Lawsuit: Prius recall for inverter software fix hurts fuel economy
 

http://ecomodder.com/forum/attachmen...1&d=1519054183

An electrical engineer who routinely tracks the calculated MPG of his 2013 Prius noticed a significant drop in efficiency following a recall (software change) meant to fix a problem with overheating inverters in the cars.

Toyota recalled 800,000 cars in the U.S. to apply a fix that may have reduced stress on the hybrid components by increasing the share of work done by the gasoline engine. When asked directly, the company hasn't denied this may have affected efficiency.

A class-action suit is in the works:

To add insult to injury, Toyota is also being sued by one of its dealers, which alleges the software update didn't actually fix the problem; it only delays the failure.

Cherry on top: "a complaint by the dealer is now under review by the National Highway Traffic Safety Administration" because the problem can cause the car to suddenly enter "limp mode" (drastically reduced power output) without warning, including at freeway speeds.

Source: Toyota Prius software fix may reduce fuel efficiency, experts say

All things considered(lawsuit), wouldn't it be cheaper to just put in a bigger radiator for the inverter?

I dunno.

The article says the problem is solder joints on the IGBT's that crack due to heat stress/thermal cycling.

Are they bathed in coolant? Or on a heat sink that's bathed in coolant?

Sounds like they may have undersized the IGBTs and failed to deal with conducting the heat away. Solder joints are not typical places to dissipate power, so it must be the devices themselves that are dissipating too much power.

Hmm, my 2012 plug-in must use a different inverter since I was never notified about a recall.

I just have the usual Takata recall to complete as well as something about a high power fuse needing to be replaced.

We haven't (yet) heard anything from Toyota about this recall for our 2014 Prius.

It's possible you had a late model 2014 that was produced after the recall and are thus excluded by VIN. You can go to http://www.toyota.com/owners, create a profile, and add your vehicle. It will notify you of any safety recalls.

The inverter software recall was announced in early 2013 (I had mine done in April 2014), so it might have been done by the previous owner.

According to Toyota's most recent update, no Prius models are involved in the Takata recall.

An apparent drop of 5mpg may be related to any number of things. What was the weather like? Traffic? Did his commute change? Did he start going to a closer grocery store that didn't allow the engine to warm up fully? Did his car develop an undiagnosed dragging brake caliper? Does his car have a clogged EGR? Has his PCV valve stuck? Does he use AC or heat more now than he used to? Any of these things could explain a change in fuel economy as drastic as he claims. Then there's the issue of the claim itself: 49 to 44 over how many tanks? How consistently? How meticulous are his records? Is this claim accurate or an estimate?

As an illustration of a possible counterargument, after I had the recall performed in early April 2014, I had a run of 9 tanks in a row at 60+ mpg, then one 59 mpg, then 6 more 60+, through October of that year. Using Enger's reasoning, the recall improved my car's fuel economy drastically! Except it didn't, because we haven't controlled any variables except the software update, so we have no way of knowing what effect it has on fuel economy by itself.

This is a deliberately misleading statement: the 2014 is rated 49 mpg city because the EPA approved a new correction factor last year applying to 2011-2016 vehicles, leaving the 2010 with the original rating.

I don't know who's right here, but Enger has a lot to prove before I believe his claims.

Given he's an EE who apparently tracks every tank (manually), I'd be inclined to give him the benefit of the doubt that he's comparing apples to apples. I'd be surprised if he made his complaint based on a single data point vs a long-term pattern.

But you know what happens when I assume ...

So those are all valid questions.

I just assumed it was Takata. Perhaps they used a different brand, but the inflator chamber is recalled on my vehicle.

Right, yeah--that was a separate issue. I thought those had all been fixed by now.

Even if he meticulously records every tank, that doesn't necessarily point to the inverter recall as the cause. Another example--my mileage over the last year has been much lower than it was the first year I owned my Prius probably because how far I drive, how fast, and in what weather conditions has changed--I never used to do multiple trips to Chicago in the winter at 75+ mph or multiple trips less than a mile to work in sub-zero temperatures, and now I do. We can't accept Enger's explanation without ruling things like that out, and I'm not sure how he would go about doing that. Toyota has the resources to conduct controlled, instrumented testing on a dyno that would put all this speculation to rest, and I expect if this goes to court we may see some results like that.

Depends on the motivation of the owner. In my case, I ride motorcycles, so airbag shrapnel from side curtains is weighed against the odds of injury riding a machine with no restraint system. Also, my motorcycle awareness translates to my driving behavior as I look both ways before entering an intersection, regardless of right of way. I'm at a lower risk of using the side airbags than most.

Considering the fuse recall now, I might as well kill two stones with one bird.

The reprogrammed behavior should be easy to measure by the layperson. I'm able to see the power output/input of both MGs and the engine using a cheap ELM237 device and the Torque app.

Observing the changed behavior should allow speculation to be made as to how that would impact fuel economy.

I doubt Toyota would be foolish enough to detrimentally impact MPGs without disclosing it to the public, but then again, dieselgate.

Honda did it with a Civic and Accord hybrids to extend battery life at the expense of MPG.

https://www.torquenews.com/1080/car-...rid-mpg-claims

One of my brothers had an Accord Hybrid from that time.

I suppose I have a financial incentive to root for this guy: if the class-action reaches settlement with Toyota, I stand to make money.

06-08 Civic Hybrid only.

New tires dropped my mpg by 5 mpg. 5 mpg sounds like a lot, until you do the math.

The difference between 45 mpg and 50 mpg is 22 gallons a year for someone that drives 10,000 miles per year. We are talking about $1 a week. How much is he expecting to get from Toyota especially after the lawyer's get their share?

I don't know anyone with a job who drives less than 12k miles per year. Do a lot of people actually drive that little? I pack down 2600 miles every month, not including what goes on the company truck.

I'd say 12,000 is about average. In the past I have put in way more than that, but over multiple vehicles. Now I work from home and my wife walks to work. Previously my work commute was 7 miles 1 way. People commuting more than about 30 minutes for extended periods of time are doing life wrong.

Apparently the average registered driver in the USA drives 14,425 miles per year.

My wife and I are both employed full time. We drive to work daily and head to the mountains or beach frequently. Looking at my vehicle logs for 2017:

Spark: 8600 miles
Prius: 8195 miles
Astro: 1692 miles
Total: 18487 miles or 9244 miles each

She is 5 miles from work and I'm 21 miles. My commute takes 50 minutes each way her's is about 10 minutes.

Average driving stats here: https://www.fhwa.dot.gov/ohim/onh00/onh2p11.htm

I have a 7 mile commute for work. I put about 5k miles per year on the car I drive. This is intentional. As much as I enjoy tinkering with them, I don't want to live my life in a car.