2013 Dodge Dart + Fiat 1.4t MultiAir

[NachtRitter]

Totally opposite for me... being heavier does not inherently make it a safer vehicle. I would much rather have properly designed lightweight vehicle than an improper designed (or even properly designed) heavy vehicle... I want to have the opportunity to avoid an accident altogether than have no choice but to wallow into one.

[Daox]

Unfortunately IIHS doesn't have crash safety ratings for the Dart yet. But, I'd put money down that the Dart isn't notably better in crash tests than most other cars in its class.

[Cd]

Originally Posted by Neen

A cd of .3 is fantastic for an "every-day man" car. It still has the functionality of pretty much any other car, allows for decent clearance and suspension travel and complies with fed bumper regulations. The Leaf has cd of .28 and is basically the most advanced mass production energy efficient vehicle.

.30 is horrible .
.28 for an electric car with no engine cooling needed and a full belly pan is even worse !

There are some pickup trucks with stock drag numbers close to .33 ( last generation Ford Lightning )

They aren't trying very hard.


And as a reminder, cars don't need to look like a Prius to have good aero.

Example being the Lexus LS430 at .25 Cd.

[v2squared]

Man that thing is almost as heavy as my 2012 Passat TDI, and has less room and no where near the mileage????

[NeilBlanchard]

I stand corrected on the Cd of the iQ. I was going on my memory of an old thread here on EM, that stated 0.299:

http://ecomodder.com/forum/showthrea...1-a-11816.html

The other cars I mentioned have better Cd than the Dart. I have ecomodded my Scion xA from 0.31 down to about 0.26-0.27, according to my coastdown test. I have done additional mods since then, but I had a badly dragging rear brake drum when I tried a second coastdown test. I know my car coasts very well.

If I can lower my drag by .04+, then so can Chrysler.

[ksa8907]

Originally Posted by Daox

Unfortunately IIHS doesn't have crash safety ratings for the Dart yet. But, I'd put money down that the Dart isn't notably better in crash tests than most other cars in its class.

Yeah, but their tests dont mimic the real world. The civic may have a 5 star rating when it hits a barrier, but what about a suburban traveling at the same speed? Small cars just dont have the same amount of crumple area and heavier vehicles typically fair better than lighter ones.

[NachtRitter]

Originally Posted by ksa8907

Yeah, but their tests dont mimic the real world. The civic may have a 5 star rating when it hits a barrier, but what about a suburban traveling at the same speed? Small cars just dont have the same amount of crumple area and heavier vehicles typically fair better than lighter ones.

Small cars don't need as much crumple area because they are smaller and can be more easily stopped with less crumple area ... Assuming the larger vehicle even has a crumple area to begin with (by that I mean an area that is actually designed to crumple in a collision, not just a larger distance between front bumper and driver which can't crumple), then that crumple area would have to be larger in order to be as effective as the smaller car's crumple area simply because the larger (heavier) vehicle takes more energy to stop. Good ol' physics!

So what about the suburban traveling at the same speed? 1) it's more difficult to control than the lighter, more nimble vehicle so it's more difficult to avoid the accident to begin with, 2) it would be more difficult to stop the greater mass after it collides with something (meaning more opportunity for something REALLY bad to happen, like a rollover), and 3) if it isn't designed to the same safety standards as the smaller car (anything heavier than 5,500lbs does not need to meet the stricter safety standards of vehicles under 5,500lbs, and a 2012 suburban is over 5,800lbs) then more of that impact energy gets transferred directly to the occupants. All of which means there is less chance for survival in the larger vehicle than the smaller one. Granted, there are exceptional cases where being in the larger vehicle might be a benefit, but looking at the odds I'd much rather bet on the lighter vehicle.

For the Dodge, if it is a heavier vehicle, then the crumple area (and other collision aspects) would have to be of a superior design compared to a similarly sized but lighter vehicle for the Dodge to be safer in either IIHS tests or the real world since it will take more energy to stop it ... and the handling would also need to be superior so that the average driver would have more of an opportunity to avoid the accident (either by simply slamming on the brakes or by doing a basic avoidance maneuver). I'm going to be pessimistic and guess that neither is true.

And for the rest of that heavier vehicle's life (when it's not getting into unavoidable accidents every other day), it has to schlepp around all that extra heft for no discernible benefit to the driver, the occupants, or the rest of the world... why?? Because of this silly "bigger is gooder" myth?? Will we ever learn??

[kah]

Smart car crash test

www.youtube.com/watch?v=n3bFhVvdlaI

The Dodge Dart is based on the beautiful Alfa Romeo Giulietta (Cd=0,31), so you could probably expect similar performance, FE and safety. Here's what fifth gear had to say about it

www.youtube.com/watch?v=cQjwvtAzgAk

[NeilBlanchard]

Heavy |=| Safe.

The only type of crash where weight "helps" -- if all else is equal -- is in a direct head-on crash.

A heavier vehicle has a lot more energy to slow down (i.e. braking takes longer), it is harder to turn to avoid an accident (i.e. it handles more sluggishly), and they require larger crumple zones. In accidents that only involve one vehicle, more weight always is a bad thing, if all else is equal. Greater weight often means a higher Cg, and vehicles like SUV's and vans rollover way too often. A large portion of SUV accidents involve rollovers.

Direct head-on collisions are about 3% of all accidents, or maybe even less than that.

Back on topic: I'm glad that Chrysler has chosen to at least enter a car in the competition for high(er) mileage 4-5 seat cars. I'm glad they are at least adding some aerodynamic features. The Fiat engine is a really good one. I like the Dart heritage and the name. I think that like GM and Ford and Honda and Nissan and Chrysler need to join with Toyota in offering a car or cars that get >50MPG and have Cd <0.25.

Who is going to be the first to sell a car with a Cd equal to or better than the Audi A2 or the GM EV1? We need lots of cars that have Cd's <0.20. If they could do this back in the 1930's (Schlörwagen "Pillbug" and Maybach Stromlinienkarosserie in particular!) then we certainly can do it now.

[ksa8907]

In response to avoiding accidents, ive driven my 3500lbs intrepid for almost 7 years and have never had a problem manuevering. I worry more about the incompetant part of the driving population. Call me old fashioned but a little more expense in fuel is worth the safety of a larger vehicle. Im not saying all large vehicles are safe and small are unsafe, im just putting my bet with our pacifica. 20mpg on a good day but theres nothing i feel safer in.