It's been a while since I battled in this thread. SPL, I commend you for continuing the quest and setting up your own experiment. I will have to say though I continue to be disappointed by your unwillingness to stray from artificial or theorectical results to real condition results. It was a great idea to do real world tests, but then you setup an artificial testing environment with very strict parameters on how the vehicle was to be driven. And then when your test did not clearly back up your suggestion, you popped out your calculator again to skew the results in your favour.

I'm actually surprised myself your results didn't overwhelmingly favour your suggestion given the parameters of the test. I've always agreed that it is a fact that there is energy lost when you have to stick it in a battery first. One of my points from way back is that this whole concept depends on when and how this energy was getting into the battery in the first place. Your test only allows one way, cruising at about 60kph. I know you have lots of math up your sleeve to show how inefficient this is so much of the time. In fact, when reading thru it I began to wonder how the whole hybrid concept works if there are so few times when the energy produced by the engine can be efficiently stored in the battery. Obviously it works though, so there's got to be lots of times when it is efficient.

You're right, I should do my own tests but as you say the weather in the Toronto area is not great for doing a lot of EV right now and its tough for me to have the time to do something like this. Maybe in the spring I will try something, but for now I would offer the following suggestions for a revised test:

Create a route that offers a continual mix of the following driving styles:

• Residential traffic (stop signs, turns, lots of 0 to 60kph)
• Rural back roads (no stopping, 60 to 100kph)
• Main street driving (traffic, traffic lights, 0 to 70 kph)

with good opportunity for a lot of EV runs periodically in the mix of these styles.

Yea, its a lot tougher to ensure each run is comparable in this environment, but thats a fact of real world results. The bigger the data set the better I guess. Why would the test include speeds above EV? Because this test is not so much about running a battery down (especially constantly running the battery low as possible over and over and over again), it's about charging a battery up during various driving in between. That's where the real results can be found.

It might be challenging for me to pick an unbiased route Call me in May

 

alan_in_tempe and Droid13 — Good comments all. You may be right. But, to rise above the category of hypothesis, some actual data are needed! Over to you (seriously)!

Stan

 

Okay, I have let this thing go six pages without saying a word!

First of all, Stan, good work so far. I think what you are trying to prove (or disprove) is impossible in the "laboratory" you have available to you, but I commend you for trying.

Secondly, we may think we know every detail of how the system works and can test the theories discussed in this thread. However, the fact is that until someone goes on a closed course (like Road America or Mid Ohio) and runs a very controlled environment test, we will not have reliable data to support any hypothesis.

If we were to take 3 or more TCH's to such a place, run 2 laps in each direction at 40, 50, 60 and 70 MPH with the cruise control, then repeat with driver "seat of the pants" driving THEN we might have something that vaguely resembles reliable data. Until that day comes, the rest of this is academic.

Finally, the bottom line is, like it or hate it, there are three reasons Toyota designed the HSD vehicles.

1) To help reduce their fleets pollution output and gradually become the greenest auto manufacturer.

2) To raise their fleet FE numbers for various federal benefits.

3) They realized that the time is here to have cars that make better sense for the planet and that there were a multitude of people who would by them if they were easy to operate.

Now, which item was 1, 2, or 3 is debatable and I don't know. However, all the reading, test driving, and real world experience has shown me that Toyota's HSD system is the best balance of the three.

Have a good day everyone!

Larry

 

Boy... the TCH must be a totally different beast than the Ford Escape Hybrid.

In the FEH, forcing EV driving around town nets me 65-72 MPG! And in a 3700 pound SUV no less! Without forced EV I would get about 36-40 MPG around town... more like Ford predicts and advertises.

( and some people still believe Ford "borrowed" technology from Toyota! )
-John

 

Very interesting data Stan. I've driven as far as 75 miles (~ 120 kilometers round trip) and seen 51mpg on the tank average using some EV.

My experience with the TCH suggests that speeds around 40 to 45 mph (64 to 70 km/h) are a "poor" spot in the FE. I notice my FE will climb on the instant MPG gauge from around 25mpg to 35mpg while gently accelerating up a slight incline as my speed passes from the low 40s to 50mph. I've seen this happen enough times that I now avoid constant speeds between 40 and 45mph.

I would be most interested in the results of your test route if you could repeat the same drive, but this time with the cruise control set around 50mph ( ~ 80 km/h.) I strongly suspect your FE will be even higher than the ~50mpg you achieved by forcing EV mode as much as possible.

