My son is 13. Is he too young to use a running chute?

no, but I tried one, I dont think it gives enough resistance.

It does if it's a windy day! I like sleds better though. You can add as much weight as you want and are pretty cheap if you want to make your own.

I would not let him use one...

Chutes tend to make athletes run differently than they normally do. With that resistance pulling him back you may see his arms swing out or unbalanced strides. I would focus on form running on plyometric jumps to increase speed/strength. Gaining proper running technique is essential to developing speed at that age.

If you want a resistance parachute, go to jumpusa.com they have the best one by far! It's huge

I agree with JCSpeed about the value of resisted running. Either chutes or sleds, if they create too much resistance, will alter the mechanics of the runner. Its probably not a bad idea as a supplement, but I would be very cautious with how often I did it.