As I pointed out, the top 20% account for 60% of spending. $4 gas doesn't mean shit to them.
$5 might cut is down below 2% GDP, and it ain't going to $5. $4 is not a shock even long term.
We are much more efficient.
The lower bound of the top 20% isn't really all that high. We're talking household income in the $90,000 and up range. The top 5% might not think twice about $4 gas, but that's not true for the rest of the top 20.