4th generation coming 2015!

Could be lighter as long as it's a lower center of gravity. I believe it'll have better handling and better acceleration. Have we beat the gen3 speculation thread yet?

 

This is another area I know little about, but
Why does a Porsche (and race cars) have devices to exert down force. They have low weight, low center of gravity, but need the downward force to keep them on the road.

Light i great for a low speed town car, but at highway speeds, here in the west where the wind is frequently 30 and 40 mph, passing a truck would be terrifying

 

they are designed for 200 mph, which will cause the car to lift without them. the buying public simply enjoys paying for the thought that they could be driving lemans.

 

So you're all saying a Datsun 510 was terrifying to drive? Not likely. It was a hoot. And weighted right around 2000 lbs. Of course if they wanted to make them again now they'd have to add another 1000 lb to make them crash worthy.

Most cars have "upforce" in the rear at high speeds. Hence, in Europe, certain cars have spoilers that deploy when they speed up, and others just have them deployed all the time. This is to ensure they don't swap ends on the autobaun at 160 km/hr.

 

Indeed.

Over the last 15 years, I initially drove about 7500 miles per year, and now I drive about 10000 miles a year. During those 15 years, I've only owned Priuses.

 

You're assuming most people who buy a Prius buy it for the gas mileage alone.

That was just one of several reasons I bought mine. If it had not been a hybrid, I would still have bought it over any other car available at the time. A "crossover", in any form, is not a car that will interest me.

Oil, used as an energy source, is an evil thing. I'd love to use zero but BEVs aren't anywhere near ready for prime time (Tesla's are a good example) and no one has done a hydrogen vehicle correctly yet (including Toyota). The best alternative is to use as little oil as possible by driving less, driving efficiently, and driving an efficient car.

 

2016 Prius in Thailand?
SPIED: 2016 Toyota Prius caught testing in Thailand!

 

SPIED: 2016 Toyota Prius caught testing in Thailand!

 

And some have spoilers "borrowed" from another car

 

Composites ready for mass production of auto industry

(CFRTP) in Gen IV Prius?:


http://techon.nikkeibp.co.jp/JTR/PDF/sample/006CFRTP-0412Sample.pdf

 

Trrrraction!!!!! They need traction from the tires and LOTS of it. They are ripping so hard around those turns, need tire traction from extra downforce.

Those massive spoilers on top fuel dragsters add downforce. The rear tires are huge but can easily lose grip with a 10,000 HP nitro engine (that is what they estimate the top fuel cars put out these days. Not a typo, they say ten thousand HP.

 

Low rolling resistance tires + 40psi = less "grip" around corners!

 

bigger spoiler on gen IV.

 

BMW and Toyota exchanged some information, Toyota uses BMW diesels, wonder if they also exchanged info about CFRTP.

I don't see 20% lighter Prius as so preposterous thing, side wind is not a problem in a low profile Prius shaped car, but realistically I expect 10% lower weight. I didn't see much negativism about Mazda 3 or Golf that already weight 10% less than Prius.

 

A true "...leaf in the wind..." (not necesssarily a Nisson Leaf) ?

 

I said before, this is not a field that I have any knowledge, BUT

Does it not seem reasonable that a vehicle that touts fuel efficiency, would want to be as light as possible?
Does it not seem reasonable that at highway speeds , a car must put more weight on the road (cornering, braking and cross winds)?
Isn't that why some cars like the Porsche, deploy a deflector only at high speed?
Is that why the Prius is shaped the way it is (light weight, but at speed, puts more downward force from the wedge shape)?
Just curious.

 

Downforce of the current Prius is none, it actualy produces 17 pounds of lift at the back at 70 mph:
http://www.teslamotors.com/sites/default/files/blog_attachments/the-slipperiest-car-on-the-road.pdf

But then again 17 pounds is next to nothing.

 

As I said above. Almost all vehicles produce lift in the rear at higher speeds. If it's enough, it can unload the rear wheels. The Audi two seater (forget the model) lifted the rear wheels enough the car would loose control on the autobaun in Germany. Hence, in Europe, it was mandated that it have a "spoiler" to reduce the rear lift. The "new Beetle" is the same. Audi added an automatic deploying spoiler (so it wouldn't detract from the "good looks" I guess). It had a "cool factor" as well. The "Beetle" has a fixed spoiler.
Most of the aero effects used simply introduce turbulence to defeat the lift. Proper wings to produce downforce don't work unless you're going very fast, faster than permitted in North America. Most race cars start to notice the aero effects above 80 MPH, and they become effective above 100 MPH.
Remember the Toyota Supra? It had a rear wing, which produced about 40 lbs of downforce at 100 MPH. I remember that from someone who owned one bragging about it.

For reference, an F1 car produces so much downforce at speed (250-300 km/hr) it -could- drive on the underside of an overpass.

You won't get that on any street legal car. You can't go fast enough. It also causes a lot of drag, which ruins mileage.

Finally, I learned with my 1993 Mazda RX-7 that the rear wing actually had only one function. It impeded the view when backing up.

 

Thank you GasperG and David Beale. So much for that explanation of the Prius wedge shape

 

FWIW, the "slipperiest" shape is one that produces neither "lift" nor "down force" whatsoever so that it yields the lowest drag coefficient.

Front-end lift unloads the front tyres reducing steering control. Rear-end lift unloads the rear driven tyres reducing power delivery to the road. And, both are dangerous at racing speeds.