That would be cool! Imagine the data that could be had if several cars (and their humans) showed up and were willing to participate. We could do all sorts of things with the variables. Octane, load, PSI, etc..

I could even host some folks if it's on a weekend. I live about 90 minutes from the plant.

 

A gathering at Larry's house huh...

 

ag4ever, Bigsk8r, and tnsig — Your responses have re-encouraged me! Those sound like excellent ideas! If something like that could be arranged at Toyota's Kentucky facility, then with appropriate controls, we could potentially get some very good data.

nash and scottzorch — Interesting comments! This is something that could be tested under controlled conditions as suggested above.

Keep the ideas coming for further experiments, and start thinking about how extraneous variables should be controlled!

Stan

 

Yea, think along the lines of four or five cars driving the same test track at a fixed spacing using the same driving technique to verify the MPG comparison between cars, then those same cars all travelling the same way but using different driving style to ecourage ICE or EV to compare the data within the same labs around the track. Many different ways to use a controlled FLAT test track.

We really need to give Bob a hand in coordinating this event and trying to talk the plant into letting us use the track (as long as we don't interfear with the production of cars).

 

Yeah! My wife has 8 or 9 girlfriends in for a gathering every 3 or 4 months.

If I have to put up with 80's Big Hair women watching Duran Duran videos and getting drunk all weekend, then she can put up with a few Toyota Techno Buffs!

 

WOW...I'm not sure about the estrogen party (My wife would kill me if she read that LOL) The 80's music sounds good though. That's my era of music (30 something).

 

No way are any other men coming over when that is going on. Go find your own drunk women!!

 

Oh no I wasn't inviting myself I just know what you are talking about...my wife has those gatherings herself. In fact she had one last weekend. I was saying my wife would kill me if she heard me calling it an "estrogen party"

 

I just found an article in "Public Citizen News" about "Hot Fuel". I didn't realize that many (most) of the retail stations in the US warm their gas (diesel) so the fuel expands and the buyer gets less energy than at the specified 60° temperature. They figure that US customers are overcharged $2 billion a year by this. Canada oil companies monitor the temp so that they don't sell it at less than 60° and give their customers excess. I wonder how this figures into our FE figures.

 

Some planning comments:
Well, now that things are moving, here are some comments regarding what I think would be most relevant to the aim of this thread — namely, to see whether one can in practice better Toyota's FE by forcing extra pure-EV-mode operation. Bigsk8r, in your list of variables that might affect the TCH's performance, I don't think ANY of them would affect the DIFFERENCE between normal and forced-pure-EV-mode driving modalities. Only the ABSOLUTE FEs would be affected, not the FE difference between modalities. During my experiment, most variables were held sensibly constant. The only quantities that changed significantly (but not enough to worry me) were ambient temperature and fuel level. The temperature changed by only 3 degrees C (~6 degrees F) during the course of the test runs. The fuel used during the test runs was 11.1 L (~ 2.9 galUS). This means that the vehicle's mass changed by 8.2 kg (~18 lb) during the course of the experiments. This is small enough not to be significant.

However, the SOC display has only 8 bars. Each bar thus represents 12.5% of the NiMH battery's usable capacity. The possible SOC reading error is thus +/-6% worst-case, and this IS large enough to be potentially significant. One MUST ensure two things:
(a) that the vehicle is returned to its starting point (i.e., use a closed loop as the test circuit); and
(b) that the SOC is returned to its initial value, before taking fuel usage data in the pure-EV-driving mode;
in order to have a valid comparison. The SOC reading error might introduce greater variability than any of the other relevant factors. How do we handle this?

Let's quantify the effect of the seemingly small difference in my average speeds for the two different driving modalities — 58 km/h for forced-pure-EV modality versus a nominal 65 km/h for the normal-driving modality. Under the standard assumption that air resistance is proportional to the square of the vehicle's speed, the air resistance would have differed by a factor of (65/58)-squared = 1.256. This is a 26% increase at the higher speed that I adopted for normal-mode driving. This IS significant! That's why I recommended using a lower normal-driving speed of 58 km/h in any future comparisons.

Next, realize that it's the CHANGING of the vehicle's speed (i.e., any accelerations or decelerations) on a flat track that cause its kinetic energy to change, and so demand energy input (acceleration), or energy recovery (deceleration). Driving at as constant a speed as possible eliminates these effects as factors. This may be one reason why (as a number of people have commented in this Newsgroup) using the TCH's cruise control actually INCREASES their FE over what they get without it. As you can see from the instantaneous FE gauge, the worst readings are while accelerating, and so avoiding this as much as possible will help to optimize FE.

nash and scottzorch: I too have noticed a decided "gear shift"-like effect occurring in my TCH under conditions like those you mention. It's almost like a torque converter "locking up," only more so. My interpretation of what's going on is, however, quite different from yours. What I find consistently is that this effect occurs when my car FIRST reaches an ICE temperature ~60 degrees C (according to my ScanGaugeII — SG for short) while warming up (it's around 3 minutes after starting, and the temperature gauge has JUST reached its "normal" position, 1 division below half-scale), and while I am travelling at a CONSTANT speed of around 60-65 km/h (say ~40 mph). SG shows that the ICE load factor drops suddenly from ~85% to ~60%, the FE gauge shows that the FE changes simultaneously from ~10 L/100 km to ~5 L/100 km, and the ICE rpm drops from ~1750 to ~1250 at the same time (these are not precise numbers!). I attribute this to a change in Toyota's strategy at this point in the warm-up cycle. I suspect that they are either reducing the amount of battery charging, or using more MG2 assist from this point on than they have up to this point. I cannot substantiate this claim. But, if this is the effect that you are talking about, I think that my explanation is more likely to be correct than yours. I have not been aware of this effect occurring later, after the initial warm-up is over.

Stan