60 mph is about 12 revolutions per second. My friendly tire shop spun one of my wheels to that speed WITH and WITHOUT the trim rings. In several tries, there was no more than a 1-2 second variation in the time it took to slow down to a stop. Sometimes it was one way, sometimes the other. My guess - there won't be any measurable difference in fuel economy if the trim rings come off the car, and it sure looks better!
Your conclusion may, very well, be correct. But the test that you used to arrive at it probably is not. It takes into account only wind resistance of the spinning wheel, not that of the forward movement of the vehicle which may disrupt smooth flow over the spinning wheel more without the trim. Still, if you like the appearance better and don't mind a miniscule loss of mileage then, by all means, take them off.
Dang Evan, I was all ready to fall for that one, but then you came along and brought up the flaw in the theory. Your opinion on the issue makes perfect sense and once again shows you to be a very bright guy. My empirical conclusion is that it seems to make no difference in my mileage. My current average, without rings, is 56.5 with 250 miles on the tank.(nine bars BTW) The big hits to my mileage are the short errands during the day and cooling off the car in 93 degree weather.
