Earlier this month, Ford CEO Mark Fields articulated -- very gingerly -- what seems to be a rising concern among auto industry leaders.
In an interview, Fields expressed hope for a "fact-based" review next year of the federal fuel economy regulations. Current standards target a national average of 54.5 mpg in the 2025 model year.
"Part of it is looking at the consumer acceptance of the technology," Fields said. "But part of it is looking at what has changed since 2011 when we agreed [on the 54.5 mpg goal]."
Fields wasn't picking a fight with the feds. He emphasized that Ford wants to "be part of the solution," not whine.
But you can see the bind that automakers are edging into.
That grand fuel economy bargain, negotiated in the days of frothy optimism about electric-drive vehicles, has gone sideways.
Back in 2010-11, a lot of observers expected $4-per-gallon gasoline to be the norm, and predictions of $5 gasoline were not uncommon. Now, gas hovers around $2.
Predictable marketplace behavior has followed. Sales of fuel-efficient cars are dropping while sales of light trucks soar.
And, oh, yes, in Paris this month, the world's nations vowed to replace fossil fuels with renewable energy.
These conflicting pressures come just as automakers need to load costly electric-drive technology into their vehicles to hit 54.5 mpg. But that could push automakers into a nasty collision with market reality.
As much as fuel economy has been a political and technological issue, in the marketplace it is strongly affected by two economic factors -- volatile petroleum prices and the stubborn cost of electric-drive technology.
The question now is whether those two factors will prevent consumers from buying the vehicles that the industry needs to sell to get to 54.5 mpg.
As Fields put it, "Clearly, price and affordability is going to play an important part in this. That's why it's important for us to do our part to work as hard as possible to get the costs down.
"But also, at the same time, this technology is expensive."