2012 Chevrolet Sonic LTZ: Clutches, Anyone? Freshly Smoked!
April 12, 2012
Our longterm 2012 Chevrolet Sonic LTZ's throttle calibration is going to result in premature clutch wear. You read it here first.
Here's the deal. When you engage the clutch from a standstill in any manual gearbox-equipped car, you -- the driver -- feed in the throttle at a rate you think will both a) avoid a nasty bog/stumble, and b) not excessively slip the clutch. After years of driving manual gearboxes, you -- the driver -- have a keenly-honed sense for this balancing act. You do it instinctively now. You probably don't even know you're doing it, but you are.
The problem arises when the car -- which is not the driver -- attempts to execute this balancing act, too, at the exact same time as you -- the driver -- are doing it.
The resulting bumfight between driver and the Sonic's smarty-pants electronic throttle results in WAY TOO MUCH throttle being applied while you're still letting the clutch in, which in turn prompts the little turbo to start spooling up in earnest and the process just bootstraps itself into frantic, runaway clutch-slipping stupidity. True, I haven't yet smelled that distinctive odor of fried clutch lining when driving the Sonic. Then again, I drive with the windows up.
Apparently the Magistrates of Throttle Manipulation residing in the Sonic's ECU are a conservative bunch and always bang the gavel down on the side of "holycrapdon'teverlettheenginestall" rather than taking the more measured approach of realizing that "hey, this meat bag behind the wheel is taking care of things. I'mma let you finish." At which point it would let you -- the driver -- drive the car.
Jason Kavanagh, Engineering Editor