Stop and go City driving V steady state City driving

[aerostealth]

https://youtu.be/bhB-3-cNH_w

On Saturday I did a mpg test on our EV on a 4.8 mile circuit of highway set up for 40 mph with no stops. I had a turn around that could be managed with out stops. I did the test without stopping then I did the same circuit with six stops using a timer to simulate six 30 second stops for lights. The results were startling with 175 mpg-e versus 143 mpg-e for stop and go driving.

The next day I repeated the test using out Ford F-150 and netted even more amazing results. 26.7 mpg v 17.2 mpg. I converted this data into watt hours per mile just so people could compare the two power train types. I did make one mistake in the video reporting a 109 mpg-e figure which was for the vehicle doing 55 mph, not 40 mph, but otherwise the video is good, and wasn't worth re-shooting.

These results show in this instance a 22% increase in energy consumption for stop and go driving over steady state driving in my EV while a 55% increase is shown for a IC Engine powered vehicle.

[California98Civic]

Interesting results. Confirms what we already thought, which is also useful. I guess the ICE is even more inefficient (compared to an EV) on acceleration than in cruise. That makes sense because under higher load everything gets hotter, wasting more fuel as heat. Maybe that magnifies the normal differences in efficiency.

[jjackstone]

Additionally the ICE vehicle is burning fuel while stopped unless of course it has stop-start technology.
JJ

[aerohead]

Originally Posted by California98Civic

Interesting results. Confirms what we already thought, which is also useful. I guess the ICE is even more inefficient (compared to an EV) on acceleration than in cruise. That makes sense because under higher load everything gets hotter, wasting more fuel as heat. Maybe that magnifies the normal differences in efficiency.

The BSFC for the ICE is around 3X higher than the BSFC-e of the electric. The late, Dr. Paul MacCready of AeroVironment ( originator of the GM Impact/ EV1), used to refer to ICE vehicles as 'blast-furnaces on wheels.'

[jakobnev]

These results show in this instance a 22% increase in energy consumption for stop and go driving over steady state driving in my EV while a 55% increase is shown for a IC Engine powered vehicle.

Driving the test route with a hybrid would be interesting.

[aerohead]

Originally Posted by jakobnev

Driving the test route with a hybrid would be interesting.

This is the reason hybrids came to be. Honda and Toyota actually took President Clinton / Gore serious when their White House got behind the Program for New Generation Vehicles ( PNGV).
The auto stop-start, electric acceleration engine assist, and regen were all part of the strategy to recover from the inefficiency of yields, stops, un-synchronized traffic lights, and gridlock.
In 1988, the Texas Governor's Office published the results of research on traffic light synchronization. For every $1 spent, consumers would get $62 back. That was no incentive for change though, in a political environment lubricated by oil lobbyist campaign financing, and federal and state fuel taxes. We got a war in Iraq instead.