Stop being a fool!
You can never answer a question properly. You simply respond with expletives and your own inane questions.
You are quoting one guy who has carried out some research, the details of which you have never provided. You 'presume' the track was pristine, you 'presume' they waited a week between surfaces, which in itself makes it pretty unreliable. We don't know if the athlete/s being tested were training between each run? We don't know what the difference was in wind or weather conditions. We also don't know if he carried out these tests over a variety of distances. How many athletes were in the pool being tested?
Even if his research is of value, that 1.5% works out more like 0.7 a lap than 1.0. In truth no one can say for certain what the difference was. Many experts and old athletes, including Clarke at the end of his career, stated that the difference is much nearer to 0.5 per lap.
Snell has stated that a well kept grass track was better than a well kept cinder one. So there is conflicting evidence on all sides. You are not qualified to be the final arbiter on such an issue.
While we're at it, if you're now saying that lack of drafting is only worth 0.7 per lap and the same for cinders to synthetic, then that must surely throw Ryun's alleged (lol) 3:41 Mile ability into question for you!?
3:51.1 ht was more like 3:51.3 FAT.
0.7 x 4 for dirt = 2.8
0.7 per 400m for 1000m (no one gets drafting from the gun, and usually only from 200m) = 1.8
So that comes to 4.6 secs
3:51.3 - 4.6 = 3:46.7
That's practically 3:30 flat for 1500m, and miles away from your deluded 3:24/3:41.
Now you're going to have a fit, call me all the names under the sun and reduce these down a further 5 secs because it was hot, or he had a headache or farted at the wrong moment!
There is no definitive evidence as to how much slower a dirt track was compared to a first generation synthetic one. And once again, you hijack a perfectly interesting thread and pollute it with your own agenda by belittling others. About time you grew up.