C&D: Drag Queens: Five slippery cars enter a wind tunnel; one slinks out a winner

Insight G1 would still win despite being designed almost 20 years ago. It has the lowest drag of any car in the used market. It has 1.0 square feet less drag area. (Note: Volkswagen's 120mpg XL1 has the absolute lowest drag, but it hasn't gone on sale yet.)

 

I still really like the look of that car. I think they could release it again today with almost no styling changes, and it would hold up very well.

I would be very tempted to buy one if they did.

 

Here's to hoping the engineers are allowed to refine the shape for gen 4, rather than have stylists design something that LOOKs swoopy.

 

We kind of knew about the leaf. The big surprise was the mercedes cla, it is much worse than mercedes led us to believe, but perhaps the US version is missing some key aero from the european version.

The fussion hybrid and accord hybrid are probably getting too close in terms of mpg for toyota to sit on the efficiency. The roomers were slightly different shap, probably in the front, and lower frontal area. It still is likely to have a family resemblance

The last really cool design studies were in the 1980s spured by the oil lines in the 1970s. The ford probe V was 1985 with a tiny fronal area, seating 4 and cd of under 0.14, and the vw xl1 appears to follow that look. You can't really get close in a tall car like the prius.


Really with the prius - taller than average car and seating 5 with cargo room, c=0.24 with smaller frontal area is about what we can expect.

 

I thought the EV1 did better. No?

 

Its right there in the article. I added the 1985 4 seat ford probe V at cd = 0.137. Ev1 and vw xl1 probably learned something from that design exhibition.

Tesla 6.2 drag feet currently for sale 5+2 seats

The rest are all 2 seaters.
Insight 6.0 drag feet sold in the past
EV1 4.2 drag feet (cd-0.21) leased and crushed, never sold
XL1 3.1 drag feet (cd-0.19) not yet for sale, won't likely be sold in US for emissions reasons

 

Here's a list from ecomodder:
Vehicle Coefficient of Drag List - EcoModder

CdA:
Leaf: 6.94
Volt: 6.51
G3 Prius: 5.84
G1 Insight: 5.0
EV1: 3.96

 

Making a small car may be a good idea, but it is hardly a futuristic design. In fact the CD of 0.3 is pretty so-so, a full 15% worse than the Prius.

 

the bad news is that it's going to be very difficult for toyota to pick up mpg's through aerodynamic improvement.

 

I think part of the point of the article is that the wind tunnels these companies use very quite a bit, so the numbers in say ecoModder have errors in them. The car and driver numbers at least use the same wind tunnel procedures for all the new cars. The volt and tesla S had numbers consistant with their wind tunnels, but the leaf and cla had a lot more drag, when measured in the same way as the other cars.

 

There's plenty of room there at the bottom. Cutting the CD number in half isn't impossible.

 

The article listed the wrong number for the 2000 insight. It has a Cd of 0.25 per Honda specs (which multiplies to a drag area of 5.0 cu.ft). That number also matches EcoModder's drag calculation of 5.0. It also means the insight only needs 11 horsepower to move 70 miles/hour.

Oh cool! Where can I buy an EV1 on the used market?

 

You could steal one from a museum and transplant the guts from a Chevy Spark EV. Will probably do better than any EV out there now except for Tesla. [That in itself is sad for the state of EV]

 

A day which will live in infamy...

 

Toyota can reduced aero-drag and improve warm-up very easily:

When I performed the same test on our 2010 Prius, we got a 2 MPG improvement, ~4%.

There should be no frontal air inlets but an articulating, scoop that lowers to pull in cooling air as needed backed up by the radiator fans.

There are more tricks including articulating air dams on the front and side that descend at speeds above 45 mph. Also, wheel well covers at high speed and/or moon caps.

Bob Wilson

 

Shuttered radiator vents, retractable side mirrors or cameras. more prone seating arrangement to lower roof line.

 

insight currently has the record for cars that have been sold in the US (not leased).

GM did gut the cars and give them to any university that wanted one. Wisconsin students put one back together with Ford Ranger Batteries (also donated) and some donated electronics.
http://vehicle.slc.engr.wisc.edu/?page_id=241

People forget pesky things like crash tests. The ev1 could pass the one made for it in its day, but it got 3 out of 5 on the frontal test. I doubt it would even be street legal on today's much harder tests.

For many people the spark ev or fiat 500e are better than the ev1 for compliance cars. They just don't look as cool, but they are safer, less expensive, and more practical. Sure the tesla S 60kwh and 80kwh, roadster, and tesla partnered rav4 ev are the only cars with more range, but thoese are 3 models, with more coming.

For aero, bmw and vw are the only companies with prototypes as slippery as the ev1. vw's is a phev diesel 2 seater that will likely cost more than a tesla S and be sold only in europe. BMW has an efficient dynamics prototype, but are selling the much less slipery i8 and i3. The i3 other than looks, is a better car in about every way than the ev1, and likely costs bmw less than ev1 cost gm.

 

Here's hoping the G4 Prius engineers design something targeted for maximum efficiency, versatility and sales in the US. After all, isn't the best purpose to save the most resources (gas) possible?

 

Cheap, high tech, and appeals to everybody so long as they are American.

Glad your demands are reasonable.