Tint and GPS Discussion (broken out from Obscure Facts thread)

Re: Most Obscure Gen III Facts (way out there)

That's just nuts! Why the heck would any manufacturer put the GPS antenna INSIDE the car, especially buried inside the instrument panel? I have an older portable Garmin ... reception is fine when walking about, but inside any car gives it problems. The glass attenuates a good portion of the GPS signal, and the metal roof blocks the signal entirely. A GPS signal is already one of the weakest transmissions on the planet, why make it any harder and less reliable to receive? Combine the antenna with an external radio antenna, or a flush-mounted patch on the roof. I'm disappointed if Toyota really did this!

 

Re: Most Obscure Gen III Facts (way out there)

It is not burried. It is just under the surface, where the instrument panel meets the lower edge of the windshield. Newer Garmins work fine inside a car, so this location should not be a problem.

 

Re: Most Obscure Gen III Facts (way out there)

Well, we've not heard from any posters who've had problems with the NAV in their tinted Prius, have we?

 

Re: Most Obscure Gen III Facts (way out there)

Some of the newer tints do not use metallic dyes in the film, but ceramic particles. This reduces the effect of signal loss when the windows are tinted. There is also a windshield film that eliminates most of the UV light entering through the windshield which eventually causes your dash to crack and split. This film does not adversely tint your glass, but does make it look a bit bluer...

 

Re: Most Obscure Gen III Facts (way out there)

1. My dealer didn't tell me this and I had the windows tinted anyhow. This was arranged through the dealer when I bought the car so they were fully aware I was doing it.
2. My GPS works fine, even when in the middle of nowhere at 9k ft. I was also able to use it to locate Mexican restaurants in San Jose with the POI feature.

I should note that in CA we can't get the front windows tinted if that makes any difference. I just have the back three done.

 

Re: Most Obscure Gen III Facts (way out there)

You can get the front side tinted, but only to 70% legally. You can probably get away with 50% and even 35%. Go 20% or lower and you're at great risk of getting pulled over.

 

Re: Most Obscure Gen III Facts (way out there)

Here is the VC section for CA, 26708 et seq, which addresses window tint on the front roll-downs. So, if you have a note from your doctor-OK. Or apparently if you have window tint which apparently permits 70 to 80% light transmission and you have all the documentation from the manufacturer and installer with you, filled out in your name.

I included section (C) for those of us who like a tint strip across the top of the windshield to block sun, which works quite nicely.

(10) Sun screening devices meeting the requirements of Section 26708.2 installed on the side windows on either side of the vehicle's front seat, if the driver or a passenger in the front seat has in his or her possession a letter or other document signed by a licensed physician and surgeon certifying that the person must be shaded from the sun due to a medical condition, or has in his or her possession a letter or other document signed by a licensed optometrist certifying that the person must be shaded from the sun due to a visual condition. The devices authorized by this paragraph shall not be used during darkness.

(c) Notwithstanding subdivision (a), transparent material may be installed, affixed, or applied to the topmost portion of the windshield if the following conditions apply:

(1) The bottom edge of the material is at least 29 inches above the
undepressed driver's seat when measured from a point 5 inches in front of the bottom of the backrest with the driver's seat in its rearmost and lowermost position with the vehicle on a level surface.

(2) The material is not red or amber in color.

(3) There is no opaque lettering on the material and any other lettering does not affect primary colors or distort vision through the windshield.

(4) The material does not reflect sunlight or headlight glare into the
eyes of occupants of oncoming or following vehicles to any greater extent than the windshield without the material.

(d) Notwithstanding subdivision (a), clear, colorless, and transparent
material may be installed, affixed, or applied to the front side windows, located to the immediate left and right of the front seat if the following conditions are met:

(1) The material has a minimum visible light transmittance of 88 percent.

(2) The window glazing with the material applied meets all requirements of Federal Motor Vehicle Safety Standard No. 205 (49 C.F.R. 571.205), including the specified minimum light transmittance of 70 percent and the abrasion resistance of AS-14 glazing, as specified in that federal standard.

(3) The material is designed and manufactured to enhance the ability
of the existing window glass to block the sun's harmful ultraviolet A rays.

