2013 Tesla Model S: Mild Driveway Scrape
November 21, 2013
Six inches. That's how much ground clearance our 2013 Tesla Model S has according to the spec sheet. In light of recent events, Tesla is quick to point out this isn't terribly low compared to other cars. That's true on the face of it, but there's always more to this singular number than meets the eye.
The first question is "Where's the low point?" On a 4x4 it's usually the bulbous axle differential housing. Sometimes it's a shock absorber bracket. There's far more clearance under the middle of the vehicle. Sedans are different. The low point is usually some hanging part of the exhaust system. The rocker panel below the door isn't usually the limiting factor, but it's not far off. Still, you've got to get down on hands and knees and peer underneath to identify the point of first contact.
Knowing this, I was surprised when our 2013 Tesla Models S grounded out (mildly) when negotiating the above driveway, which didn't appear to be particularly unusual when I approached. Yes, the sidewalk is a bit higher than the parking lot, but I certainly didn't feel the need to come at it diagonally as I might have if I'd been in a lowered machine.
Two things: The Models S rides on a generous 116.9-inch wheelbase and its 6-inch low point is pretty much the entire underside of the car between the wheels. The battery box is a huge gray monolith, so the low point is a vast plane instead of a single point on a single drooping component. Technically, the low point occurs on the inch-wide rub/reinforcing strips built onto the surface, but even these run the entire length of the box in several bands.
If the plane theory holds true (or true enough as makes no difference), we can easily figure the Breakover Angle by assuming the low point applies at the midpoint of the wheelbase. The answer: 6 degrees.
Our Model S has air suspension, but the brief scraping stopped just as I was beginning to consider selecting High 1 via a virtual button that's buried a couple of levels in the touchscreen menus. Had I needed it, I'd have had to pause on Mount Driveway 15 seconds or so while I negotiated the menus, found the button, pressed it and waited while the compressor raised me off the reef another 0.9 inches. If that hadn't been enough, High 2 was waiting with another 0.4 inches of lift, bringing total ground clearance to 7.3 inches. The calculated breakover angles in these settings are roughly 7.0 and 7.4 degrees.
There's a Low mode, too, and it automatically drops the Tesla 0.8 inches at highway speeds to improve aerodynamics. As a result, the true running ground clearance of a Model S at speed is 5.2 inches, about the same as the length of the newest iPhone.
Dan Edmunds, Director of Vehicle Testing @ 11,886 miles