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Old 07-11-2011, 07:54 PM   #108 (permalink)
bwilson4web
Engineering first
 
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Join Date: Mar 2009
Location: Huntsville, AL
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17 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

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Hi folks,
Quote:
Originally Posted by IamIan View Post
. . .
Nothing new there.

Except more information about vehicles that in a specific context are more efficient than the Prius... perhaps you should have read it closer.

Prius with 5 seats even at ~50 MPG = ~250 passenger MPG

= more efficient than Prius.

= also more efficient than Prius.

= more efficient than Prius.... a short ton of people is a lot of people... at even 100kg per person ... that is 9 people * 436 = 3,924 passenger miles per gallon ... for a 5 seat Prius to beat that ... means the Prius with 5 passengers in it needs to achieve better than ~784 MPG ... sorry dude ... I know you are pro Prius . . .
If you agree with those citations, so too do I. <GRINS> It is a fundamental definition of efficiency. You might not like how we got here but I'm very happy with it . . . what ever it takes to swing a 'clue by four.'

BTW, I'm only 'pro' engineering and accuracy. If it happens to be the Prius, good. But I also like the latest Honda Insight and Ford is doing some notable work. Heck, even GM s*ck's less. What I'm seeing in the 2011 and 2012 models is radically different from what we saw before. By no means perfect, it raises the bar.

Quote:
Originally Posted by dcb View Post
. . . This forum is about modding for economy/ecology, not worshipping priuses that have no mods.
Only my wife's Prius is stock since it is still under warranty. My NHW11 commuting car continues to be my test item:
  • oversized front tires - reduced rolling drag and improved steering
  • thinner transaxle lubricant - reduced rolling resistance
  • engine oil test - boron CLS, not effective, interesting 4-6 micron particle drag effects
  • four-wheel alignment - reduced tire wear
  • NHW20 modules - lower internal resistance
  • house AC power from Prius - 1kW, 12V DC system today, larger is planned
  • exploiting early warm-up, EV mode - ability to reach 35 mph by exploiting Prius control law
  • thermistor hack - retrofits NHW20 warm-up profile into NHW11 model
  • 2" receiver hitch and trailer - for over-sized loads
  • backup camera, GPS and rear-view mirror - safety when backing into a spot to exploit the warm-up EV mode
So yes I do experiment with my NHW11 and we can find plenty of threads that touch on similar experiments with other cars. As you might have noticed, I prefer to measure what is going on, all aspects of what is going on, based upon fundamental laws of physics and engineering. My only competition is the 2nd Law even though I know it always wins.

Going back to my wife's stock Prius, I am conducting an accelerated, transaxle oil change program. It was changed at 5,000 miles and soon will be changed at 20,000 miles. Based upon those oil test results, I may elect to have it changed at 30, 40, 50 or 60,000 miles. This is a much faster change rate than the normal Toyota service intervals. It is less of a modification as an experiment to determine if there is merit in a faster than recommended, transaxle oil change cycle.

Quote:
Originally Posted by Frank Lee View Post
Bob, you do realize that this is getting ridiculous.
No better nor worse than many other discussions. But yes, I do enjoy having fun with those who take what we do a little too seriously or take cheap shots. Poking fun is a two-way street, right?

Tonight, once it cools down a bit, I'll take an oscope out and probe an interesting signal that I've not been able to decode, yet. Once figured out, we'll know if two other Prius with a work-around, interlock problem can be made to work 'normally' instead of showing a master-fault that requires a double-start, workaround. It potentially returns two, 50 MPG vehicles to service not unlike some of the Insight threads have been reporting.

Also today, I reinstalled the Graham miniscanner and programmed it to record:
  • MG1 torque - that is 28% of the ICE torque and used to calculate energy flow
  • MG2 torque - used to calculate MG2 energy flow
  • ICE MAF flow - used to calculate fuel flow to calculate BSFC in operation and indicated and true MPG
  • MG1 rpm - used to calculate MG1 power
  • MG2 rpm - used to calculate MG2 power and in combination with MG1 rpm, the ICE rpm
  • traction battery current - used to calculate traction battery energy flow
  • parallel GPS tracking - recording true velocity and altitude, total mechanical energy
So with this data we'll be able to measure, not speculate or poorly quote others who should have known better. We'll have a 'teachable moment' which sad to say is not always a 'learning' moment.

Bob Wilson
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2019 Tesla Model 3 Std. Range Plus - 215 mi EV
2017 BMW i3-REx - 106 mi EV, 88 mi mid-grade
Retired engineer, Huntsville, AL
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