When Infiniti’s new M sports sedan hits the market next year, it will be available with an optional tech package that includes a mighty strange feature for a sports sedan. A so-called Eco-pedal will actually resist you overactive right foot, providing feedback that Nissan says is intended to discourage inefficient (read: enjoyable) driving styles. The payoff is supposedly a five to ten percent improvement in efficiency, although convincingly proving causality for those results can’t be easy. After all, if you’re driving for efficiency, you don’t need the gas pedal to be telling you to go easy. Luckily, even if you do pay more for the package that includes this feature, it will be switch-offable. Or ignorable. “The driver can easily disregard the resistance,” Infiniti product planning director John Weiner tells Automotive News [sub], “or turn it off altogether. But if you heed the signal and do as prompted, it can improve fuel economy.” Whatever happened to those “upshift now” lights that were so popular on the dashboards of cars in the 80s?