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drees said:
evnow said:
A 10% weight increase will roughly decrease efficiency by 5% (don't have link).
Impossible to make generalizations like that without knowing the drive cycle...

In the city weight can make a big difference. On the highway, it can be nearly negligible.


On hills it's a killer.
 
EVDRIVER said:
On hills it's a killer.

I understand that you're against weight - and agree. And yet, if we take a Leaf that can run 100 miles and THEN add 300 lbs, there's going to be a performance hit. But if we take a Leaf at it's weight and 100 mile range, and put it along side the Focus and it's 100 mile range, then the weights don't seem that significant at that point.

Sure - more weight means more structure and more battery and more power and larger motor, I get the gist of the design spiral and the desire to 'add lightness'. But is it really accurate to take two fully developed cars with apparently similar performance and single out weight?

What am I missing, EVD?
 
drees said:
evnow said:
A 10% weight increase will roughly decrease efficiency by 5% (don't have link).
Impossible to make generalizations like that without knowing the drive cycle...

In the city weight can make a big difference. On the highway, it can be nearly negligible.
True. But this is to keep things in perspective. A 10% weight increase will not decrease the range by 50% for sure.

Anyway, when EPA / Ford publishes some range info we will know.
 
AndyH said:
EVDRIVER said:
On hills it's a killer.

I understand that you're against weight - and agree. And yet, if we take a Leaf that can run 100 miles and THEN add 300 lbs, there's going to be a performance hit. But if we take a Leaf at it's weight and 100 mile range, and put it along side the Focus and it's 100 mile range, then the weights don't seem that significant at that point.

Sure - more weight means more structure and more battery and more power and larger motor, I get the gist of the design spiral and the desire to 'add lightness'. But is it really accurate to take two fully developed cars with apparently similar performance and single out weight?

What am I missing, EVD?


This is a classic trap, comparing a heavy EV to a very heavy one. Besides aerodynamics weight is a HUGE factor in efficiency. Anyone wonder why all the major auto makers are racing to cut weight to make the future EPA numbers? In an EV this makes even more of an impact. If you drive in an EV with a respectable weight of say 2700 lbs and watch actual kw usage and then add weight in 100 lb increments under the same conditions you will become very aware of the impact in efficiency and in your foot. Put a hill in the mix and is exponential. This and aerodynamics is what it is all about in an proper Ev design. The pack is a separate issue on its own, just look at why so many converters use the lowest weight car available, why Tesla builds the way it does.

An EV is FAR more sensitive to fluctuations in efficiency than an ICE because of the available energy storage density between gas and our present battery tech. This is only evident when people go up hills or see detailed consumption data while driving and when they see the difference in weight variables. The mods people made to cars for aero gains make even greater strides on an EV. Even the viscosity of the gear oil in an EV can make an impact on range, also the cut on the gears. The leaf gears are set for noise and compromise on efficiency, these things do make a difference particularly when added together. If you own a compact car, add 300 lbs and see how it does up hills and how the economy changes while driving the same on hills and on the city, the rules don't change because the car is already heavy.
 
But low weight or very low cd don't come free. There are always compromises to be made.
 
EVDRIVER said:
Put a hill in the mix and is exponential.

No, linear:

Code:
y = mx + b

So just drive as is up the hill at a fixed speed and measure kW; then add 300 and measure the same run's kW. y is your kW, x is your weight (say x=0 corresponds to curb weight) and compute b and m; you then know what any weight increase will do because w/o acceleration, the penalty's linear.

Code:
U = mass * g * x * sin(theta)
 
evnow said:
ps : Timehorse, do you have links to how EPA calculates EV range ? I know they are trying to change stuff - not sure what exact method they used.

For what it's worth, I put in a FOIA request for Leaf/Volt testing details just before Christmas. I got an e-mail on Dec 23rd confirming they'd received it but haven't heard anything else yet. Part of the request was the specifics on the test protocol used. Naturally I plan to make a topic about it once I get an answer... until then I decided it's not worth getting in an argument about.

=Smidge=
 
I like the looks of the Ford, particularly the interior, but I have to say that the placement of the battery pack really seems to encroach on usable storage. I guess this is to be expected on a conversion. Still, kudos to Ford for coming into the pure EV game. If I still don't have my LEAF this time next year, the Focus might make the shopping list if just for the 6.6kw charging.
 
LBCev said:
If I still don't have my LEAF this time next year, the Focus might make the shopping list if just for the 6.6kw charging.
Yes, the slow rollout of Leaf gives an opening for Ford in non rollout states. Still, a lot depends on the price. Huffpo reports that Ford people are saying it will be priced lower than Volt.
 
Some rolling video. And some shots of the app on Samsung Focus. Hmmm.

Front still looks odd - but better than some shots. I like rest of the car design.

[youtube]http://www.youtube.com/watch?v=mkBQmQ2F54c[/youtube]
 
I like the looks very much, even the front end. Looks smooth and I do like the Aston resemblance.

But I'm not excited because of the compromises brought about by the conversion nature of this beast, meaning weight, weight distribution and interior space efficiency. Also, the fact that the project was apparently farmed out to a partner instead of being done completely in house would give me pause.

Very interested to see the price, though.

Thanks for the rolling video, evnow. Video of a car moving always tells me a lot more about its styling than a static view.
 
Boomer23 said:
Very interested to see the price, though.
Me too! And more shots of the interior.

I have to say it's not a bad looking car, and if priced competitively with the Leaf could give it a run for its money. Especially if Nissan doesn't step up its production numbers. Interesting times!
 
By the way, the under-hood shot looks a bit like there is an ICE engine in there, don't you think?

Nissan took some flack for trying too hard to make the LEAF as "normal-looking" as possible, even to the extent of making the inverter look like an engine cover from an ICE car. Looks like Ford is taking a similar tack.
 
Plug in Cars review, has some nice pictures of the dashboard

http://www.plugincars.com/ford-focus-electric/review
 
evnow said:
LBCev said:
If I still don't have my LEAF this time next year, the Focus might make the shopping list if just for the 6.6kw charging.
Yes, the slow rollout of Leaf gives an opening for Ford in non rollout states. Still, a lot depends on the price. Huffpo reports that Ford people are saying it will be priced lower than Volt.

Lower than the Volt could be 40K...I'm guessing it will be around $38K, which is too much compared to the LEAF.
 
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