A Michelin engineer who tests driver behavior once told me, “Most people, when faced with cornering beyond 0.4 g or hitting a tree, choose the tree.”
Well, I guess a tire guy would know, right?
Judging by typical cornering speeds on public roads, and my mother-in-law’s reaction to me pressing way beyond 0.4 g, I’d say he’s probably right. Usually, the g-force, or gravitational force by definition, gravity is 1.0 g is felt in the downward direction as one’s weight; it’s what keeps your feet in contact with the ground. A lateral g-force such as what one experiences in a car that is cornering is also measured in the same units (g). Most cars today can corner at more than 0.8 g; 0.4 g translates to about 45 mph on a freeway entrance ramp marked at 35 mph.
Not having an accelerometer handy geez, another argument for an iPhone I can’t verify this personally, but somehow that seems awfully modest. Or maybe I’m driving harder than I think I am. The ramp from I-44 eastbound to I-35 southbound, which I use five days a week, sometimes six, is about a 75-degree curve that I routinely take at 60 mph unless it’s wet or the 6:30ish traffic doesn’t permit. (I’m going from a road where the speed limit is 60 to a road where the speed limit is, um, 60, so 60 seems like the most logical speed.) In fact, I consider this a test of car and/or tires: if there’s any squeal, it’s a fail. Hardly anyone else pulls this sort of stunt, which makes me wonder if I’m pushing too hard.