Ford Just Unveiled A Fusion That Weighs As Little As A Fiesta
 

Impressive.
http://jalopnik.com/ford-just-unveil...-fi-1585576176
[ame="https://www.youtube.com/watch?v=fqFgj6zfHso"]Ford Unveils Ultra-Lightweight Concept Car - YouTube[/ame]

The only thing here i don't see going into a production car is those skinny tires, that's...a bit much.

Out of a carbon fiber oil pan, carbon fiber wheels, composite springs, aluminum brake rotor and the thing that strikes you as something that wont make it to production is the fact it has skinny tires?

This is nothing different than the first gen Insight. A design experiment to see exactly how far they can push the envelop and make a full size vehicle that actually gets respectable fuel mileage. Honestly I hope all these techs make it to market as its going to have effects in the sports car world as well.

skinny tires = less rolling resistance :P

Of course, the 4C has a carbon fiber chassis and that's coming to the states.

If my memory serves me right, there was a time where cars has composite leaf springs, no?

I had a good friend who works a Nissan dealership, the most common complaint of people not wanting to buy a Nissan Versa is that the tires look skinny and dangerous. I think they
changed them now.

Ford has taken from their concepts and put the tech and design into future production cars.

Also less air resistance :)

Also better to slice pizza with.

Its a bit unfair to compare a $70,000 car to a $20,000 commuter sedan no? Mclaren and Koenigsegg also make heavy use of carbon fiber but that doesn't mean its ready for use on a mass produced car.

The corvette uses composite leaf springs.

Basically I was saying that skinny tires play a huge role in fuel economy. Look at the first generation Honda Insight, or the VW XL1, or Honda CRX Vf. All of these cars have super skinny tires for one reason, fuel economy. Obviously this car is a experiment in how high they can push the technology envelop to develop a super high FE vehicle. Super skinny tires seems like a much more realistic feature to bring to a mass produced car like that than carbon fiber wheels.

Actually skinny tires can have more rolling resistance since the tread gets stretched around more from the higher loads, but the decrease in air resistance is huge. Ever wonder why supercars with their carefully formed bodies have huge amounts of drag even in the absence of wings?

They're talking about a 2,600 lb Fusion.

Give me a 2,000 lb Fiesta ST!

:drool:

Edit: Scratch that, Fusion weighed ~3,600 lbs, Fiesta weighs about 2,600. There's no way they didn't sacrifice the interior to meet that, dropping 1,000 lbs is absurd unless they readily admit they no longer meet crash safety standards.

The frontal area of the vehicles body obviously plays a much larger role in the Cd of the vehicle than the tires do. Skinny tires don't have more rolling resistance if the load rating of the tires is balanced to the vehicle its used on.

The vehicle's body is much bigger than the tires, but the tires have much higher Cd than the rest of the body. If you don't think tires and wheels add a lot of drag, you might want to think again. Adding 1 inch to the width of the tires between Porsche S and non-S Carrera models adds 4% more drag to the whole car. That's only a frontal area increase of 0.5%. A perfectly streamlined car body with no wheels would have less than 0.1 Cd, but perfectly streamlined cars with wheels have achieved at best 2 times that, and these are skinnier tires than a stock Prius has.

The hysteresis in the tires will be higher if the tire compound is the same and the tread thickness/pattern is the same. Thinner tread like on a bicycle will decrease your rolling resistance, but car tires don't come much thinner from the factory.

Of course tires add to drag, which is exactly why I said skinny tires were used not only for reduction in in drag but rolling resistance, but a vehicles bodys Cd is different the the rolling resistance of the tires. Obviously the resistance to rolling adds to the resistance the vehicle needs to overcome to achieve forward motion. Tread compounds can be optimized from fuel economy as opposed to traction or cornering performance, which is what you typically find in LRR tires. I think its also important to consider the fact that LRR is a subjective term and its dependent on the tire size. There's been several cars that reached lower than .20 Cd. albet only two really made it to "production".

I imagine there are not many people who are active on this forum have a firm grasp of what it takes/have experience with high fuel economy driving. Ford producing a car like this not only makes it easier to achieve high FE in the hand of the average driver, the trickle down effect it has on the rest of the automotive industry is a good thing. Who would argue with getting carbon fiber wheels or a carbon fiber chassis standard on their BRZ? These things are out of reach currently due to the cost associated with fuel scale production of carbon fiber parts but hopefully in the not to distant future we'll see this making it down to the realm of normal cars.

,I'm just saying, the wheels/tires account for about 0.1 of the Cd of the whole car, sometimes more, and it's not correct to say that the body has a "much bigger effect".

Yes tread compounds can be optimized but if you make the tire bigger, the contact patch will experience less hysteresis loss on the same compound. Of course the extra weight and drag negate the slight benefit.

Aluminum rotor is a little questionable but probably okay for an everyday car. On the track though you'd soften them and rip them to shreds pretty fast. Probably better to stick with cast iron, might be possible to do aluminum cooling fins on cast iron disks with supporting steel core.

I'd really rather not argue about something as trivial as this but you are incorrect. Rolling resistance is a completely separate form of resistance from coefficient of drag and you are off by quite a bit on the amount of resistance tires actually have. Rolling resistance accounts for roughly 0.01 for a normal tire on concrete. LRR tires are less than that figure. Hypermilers for years have been jacking up their tire pressures to get that figure even lower.

Check out http://en.wikipedia.org/wiki/Rolling...cient_examples and http://ecomodder.com/forum/showthrea...ower-6341.html if you need further proof.