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bwilson4web · 05-19-2010, 09:06 AM

Hi,

Auto Enginuity is a 'good news' 'bad news' system:

reports NHW11 codes
reports byte size engineering data OK
mixed results on 16 bit sized metrics
terrible results on longer data values
ZVW30 is still in 'generic' mode

However, I found the 'generic' ZVW30 data appears to be useful but their "Speed Tracer" seems to have a problem when calculating MPG:

These were two runs, same route, opposite directions. The obvious problem is it shows MPG going down, not up, when the Prius decelerates. The Prius shuts down the gas engine so there should be a brief peak of MPG when coming to a stop. So I decided to work from the raw engineering data:

The data elements are:

Coolant temperature - values on the right axis
Engine rpm - values on the left axis
Vehicle speed - values on the right axis
MAF airflow - values on the right axis. By using the 14 to 1 ratio, the fuel consumption can be calculated.
Commanded EGR settings - the values are on the right axis
Catalytic converter temperature - values are on the left axis. However, the 'cold' temperature' before the engine ran were abnormally high. I had to substitute the ICE coolant temperature for the first seconds of data.

These data points look right and match how we know the Prius works. But there were details not seen before:

Key elements are:

engine runs at a flat-line speed - until the engine coolant reaches at least 60C, the engine runs at a steady speed. Not tested, yet, is whether or not shifting into "N" reduces ICE fuel consumption.
Exhaust Gas Recirculation - unexpected, it runs any time the ICE is generating traction power and the coolant is over 70C. I was under the impression this happened only at high power settings but obviously it is diluting the fuel-air charge even at low power settings.

One thing is it looks like I can use Auto Enginuity to remap MPG vs MPH. Unlike my earlier benchmarks, the Auto Enginuity data significantly reduces the duration of each test. Combined with GPS tracking data, a total energy picture should develop.

Bob Wilson

05-19-2010, 09:06 AM	#1 (permalink)
bwilson4web Engineering first Join Date: Mar 2009 Location: Huntsville, AL Posts: 843 17 i3-REx - '14 BMW i3-REx Last 3: 45.67 mpg (US) Blue Bob's - '19 Tesla Std Rng Plus Thanks: 94 Thanked 246 Times in 157 Posts	Auto Enginuity and ZVW30 Prius Hi, Auto Enginuity is a 'good news' 'bad news' system: reports NHW11 codes reports byte size engineering data OK mixed results on 16 bit sized metrics terrible results on longer data values ZVW30 is still in 'generic' mode However, I found the 'generic' ZVW30 data appears to be useful but their "Speed Tracer" seems to have a problem when calculating MPG: These were two runs, same route, opposite directions. The obvious problem is it shows MPG going down, not up, when the Prius decelerates. The Prius shuts down the gas engine so there should be a brief peak of MPG when coming to a stop. So I decided to work from the raw engineering data: The data elements are: Coolant temperature - values on the right axis Engine rpm - values on the left axis Vehicle speed - values on the right axis MAF airflow - values on the right axis. By using the 14 to 1 ratio, the fuel consumption can be calculated. Commanded EGR settings - the values are on the right axis Catalytic converter temperature - values are on the left axis. However, the 'cold' temperature' before the engine ran were abnormally high. I had to substitute the ICE coolant temperature for the first seconds of data. These data points look right and match how we know the Prius works. But there were details not seen before: Key elements are: engine runs at a flat-line speed - until the engine coolant reaches at least 60C, the engine runs at a steady speed. Not tested, yet, is whether or not shifting into "N" reduces ICE fuel consumption. Exhaust Gas Recirculation - unexpected, it runs any time the ICE is generating traction power and the coolant is over 70C. I was under the impression this happened only at high power settings but obviously it is diluting the fuel-air charge even at low power settings. One thing is it looks like I can use Auto Enginuity to remap MPG vs MPH. Unlike my earlier benchmarks, the Auto Enginuity data significantly reduces the duration of each test. Combined with GPS tracking data, a total energy picture should develop. Bob Wilson __________________ 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 Last edited by bwilson4web; 05-19-2010 at 12:48 PM..