Its almost an arbitrary number, but aero becomes measurable in a tunnel around 40 mph in auto set-ups. In your case any improvement in grille area would start to be effective over 80mph. imo..

And remember with hp automotive, "everything effects everything else"

BTW, what is the max speed likely here?

Would I be somewhat correct in thinking you spend 50% of the run gaining the last 20% of speed?

Last edited by jcc; 03/15/19 03:44 PM.
Reality check, that half the population is smarter then 50% of the people and it's a constantly contested fact.