Does 2020 35mpg CAFE standards mean the end of muscle cars?

With 35-mpg average economy mandated for 2020, is it "last-call" for today's overcaffeinated muscle machines?

By Frank Markus
Art By Nigel Buchanan

We are witnessing the end of an era. Even as the new Challenger and Camaro prepare for launch, they'll take flight like the last of the dodos. These large, heavy, big-cube, high-horse musclecars as we know and lust after them are unlikely to be replaced by similar vehicles. That's because the life cycle of their replacements will extend to or beyond 2020, the year by which the Energy Bill of 2007 mandates that the overall fleet average fuel economy for cars and light trucks must tally 35 mpg. Tens of thousands of 15-mpg playthings just won't be part of that plan. Already we've seen GM cancel its replacement for the Northstar V-8 and Ford de-emphasizing V-8s in all its future product discussions. But will the party be over? Let's have a hard look at the legislation and its likely impact on one of our favorite market segments.

The first thing that strikes one upon digging into the legalese of the Energy Bill is that it includes almost no specifics. There's the goal of 35 mpg-for cars and for trucks-in 2020, but exactly how we get from here to there is left to the secretary of energy to determine. The combined fleet average is expected to ratchet up in yearly one-mpg increments from today's 25 starting in 2011. Apportioning that average among the fleets falls to the National Highway Transportation Safety Administration, which must use "1 or more vehicle attributes related to fuel economy" to subdivide the cars and light trucks into different classifications. Then, based on manufacturer forecasts of sales in each class, different fuel-economy targets will be assigned to each class to achieve the overall fleet average. Overachievers will still earn credits that can be traded across classes or carried forward or backward. As of this writing, there's no deadline for these details to be presented, but all the manufacturers we consulted expect the "fuel-economy related attribute" to be vehicle footprint (wheelbase times track width).

Such a system will mean that, depending on the size of a manufacturer's vehicles, the CAFE it'll have to meet may be well above (Suzuki) or below (Rolls Royce) the target economy for a given year. This might inspire designers to jam wheels farther out to the corners of a vehicle to maximize its footprint and thereby lower its target fuel economy, but if such visual jiggerypokery throws the sales volumes off and torpedoes the fleet average, CAFE noncompliance fines might be imposed. What happens if demand shifts and the fleet average target is missed, even though every car hits its own target? Nobody knows for sure.

Another open issue: How will plug-ins, full electric vehicles, and fuel cells be counted? Heavily incentivizing these popular alternative-fuel vehicles could prove a politically expedient way of achieving 35 mpg without forcing too many voters out of their beloved tow-vehicles and musclecars.

To find out just what sorts of "replacements for displacement" might power the next-generation musclecars, we contacted the go-fast gurus at the Detroit Three, BMW, and Mercedes-Benz AMG. All were adamant on one point: Performance cannot be sacrificed as it was in the 1970s and 1980s. Corvette chief engineer Tom Wallace echoes everyone else's sentiments: "What matters is pounds per horsepower. Horsepower is technology and displacement. If you can take mass out, you can take horsepower out. If you can take horsepower out, you can take displacement out and improve fuel economy." Lowering mass improves every sporting aspect of a car, so this is excellent news for Mustangs, Camaros, and Chargers, which can afford to shrink a bit. Further reducing mass from cars like the Corvette, however, will require exotic, expensive materials. And, unfortunately, many other efficiency technologies like gasoline direct injection, cylinder-shutoff, variable intake and valvetrain systems, and active aerodynamic aids add weight.