May be an easy question?

[Concrete]

Bob,

understood
that is why I said "about" 2 times
- I did not want to explain non uniform disk inertia

HypermilingNoob said "everyone talks about light weight rims"
I've heard that talk too - and low weight rims becomes an imperative
and most of the "talk" is bogus

I just wanted to inject some data

ditto on the pressure - best first mod
my truck did not really coast before I got the pressure right
and if your are coasting - inertia becomes your rechargeable friend