palmerg

Looking to get windows tinted if necessary on the S7.
Anyone know the VLT% (Visable Light Transmission) on the factory windows?
No info on the Audi USA website.
North Carolina Law limits VLT to 35% that is NET so its the Film + the existing window.
I have a note into my dealer but not expecting much detail unless they happen to have a meter around
Thanks in advance,
Gary

tenspeed

Some of the northern states require 70% or more Visible Light Transmission. A tint shop or any law enforcement officer should have a meter. Go ask at the doughnut shop...

slickrick68

I am curious as well if anyone know...

palmerg

I don't have the car yet so LE or tint shop or "donut" shop prolly won't work
Just tryin to get a sense for what VLT would be on the film added to the VLT of the window on the car. I've seen a few vids showing the meter, they say, the cops use. From what I have seen the readings are +/- 5%. Just want to avoid confrontation. I figure that the factory windows aren't very tinted.
Thanks for the reply!

tenspeed

Paragraph 6 from the NY Times article:

"Car manufacturers live by the rules of the National Highway Traffic Safety Administration. All car windows from the manufacturer must allow 70 percent of visible light through. What people think of as untinted car windows are actually a 70 percent tint. The federal rules for trucks, which includes S.U.V.'s, are less stringent. They are required to have a clear windshield and front windows."

MOTORING - Seeing the Light. Then Again, Maybe Not. - NYTimes.com

palmerg

Thanks! Great reference!
So, if NC requires greater than or equal to a NET VLT of 35% (.35) on sides and rear that means:
If factory windows are at 70% (.7) VLT - we solve for X
.35=.7(X)
.35/.7=X
.5 = X

Checking: .7x.5=.35 or 35%

So if factory windows are at 70% VLT I can use a film rated at 45% (to be safe) VLT and be a law abiding citizen of the great state of North Carolina

BTW: The article states that factory windows are 70% tinted. That is not true if they are 70% VLT they are really 30% tinted

tenspeed

I don't know if you should be multiplying and dividing or adding and subtracting when it comes to tint. You could take whatever you're driving now to a tint shop, put a sample on you present car and check it with their meter. Gives you a chance to see their work, products and customer service.

Good catch!

palmerg

I'm almost positive it's a multiplier when it comes to cumulative percentages. Trouble is I'm in Italy and I drive a european car - probably don't care much about the NHTSA here. I'm sure I can handle it on our return stateside - just wanted to try and be ahead of the game. Its not only film VLT but also other factors I will have to research.
Bottom line is you probably answered my question about factory tint an that was helpful.

VLT of Glass times VLT of Film = NET VLT

from Johnson Window Films, Dealer Resource Center

slickrick68

I went and had my 2012 a7 measured...drivers window was 81%, pretty light compared to other OEM glass such as some Infiniti's.

palmerg

I was wrong, dealer in Charlotte was very helpful. I settled on 3M crystalline 90 clear film for the windshield. It's applied to the inside and blocks close to 90% of sun energy including UV heat generation. Also getting 3M Color Stable tint film (NC limits) for all other windows including rear hatch. Setting me back about $750 + tax. Maybe a little steep but it will be done when I pick up the car and that is worth a little. Probably won't get the full wrap. It's a little to expensive and I love to wash & Wax my own weekly anyway. Also clay at least once a year, we'll see...
The tint film will be a welcome addition, I'm convinced.