Trackday Diaries: The Idiot's Guide to Left-foot Braking.
There was some mild consternation among the Best&Brightest when I admitted to left-foot braking the Focus SE in traffic. To a man (or woman), our readers were not pleased at the thought that I might be bumbling along a freeway at ten miles per hour or so, alternately pressing the brake and accelerator with one foot per pedal. One wonders what they might have made of LJK Setright’s famous assertion that he occasionally drove cross-footed, pressing the accelerator with his left foot and the brake with his right, “to ensure that driving is a conscious, not unconscious, activity.”
In any event, I would suggest that there is one scenario where you may left-foot brake, one scenario where you should, and one where you absolutely must not, and I’ve detailed them below.
Before we discuss all the different ways in which you can left-foot brake, let’s make sure we understand how the pedals are “normally” operated in a street car. The driver sits down with his left foot braced against the floor — or the dead pedal, where such a thing can be found. The role of the left foot is important here. Consider this: when a car accelerates, the driver is held in place by the upright portion of the seat. When a car corners, the driver is held in place by the seat bolsters, the seatbelt, or, in worst-case scenarios, by the door and the center console. When a car decelerates, however, what holds the driver’s body in place? A reasonably fit individual might be able to resist 1g of braking force by pressing his hands against the steering wheel; that’s kind of like doing a pushup with your hands close together. Some seatbelts will inertia-lock and hold the driver in place, but that’s not a mechanism on which the driver can count.
Ninety-nine times out of a hundred, when a car slows suddenly the driver is retained in his seat by applying pressure with his left foot against the floor or the car or the dead pedal. You could test this yourself by driving across a parking lot with your left leg tucked under your bottom, hitting the brake pedals with your right foot hard enough to engage ABS, and then observing what happens. Make sure there’s nothing around for you to hit, of course, because chances are you’re going to slam against the steering wheel pretty hard and lose some or all of the control you have of the car. You’re certainly going to lose any ability you have to modulate brake pressure during the episode; the weight of your body will be transmitted through the brake pedal and you won’t be able to stop braking until you’ve come to a halt.
The above scenario is why your high-school driving instructor wouldn’t let you left-foot brake. It’s not a reasonable way to operate a vehicle on the street at any kind of speed. If you’re in a car as a passenger and you see the driver using the left foot to slow said car, you should speak up. It’s dangerous and not advised, period.
What about when you’re crawling in traffic, however? In situations like that, I left-foot-brake all the time. I wouldn’t say there’s anything wrong with it. At five miles per hour, it’s pretty tough to get yourself killed with even a full-pressure random brake application. I also have no reason to believe it’s particularly hard on brake linings or torque converters. The forces involved are a fraction of what the car can generate. I just swapped out the front brake pads on my Town Car for the first time — at 93,500 miles. I haven’t changed the rear pads, because they don’t need it yet. If driving said Town Car in traffic with both feet is hard on the brakes, I have to wonder how long they last if you don’t drive the car with both feet. 200k? Forever?
Professional drivers — as in professional livery drivers, not LMP2 pilots — use both feet in traffic to smooth the passenger experience. If the brake is applied as the accelerator is released, and vice versa, it’s possible to creep through traffic without jouncing the VIPs. As some of the readers noted, however, most modern cars are considerably more sophisticated than Panthers. They’re engineered for legal considerations as well as mechanical ones, and one of those considerations is that the brake must always stop the car immediately even if the accelerator is being pressed. Therefore, to avoid being the subject of a “60 Minutes”-style hatchet job, nearly every car you can buy today closes the throttle the minute it thinks you’re operating the brake. As I noted in my Focus test, double-clutch automated manuals are also confused by operating both pedals at the same time, even briefly, and they’ll misbehave as a result.
So, let’s review. Driving down the freeway? Put your left foot on the floor and leave it out of the proceedings. Stuck in traffic? If you have a torque-converter car without the latest in paranoid electronics, feel free to use both feet. If you have a DCT or, say, a modern Audi sedan, your experience might vary.
That covers all possible experiences on the street. What about on the racetrack? Here we have a different set of rules. On a racetrack, we have a five-point harness holding us in the car. We don’t need the left foot to support the body during hard braking. If we don’t have a five-point harness, a CG-Lock also works very well. It holds the lap belt in a fixed position and retains the driver’s body in the seat during deceleration. Every Stock-class autocrosser worth his salt uses one. I brought one to the CTS-V Challenge only to find that Bob Lutz’s car, which he shared with me, already had a heavier-duty variant of the CG-Lock installed.
Once properly belted and restrained, we are free to use the left foot to brake. In stick-shift cars, we can only do so when we aren’t downshifting for the turn, and that doesn’t happen very often. In an automatic-transmission car or an automated manual, however, we can left-foot brake for each and every turn, as I did in my recent on-track test of the Camry SE.
Noted IndyCar driver Alex Lloyd wrote a column about why you should brake with your left foot at all times. He points out that you can lose up to one second every time you move your foot from the accelerator to the brake and vice versa. That’s totally legit, and it’s the biggest reason to LFB on a racetrack. (The second-biggest reason is the additional ability you get to adjust your car in the midcorner if you’re free to use both pedals in sharp succession.) It’s safe to say that there are very few professional drivers (in the non-livery sense) using their right feet to brake unless they’re concurrently using their left foot to operate the clutch.
His claims that you should use the left foot to brake on the street so you can go faster on said street, however, should probably be disregarded. If you’re braking hard enough to really make time on a fast back road, you need your left foot to brace your body. I forgive Mr. Lloyd for forgetting to mention this, since my guess is that he’s been too busy racing IndyCars and doing exciting stuff like that to put in a couple of thousand laps in the right seat of student-driven cars at open-lapping events. Unfortunately for me, I have not been too busy to do exactly that, so I’ve seen the negative outcomes that happen when people try to use their left feet to brake the car while wearing a traditional three-point belt. I do agree that you can theoretically brush your left foot on the brake in fast street corners to adjust the car, but what happens if you’re in the middle of doing that and a deer runs in front of you? You’re going to max-pressure the brake pedal with that same left foot, and then, as Al Pacino tells DeNiro in Heat, “brother, you are going down.”
It’s best to think of left-foot braking as the equivalent of biting your girlfriend. You can do it softly when you’re just messing around, and you can go for it when you’re full-throttle, but in everyday situations it might be unwelcome. No, wait, that’s a terrible analogy. Let’s just say this: that when it comes to left-foot braking, as with everything else, the answers aren’t as straightforward as they might initially seem.
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