 

alan_in_tempe, Droid13, Bigsk8r, gpsman1, nash, and others — I have done a very careful experiment, and produced what I consider to be good data to support my contention. It's now time for some OTHERS, like you, who think under that under a different set of conditions they would be able to demonstrate that they can beat the Toyota system by forcing pure-EV mode, to actually make the effort to obtain data to support their HYPOTHESES. Don't keep putting the onus onto ME to do all the work. As I said before, that's unreasonable and unfair. If you believe that you're right, prove it! Make the effort, like I did. I spent the better part of a day to do my experiment, and most of what I've heard since is what I should have done differently. Many of you have much better conditions than we do now in mid-winter in Ontario. How about those of you in warm Arizona, Texas, Florida, etc.? Come on! Put in a bit of hard work yourselves, and gather some good data to support (or refute) your hypotheses. I stand by what I've said until I'm PROVEN wrong. Sorry to sound so tough, but it's not fair to ask ME to do all the work to prove/disprove YOUR claims.

Stan

 

Stan,

I thought my message was even tempered and well thought out, but you tossed me in with everyone else anyway. The point I was making was that until we had multiple cars and multiple drivers with the SAME environment and variable set, the data would be meaningless. On top of that, I was careful to say WE, not you or me.

Being a person who actually has worked in a laboratory, I know that reliable data comes from experiments with the most similar test samples and the least variables. Here is a list of a dozen variables:

Tire Compound (rolling resistance)
Tire Pressure
Wheel Alignment
Vehicle Mass
Cargo Mass
Driver Mass
Fuel Detergents
Fuel Octane
Engine Oil Type
Wind Speed
Wind Direction
Electric Load

Stan, you're probably 100% correct. If so, bully for you!

All I said was that I didn't feel the laboratory available to you (and by extension to the rest of us either!) was adequate. I actually like what's going on here and think doing something next spring or summer as a group would be interesting. If we all changed our oil to the same type, checked PSI, and filled up at the same gas pump, we could even eliminate the worst variables and really go at it.

But hey, I can tell when I am not wanted around, so I'll go hang in some other threads!

 

Bigsk8r and others — Please don't be offended. I didn't intend to offend anyone, but was merely expressing my frustration that everyone seemed to have suggestions about how they thought my experiment should have been conducted differently, or what further experiments they thought I should conduct, but no-one was apparently willing to actually get out and DO an experiment themselves. Some of the suggestions are likely worthwhile changes, that with appropriate controls could explore a broader range of possibilities than I did. I think that it would be useful for some of you to conduct further experiments along these lines, and report back on the results.

However, I must point out that my data are most decidedly NOT meaningless. Under the controlled conditions that I laid out, my data are remarkably consistent, with variability of only tenths of a liter per 100 km. This is pretty darn good! You can't write off these results so glibly. I've been thinking about what other conclusions can be drawn from my data. I think one such conclusion is that the conversion losses occurring in the MGs, dc-to-and-from-ac inverters, dc-to-dc converters, and NiMH battery must be significantly LOWER than I had guesstimated. The two driving modalities that I used gave FE numbers that are not just self-consistent, but also remarkably close to each other. Nevertheless, there are clearly still VERY significant conversion losses occurring in the TCH — otherwise the elaborate cooling systems incorporated for the NiMH battery, and for the inverter/converter electronics and MGs, wouldn't be necessary. The energy that is lost in these conversions manifests itself as heat, of course. I still don't believe that you're likely to better Toyota's performance by forcing more pure-EV mode operation, and then trying to recover the lost battery charge in such a way that you come out on top overall. But, all such claims are still to be PROVEN. And that's my point.

Stan

 

I find this pretty interesting. I've been wrestling with occasional poor FE on my regular commute (poor=<38) up and over the Sepulveda pass in LA, taking the boulevard rather than the freeway. The posted limit in Sepulvedua Blvd is 40MPH, although traffic routinely flows 5-15 mph faster in between blockages. My inward trip is typically jammed on the uphill side and the outward trip is clear on the upward side, and I've been clocking about a 5mpg differential between the two legs, yet on some days I'd get home with >40 mpg on the meter instead of <38. I tried deliberately avoiding the 40-45mph regime last night on the way home and blew the doors off the mpg meter. Just an anecdotal item, not a true data point, but I suspect you have the truth - that there's a "sour spot" in the mpg curve in this range.

 

I have been trying to find a good time to do some experiments as I said I would earlier, but the weather here has been very unpredictable. One day i would have winds over 10 - 15 MPH that would change as the day goes on. Then I had very cold weather, then rain, then ice, the wind, then etc...

All told, my trips to and from work have been ranging between 34 MPG and 44 MPG.

With that kind of swing, I don't feel I can get any meaningfull results until the waether settles down some.

Bob Wilson is tring to set up a Hybrid gathering at the Toyota Factory in Georgetown Kentucky. They have a test track, and one of his ideas was to see if we could use it for various competitions or even some experiments. That might be the ideal way to test this hypothosis.