panamamike
Posts: 121
Joined: Sat Jan 25, 2020 10:21 am

Re: Using range extender only for electric charge

Wed Feb 12, 2020 1:00 pm

alohart wrote:
Wed Feb 12, 2020 12:11 pm
panamamike wrote:
Wed Feb 12, 2020 10:36 am
I wonder how they calculated the generator efficiency to be 94% giving 23.3kW.
I interpreted 94% to be the efficiency of the electric side only (i.e., the generator, rectifier, battery cells, etc.).
I'm interested in the optimal gas to electricity generation efficiency. Would it be possible to get better than 40 mpg from the REX.

alohart
Posts: 2401
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Using range extender only for electric charge

Wed Feb 12, 2020 3:20 pm

panamamike wrote:
Wed Feb 12, 2020 1:00 pm
I'm interested in the optimal gas to electricity generation efficiency. Would it be possible to get better than 40 mpg from the REX.
Based on what I've read (we have a BEV), under ideal driving conditions, 40 mpg would be near the top of the efficiency range reported. 30 - 40 mpg seems to be typical. Definitely less efficient than a Prius or other efficient gasoline-electric parallel hybrids. The series hybrid (e.g., i3 REx) process of converting chemical energy into electrical energy and then into mechanical energy is less efficient that the parallel hybrid (e.g., Prius) process of converting chemical energy directly into mechanical energy.
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

Johansensj013
Posts: 1
Joined: Fri Jun 18, 2021 10:20 pm

Re: Using range extender only for electric charge

Fri Jun 18, 2021 10:35 pm

Hello, I know it has been a while since you posted your question about the i3 max mpg using range extender. I can definately get over 40mpg. I routinely get 120 miles from 2.4 gallons. That would be 50 mpg. To get this i have to drive around 40mph for top speed and ease into starts and never stop fast or use brakes. This is also only achieved by using zero accessories in the car. No ac, heat, headlights, etc. I have also gotten more than 50k miles out of a set of tires. But again, this was a lot of 40-50 mph driveing and an alignment, while still within oem specs. more for rolling than safety/controlability. Seriously, the factory allignment is terrible on this car!

alohart
Posts: 2401
Joined: Sat Nov 01, 2014 7:36 pm
Location: Honolulu, HI

Re: Using range extender only for electric charge

Fri Jun 18, 2021 11:50 pm

Johansensj013 wrote:
Fri Jun 18, 2021 10:35 pm
But again, this was a lot of 40-50 mph driveing and an alignment, while still within oem specs. more for rolling than safety/controlability. Seriously, the factory allignment is terrible on this car!
What alignment specs do you prefer? Did you set the rear camber to the minimum negative camber and near 0º toe for front and rear?
Aloha,
Art

2014 BMW i3 Arravani Grey, Giga World, Tech + Driving Assist, Parking Assist, DC Fast Charging, JuiceBox EVSE

Obioban
Posts: 100
Joined: Wed May 22, 2019 6:16 am

Re: Using range extender only for electric charge

Thu Jul 08, 2021 10:51 am

Johansensj013 wrote:
Fri Jun 18, 2021 10:35 pm
Hello, I know it has been a while since you posted your question about the i3 max mpg using range extender. I can definately get over 40mpg. I routinely get 120 miles from 2.4 gallons. That would be 50 mpg. To get this i have to drive around 40mph for top speed and ease into starts and never stop fast or use brakes. This is also only achieved by using zero accessories in the car. No ac, heat, headlights, etc. I have also gotten more than 50k miles out of a set of tires. But again, this was a lot of 40-50 mph driveing and an alignment, while still within oem specs. more for rolling than safety/controlability. Seriously, the factory allignment is terrible on this car!
What a miserable way to live.

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