(4) The driver has in his or her possession, or within the vehicle,
a certificate signed by the installing company certifying that the
windows with the material installed meet the requirements of this
subdivision and identifies the installing company and the material's
manufacturer by full name and street address, or, if the material was
installed by the vehicle owner, a certificate signed by the material's
manufacturer certifying that the windows with the material installed
according to manufacturer's instructions meets the requirements of this subdivision and identifies the material's manufacturer by full name
and street address.

(5) If the material described in this subdivision tears or bubbles,
or is otherwise worn to prohibit clear vision, it shall be removed
or replaced.

Amended Sec. 77, Ch. 1154, Stats. 1996. Effective September 30, 1996.
Amended Sec. 1, Ch. 476, Stats. 1998. Effective January 1, 1999.

 

all windshields have UV protection since the 70's/80's. the glass manufacturers have been putting UV protection in the plastic film that is inside the laminated windshields for the past 25 yrs or so. it's the side and rear windows that typically don't have the UV protection. in the past, only high end cars had UV protection all the way around. think back to the early 90's when Infinity came to be, the standard Q had UV protection all around except where the "mobile phone" antenna needed to be placed. that area looked like a big square on the back window. back in the day, we needed exterior antenna's and big black bags to carry our mobile phones.

i don't know how much of the OEM glass in our Gen III cars has UV protection, but based on history, i would think our windshield definitely has UV protection.

 

Re: Most Obscure Gen III Facts (way out there)

My dealer is installing Llumar tint, and I specified it be ceramic to avoid this issue. The SET installed port tint is also ceramic. My Prius III came off the truck yesterday and should be ready Monday or Tuesday for pickup, so I will update the tint specifics then.

 

I have Nav and dealer-installed tint. No problems.

 

I life in MS, and we are allowed 28% tinting except the Windshield, I had my local auto glass tint my side and rear windows to 30%, GPS is just fine.

Florida Window Tint Law - TintCenter.com

Florida allow much more tinting in the back of the car, if the GPS is under the windshield, it may not make much difference the back is tinted.

 

sorry dont see the issue. i have 2 portable GPS units with built in antennas that work just fine inside the car. if there is any loss, i would not know it, since neither was hardly ever used outside the car. including my cellphone which, granted works with both triangulation and GPS to determine locations.

 

Metal coatings and athermic windscreens used to affect early GPS receiver chipsets but this has long since ceased to be an issue. The current crop of GPs receivers can operate more quite happily behind windscreens with metal coatings and even screens with quickclear heated elements.

This is a non-issue as far as I can see. Any tint that had sufficient metal in it to affect a GPS receiver (of the modern SirFStarIII, GlobalLocate etc) variety would be illegal I suspect and possibly not even transparent!

 

Unless I'm wrong, all glass is UV blocking. You can't get a sun tan through a window for example.
The GPS antenna is under the windshield, so unless you tint the windshield your not affecting reception.
There used to be Ford vehicles with "instaclear" windshields with a thin electrically heated metal in the windshield, now that would be a problem. Many aircraft are the same way, and in those aircraft portable GPS reception is a problem.

 

I wouldn't say "you can't", but it is more difficult.

Glass is simply a material that can absorb radiation to a certain degree depending upon the wavelength and energy of the radiation, the exact material composition of the glass, and the thickness of the glass.

It does absorb UV radiation, but also allows a certain percentage to pass through (depending on the variables above). A single pane of typical residential window glass will transmit 90% of UV above 350nm (UV-A), but will absorb 90% of UV below 350nm.

The second part of the "equation" is what causes a sun tan and what damages the skin cell DNA. Both UV-A (longer wave) and UV-B (shorter wave) radiation result in certain degrees of suntan and DNA damage, but it is generally the UV-B that is most responsible for tanning a couple days after exposure.

So yes, window glass greatly reduces the ability to get a suntan in a given amount of time. If you increase your exposure time, however, you can still get a suntan through a single pane of window glass.

Glass can be impregnated or coated with UV-blocking substances, which is typically the case in automotive glass and sunglasses, as well as certain types of residential windows.

 

i can assure you that you will burn if exposed to sunlight filtered thru glass of nearly any kind. the percentage of rays required to cause damage in most people is only a few percent.

sunglasses to be efffective, have to have filter rates in the upper 90's.

 

Especially a magnifying glass.

 

I think that may be IR

http://www.straightdope.com/columns/read/152/can-you-tan-through-glass