiveable. When it is known (definitely true in this case) and intentional (circumstantial, but there were some claiming some Toyota reps said this) it is a fraud. You can sugar coat it anyway you like, but I'll call it straight: FRAUD. I'm more ethical than that. Some are not. I've gotten into shouting matches with software vendors (and others) because they claimed things that had been reported by the community multiple times were completely new to them and not in their database even though we had cases logged for it. (Since we in the community kept in touch with one another we knew exactly when to yell BULLSHIT!) What they were doing is dishonest and it is exactly what Toyota is doing at the moment. Try to twist it as you like, but that is the way it appears at present.

 

Shawn, its not that what your saying is not right.

However it goes back to the early days of mankind when trading was first done at the trading posts.

The seller bends the truth just enough to flavor and flower his product so the buyer wants it the more to drive up the price and demand for the product.

It goes the other way to.. the buyer downplays the worth and his need for the product but then when he walks away after his purchase and goes and brags to his friends of how good a deal he got.

I too hate non truths and falsehoods. But the real world is filled with them.

When a company is judged as whether they are worthy of being trustworthy and reputable, I guess its always a comparison of policies held by his competitors.

If you look at all the other vendors.... you name the vendor,... cadillac, Ford,
chevy, Kia.. it really doesn't matter.. they all try to sell an idea and a dream more than a real product.

All things considered, Toyota has earned an awesome reputation and its product can be trusted to work reliably for the money almost better than any other name.

IMO, this error "whether intentional or a lack in calculation"... "which I doubt".. both are forgivable in light of what else is going on.

I don't want to even get into a discussion about the Falsehoods, scams, illusions and flat out lies our illustrious President and company we voted into office are doing.

Toyota looks like a saint compared to them.

 

i agree, in reality all marketing is misleading in one way or another. its like those i-phone tv ads.

wouldnt it be wonderful if you could segway from one app to another just like the guy on tv does?? but then again, if you had a simulated screen like the tv guy and not a real i-phone suffering the limitations of an overworked ATT network, it might actually be half as fast as the TV commercial.

but would that be Apple's fault that they have a great product on a not so great network?? or having a great product that suffers inherent unavoidable inconsitent performance that is the main characteristic of EVERY wireless provider??

imm, marketing tells us what is possible, not what is typical

iow, if the marketing campaign only meets or barely exceeds your basic need, move on. you will not be happy

 

So, lets say if you have a choice to have the MPG guage corrected to within 1% (+ / - ), for no charge by Toyota, would you do it?

Alfon

 

sure, why not?? but in the long run, wouldnt matter. would never stop my own calculations anyway.

imm, my only requirement is consistency. i dont care if its 50% off as long as its always 50% off. i can adjust. no biggie. am i gonna complain that i have to fill up the tank every week instead of every two weeks after moving??

the SPM was not accurate either and it was worse. closer to correct, but sometimes high, sometimes low, etc. which basically means i had to rely on personal experience and memories of trends to know where i was at in the tank.

with the 2010, really the same thing, just working with a different set of numbers.

i will say again, cause i think it worth repeating. i am surprised that Toyota has not come out with a flash to address the issue. i would just incorporate it into a day when the other Pri was available. drop it off in the morning, pick it up in the afternoon

 

Heck no, are you kiddin?

We like being told sweet little lies and like being told what we want to hear..... look who we voted in for president?

 

Instantaneous Fuel Consumption Guage - waste of space and for me its seems to be either zero (ICE off) or 10l/100km.

Tripmeter average consumption gets used as well as 5 minute graph.

First fill today, tripmeter aid I averaged 4.5l/100km, calculated as 4.8l/100km. I think that equates to 58 mpg (Oz uses imperial gallon which is a bit bigger) Mixture of 2 country trips, one very hilly. Commuting in medium density traffic daily and dinner and opera one night which had us trapped by roadworks on the freeway for 45 minutes to go 5 km. Similar usage 2 years ago in a Gen II saw the display indicate 5l/100km so some improvement.

Car in Normal mode for the whole time plus some time idling in the drive with the climate control on while I entered some favourites into SatNav and phone numbers into contacts list.

Very happy so far.

David

 

I see a few posts questioning whether the error is in part due to odometer inaccuracy.

That doesn't really come into play here - both fuel pump calculations and FCD computations use the same wheel pulses. Different tires (for example) would affect both calculations equally.

The difference is on the consumption measurment - integrated instantaneous fuel flow versus gas station pump (the latter is easier to make accurate - and is regulated for accuracy!).

 

Cold snap in the area last week.
Computer reading: 44 MPG
Actual at the pump: 41 MPG

 

i am also experiencing a HUGE discrepancy with my computed verses displayed mileage. and its disappointing but only because the error at least, up to this point has not been very consistent.

now, i dont really do a lot of consistent type driving. no long or even mildly extended freeway trips (i fill up about once every 23-30 days!!) so most of it is city driving which has the greatest variability potential, BUT

if having an accurate fuel gauge would mean having to suffer with the lowly 50 mpg EPA, rating, then i prefer the inaccuracy.

now, i got my car at the perfect time to boost mileage, the middle of May. cool, not hot. perfect time to get to know the car and boost mileage. couple that with my standard break-in trip that i have done with all my Pri's and that is the 350+ mile HWY 101 loop which starts and ends in Olympia and circles the Olympic Peninsula (which includes Forks for all you Twilight fans)

now that is a trip with speeds mostly 50-60 mph. at times very twisty, hilly, etc. iow, a perfect back country drive after you get out of town. i did this trip, averaged 68 mpg on the MFD, actual mileage (with a few other trips mixed in) was 62 mpg.

despite the fact that i am also suffering a huge drop in mileage due to cold weather, i frankly dont have that much to complain about

 

Just a comment, I "got" my car in late December, however the papers state that it showed up at port or dealer on 12/1/2009. Side doorjam manufacturer date says November from what I recall, so basically its a newer car. Anyways, my last 4 tanks were off %9.2, %7.0, %7.1, %6.9 respectively. So my guess is that there is no correlation with manufacture date and FCD being off. %7 off is a lot to me. But at least my calculated FE has been 43.1, 42.8, 46.9, 49.2, 48.4mpg, which is nothing to complain about especially in cold Chicago weather.

 

I don't know if anyone has notice in the Gen3 Prius, but my Gen2 is consistently reading ~3mph too high (compared to a GPS) on the speedometer once I go over over ~50mph. This might be a contributing factor in making your cars think that they have gotten better fuel economy that what is real.