Making The Right Neu Motor Choice?

[Pedebeater]

I am saving up for a monster max combo. I was wondering if it is really worth it to use 6s on the 1515 1y instead of using 4s on the 1512 1y. What kind of preformence difference will there be? I will monst likely be running this combo in a 1/8 truggy, probably a Ofna Jammin.

http://www.castlecreations.com/produ...5/1515-1y.html

http://www.castlecreations.com/produ...2/1512-1y.html

Thank you for all of your help.