we run fixed 3.7 gearing and no tire sauce.
I have run cyclone, tamyia 415, shafty yokomo, tc3, xray t2, tc4.
They all run very very similar times for me.
I often swap cars with a "slower" guy in practice so he can get the confidence that his car IS fast
I run xray as my asphalt track needs a very carpet like setup and xray has more carpet type options than any other manu, different stiffness arms chassis top deck etc...