Yeah I ran skinnies on my old 84 for a while. For a street car, it's not worth the hassle. For anything that you're not trying to get every single hundredth of ET out of, they "might" be worth a hundredth or two. On my 84, it was a 351c with a couple JY turbos, ran 6.20's 1/8. I bought the car that way and sold it that way. At the strip one of the little turd front tires went down because of some glass on the return road so I ran home real quick and grabbed the 10 holes with 225/50/15's and put those on. I saw no difference in MPH indicating that there was very little difference in drag. Saw a little difference in ET, because of the additional weight AND they were smaller diameter than the 26" DS-2's. After that deal, I didn't see any benefit in skinnies unless it was a total drag car looking for ET and/or MPH. The taller the tires are the better the ET (slightly)-assuming they don't weight a ton, which is why you see a lot of class racers running 28"+ front tires. Weight is the biggest ET/MPH difference compared to regular street tires. DOT radials are pretty heavy compared to a set of lightweight 3.5" wide wheels and typical drag racing only narrow front tires. On my Maverick, the old school Weld Pro-Star 15x3.5 with the tires, each tire/wheel assembly weighs about 11 1/2 lbs going off of memory (I am too lazy to go dig out the spec book that I have). I don't think the OE 17x8 cobra RIM is that light on the Mustang, not even counting what the tires weigh.