Ask Tom........

[TomMoloughney]

I'm sure I read somewhere the i3 has a drag coefficient of 0.28 ....I'm not sure if they said it was the lowest cd of a production BMW ... so lower than the ActiveE possibly.

I have seen that as a guess in different places Parker. However the official spec has not been announced yet, I am certain of that

 

[ChrisC]

I'm sure I read somewhere the i3 has a drag coefficient of 0.28 ....I'm not sure if they said it was the lowest cd of a production BMW ... so lower than the ActiveE possibly.

With the specs now out, we know the asnwer: it depends. The drag is slightly worse if you get the REx option, presumably because of the air flow disruptions by intake, exhaust and cooling flow.

Pure EV: Cd = 0.29
EV+REx: Cd = 0.30

Not surprising for that boxy shape.

http://insideevs.com/bmw-i3-range-extender-to-offer-up-to-87-more-miles-decreases-performance/

 

[Parker]

Volkswagen Golf VII BlueMotion has drag coefficient of 0.274

I'm surprised the i3 isn't lower. The Mk7 Golf isn't exactly slippery.

I think Tom is right high speed cruising will take a big toll.

 

[TomMoloughney]

Volkswagen Golf VII BlueMotion has drag coefficient of 0.274

I'm surprised the i3 isn't lower. The Mk7 Golf isn't exactly slippery.

I think Tom is right high speed cruising will take a big toll.

Yes, I was hoping for .27-.28 so it's a little higher than that. I always knew it would be much more efficient driving on secondary roads at slower speeds than on the highway. I'll have to see how the highway range is once I drive it though. That's really the true test for me.

 

[Mike74jcw]

Anyone have details regarding the sunroof? It appears to be one panel with 2 see-thru sections (driver and passenger) split with a roof support running down the middle. Will it open or merely be there to allow light into the cabin? Thanks in advance!

 

[gaz26]

Anyone have details regarding the sunroof? It appears to be one panel with 2 see-thru sections (driver and passenger) split with a roof support running down the middle. Will it open or merely be there to allow light into the cabin? Thanks in advance!

Sat in the car tonight and from what I could see its exactly as you describe in the first part of your question and yes it opens.

 

[TomMoloughney]

Anyone have details regarding the sunroof? It appears to be one panel with 2 see-thru sections (driver and passenger) split with a roof support running down the middle. Will it open or merely be there to allow light into the cabin? Thanks in advance!

It opens and slides back. I don't have a picture of it completely open though

 

[gaz26]

Hi Tom

Do you know if the i3 and wall box will allow you to power your home?? Recall people have been working on this technology I guess they get you to charge on low peak and upload from the car when power demand high??

 

[TomMoloughney]

Hi Tom

Do you know if the i3 and wall box will allow you to power your home?? Recall people have been working on this technology I guess they get you to charge on low peak and upload from the car when power demand high??

I know BMW has been working with this but no I do not believe it can. Nothing was said about this and I'm sure it would have been if it would have that capability. Manufacturers are reluctant to do this because of battery warranties. If you were to take this to the extreme and use the car battery all the time to power your house by drawing energy somewhere else - like a free public charger and then when you get home run your house off it every day, you will overtax the battery and likely wear it out long before your warrant is up and the manufacturer will have to replace it under warranty. I know this is an extreme example, but the battery is the most expensive component of the car and the car companies don't want to warranty it so you can use it for other purposes than driving your car. The added use will shorten the live . It's the same issue with Vehicle to Grid technology. If you are using your battery to help the utilities manage thier loads then the manufacturers are going to ask the utilities to pay to offset the cost of the batteries that wear out prematurely. It's a slippery slope.