Accordingly, we’ve taken a considerable eight bites at the handling apple.
Steering angle at 0.5 g (also sampled at the skipad) doesn’t seem to need any explanation, but be careful-it’s more than just an expression of the steering ratio as there are lots of squishy bushings, flexy tire sidewalls, and a bit of understeer involved too.
Steering effort and roll angle at 0.5 g of cornering seem self-apparent, but the car’s steering response time to 0.5 g (produced by a sharp steering input) brings into play the opposing influences of steering ratio and tire grip, against vehicle mass and those squirmy bushings and tire sidewalls.
Steering gain, recorded on the skidpad, is how much additional steering angle is required-above what’s necessary just to creep around it at a few mph-to produce 0.5 g of lateral acceleration.
Similarly measured is understeer (or at least this reader-friendly definition of it): It’s the difference between the steering-wheel angle at maximum lateral acceleration and that creeping-speed steering angle just mentioned (note that both of these are presented as percentages to cancel the confusing effect of different steering ratios).
Compared with the relatively simple nature of those first two categories, handling is string theory.