Sunroof

<div class='quotetop'>QUOTE(carz10 @ May 6 2007, 10:20 AM) [snapback]436334[/snapback]</div>

Not an option and none available.

 

<div class='quotetop'>QUOTE(Duane @ May 6 2007, 10:29 AM) [snapback]436335[/snapback]</div>

The roof is not flat, it would be very hard to install with the ridges and slope to the roof.

 

Negatives: It would add weight, take away headroom, add cost, and add the possiblility of problems with leaks.

Positives: It would add a little ventilation at no aerodynamic cost. Could be a selling point for some people.

Just because the roof is not flat doen't mean you can't put in a sunroof. Mazda did on the 3rd gen RX-7 with a "double bubble" roof.

Ask Toyota marketing why it isn't available.

Probable answer - "You can't always get what you want, but you can get what you need."

 

<div class='quotetop'>QUOTE(David Beale @ May 6 2007, 10:59 AM) [snapback]436346[/snapback]</div>

There is an aerodynamic cost. On a slippery car like the Prius, it's probably much higher than most would be willing to pay.

Tom

 

<div class='quotetop'>QUOTE(qbee42 @ May 6 2007, 10:12 AM) [snapback]436356[/snapback]</div>

Yep. That's the reason why there's no sunroof option from the factory. I remember seeing a thread somewhere ( along time ago) about an aftermarket Prius sunroof.

 

Here is some info about a sunroof for a Prius

http://www.priusonline.com/viewtopic.php?t=6857

 

The aerodynamic cost of a sunroof is very small to zero. The reason is the air is forced upwards by the windshield and separates from the car body at the front of the roof. There is actually a slight vacuum there. Putting a sunroof there (tilting kind seems to cause the least disturbance) helps to fill this vacuum when it's open (air from inside the car fills it). The air reattaches at the rear of the roof but separates again at the rear window. Attach small strips to your car and have someone drive it and watch from another vehicle. Then come back and argue with me.

Just because the Prius has a good aerodynamic design doesn't mean it's perfect. It has to conform to "car shape" requirements.

 

I've found that I seem to always want a sun/moonroof in my car and then rarely ever use it ... little to none.

 

<div class='quotetop'>QUOTE(David Beale @ May 6 2007, 07:02 PM) [snapback]436521[/snapback]</div>

True, and just because a sunroof sits in a low pressure area, it isn't immune to the laws of aerodynamics. An open sunroof creates a cavity flow condition, which creates turbulence in the shear zone between the fast moving outside air and the slow moving cabin air. The turbulence creates drag by generating sound and heat. To avoid annoying turbulent sounds, most sunroof designs feature a pop up deflector to move the airflow above the cavity. This is done at the expense of increased drag, as compared to a smooth roof surface, but is preferable to having your eardrums pop out from the noise.

As one of the other posters suggested, weight in the roof is probably a bigger problem than aerodynamics, seeing that you can make a sunroof that closes fairly well.

There has been some interesting research in the area of reducing sunroof noise. Take a look at the following article: http://www.sciencedaily.com/releases/2006/...60224102913.htm

It starts like this:
Fighting Sound With Sound, New Modeling Technique Could Quiet Aircraft

Science Daily — Newly published research by a Princeton engineer suggests that understanding how air travels across the sunroof of a car may one day make jet engines less noisy.

Tom

 

I've found sunroofs work best for me (air flow with minimal noise) just tilting up the back. The anti-Prius (see below) sunroof can slide open (never use it except when parked so children can stand with their heads out the top of the vehicle - they seem to get a great kick out of it), and it can also tilt open at the rear. This works great - little extra noise, lots of air flow, miminal if any aerodynamic cost. No deflector needed.

 

I smell a marketing move afoot. As the consumers drive the additons to this car, Toyata will respond. This year there is a touring model, with leather available in both trim lines, after many requeste it. I do believe that Toyata has discovered that many will pay top dollar for the hybrid IF it comes equipped with the features they are used to on their other high end vehicles. If they put everything on the car the first few years, we wouldn't trade up every 3-4 years!! I suspect a sunroof will make an appearance over the next couple of years. With other companies jumping on the hybrid bandwagon, Toyota will do what is necessary to stay ahead of the competition.