[mcrews]

actually, if you would read mods and posts by others, you would see that 'multilpe tanks of gas' have never been used.
1. you can't test in the real world using multiple tanks of gas. (something that seems obvious to the untrained mind.)
UNLESS your sitting in a controlled chamber for the multiple tanks.
2. everyone here uses a-b-a testing. there are plenty of posts converning how to do it but simply stated:
a defined distance-8-12 miles, that you run both ways to offset wind. a= n0 mod, b=mod. I usually run at midday. I always drive the car 15 minutes before the run. I set the cruise control for the entire run. I reset the scangauge at the same mile marker.
i ussully set the cruise at 55, 60 and/or 65. depending on how much time I want to spend
3. by have a controlled test run, I can chart results over months and yrs. I can see the effect of hot summer against cold winter.
4. bottom line, any mod I have every done never took more than 2 gallons to validate.
5. someone might say " you scangauge isnt accurate" "only filling the tank is". that statement misses the point of testing. It doesn't matter if the gauge is 'accurate'. it could be off 10,50, 100%. But it is going to ALWAYS BE OFF THE SAME AMOUNT!
I don't 'reset the internals'. I just set the trip back to 0.
But the fact is that due to the proper setup in the beginning, my scangauge is close enough to the actual consumption.

as for the cost of 'several tanks of gas', that would be $100- 200. i get 400 miles to a gallon. two tanks is 10 hours. How can you control ten hous of driving? and how do you control the test with and with uot? I bill my business time at $225 an hour. If i can get the material, install it and test it in 2 hours, then I'm done. The time spent reseaching and look for multiple sources may be fun but it is not financially effecent.
all of course is just one man's perspective....

ps. mike said "I think, looking at it, it probably only lets through 10% ? (Im guessing, but Id say 10% would be an "at best") "

and you are saying I'm at...........29%????

that is one problem with this tread. No pictures of the items being discussed. and when finally, a picture is introduced by a third party, the expert, Mike, says wow 10%. Yet this entire thread revolved around the larger 30% and suggesting that a better result was improbable.
Finally, the whole 'ramdom' discussion about the angle of the screen....to what point???? Are you going to redesign the entire front end to achieve the 'correct angle' for the screen to work???? that's know as 'waging the dog'.
Go buy a $5 piece of screen and aba.
just had an wild, off the wall, crazy thought........
go buy 3 pieces, test w/ one, the put 2 together, test, then put 3 together ...test.
and dont spend 5 hours looking for a scientific study of randomly laying 3 sheets together and all the holes lining up to create no improvement.