Piston Slap: Mehta Remembers Another Reason to Hate CAFE

Theodore writes:

So the other day I tested a Pontiac G8 GXP, just because I could. I ease away from a traffic light and as I go for the 1-2 shift, it gets hung up. Wouldn’t go into gear. I realize now that what I was experiencing was GM’s dreaded 1-4 skip-shift, except that of course I was trying to go into second, it wanted fourth, and, well, we just weren’t [synchro]meshing. Short of flooring it everywhere (not that I’d mind, just that you can’t always), what’s the best way to deal with – or outright eliminate – the skip-shift? And do any other cars besides GM’s family of V-8 six-speeds have this “feature?”

Sajeev answers:

Oh my damn! That’s my favorite bullshit modification to tilt CAFE standards for an automaker’s benefit. This scam is the most revolting proof that CAFE is a loophole-ridden system designed to make politicians feel good about their actions . . . and not much else. It might also help V8 GM products avoid the gas-guzzler tax, but I couldn’t possibly know for sure. [Ed: nope.]

Sorry, where was I? Right, the G8 GXP you drove that I could not drive.

Back in the day, the aftermarket made a bypass wiring harness that eliminated GM’s awful 1-4 skip shift. Dealer service departments rarely checked, or cared if they were installed. The same is true today, but the technology changed.

Thanks to OBD-II microprocessors (and the hackers that crack ‘em), today’s 1-4 skip shifters meet their maker with an ECU re-flash. It’s simple, effective and not too expensive. But that’s not all, folks: a quality ECU re-flash usually eliminates torque management in GM’s drive-by-wire throttle, increases horsepower for premium fuel by up to 25hp (more for turbocharged applications) and eliminates top-end speed limiters. It’s an epic win on all fronts.

[Send your technical queries to mehta@ttac.com]