The ‘heavy mod’

This interesting tale appeared overnight, prompted, perhaps, by my grousing about certain large vehicles that have been left blocking the driveway recently. While I have no time to investigate, and the source is somewhere in the anonymized ether, the claim is that there is a clandestine industry hereabouts that trades in something called ‘the heavy mod.’

The story goes like this: wealthy locals have long favored a particularly large 9-passenger GM vehicle, marketed variously as the Chevy Suburban, GMC Yukon or Cadillac Escalade for transporting their (typically) 2 children around to school, soccer, dance lessons et al. The rational for such giant gas-inhalers (one model of the Suburban is rated at 10 mpg city/14 mpg highway by the EPA) is protection – the very large vehicle is supposed to protect the precious occupants in the event of a crash.

A well-publicized NTSB traffic-accident study disputed that notion, however, noting that these giant machines were basically trucks with high centers of gravity that made them more prone to rollover, which is among the worst kinds of accident producing more serious injuries than crashes not involving flipping over.

Banking that the giant-car set would be loathe to give up their shiny, black, presidential-looking behemoths, but didn’t wish to ignore family safety, an entrepreneurial shop began bolting lead plates to the underbody of these GM models as a way of lowering the car’s center of gravity.

The lead plates – typically four 500-pound slabs located strategically under the chassis – nearly match the car’s 2900 pound rated load capacity and cause it to ride oddly low, so the shops modify the cars’ suspensions with heavier springs, shocks and other components, including heavier-duty wheels and tires.

Of course, with almost 50% more weight, the car is no longer a sprightly performer, taxing even the 500-horsepower engine available as a factory option. The solution is to fit a supercharger to the car’s mammoth , 6-litre power plant, approximately doubling the horsepower, and voila, the ultimate family cruiser.

The whole package reportedly tops out at 8,000 pounds – 4 tons – up from a stock curb weight of 5,000 lbs. The cost of the mod starts at a measly $50,000 (and can range up to $90,000 or more), which is more than the cost of the car. And yes, 60% heavier means 60% lower gas mileage (premium fuel, of course) putting the car’s city mileage somewhere south of 5 MPG.

But, don’t rush to the yellow pages or Google to find your nearest heavy mod shop. San Mateo County’s Toxic Materials Abatement Act places very strict limits on industries that store and process toxics, and lead is high on the list of prohibited, or at least, highly-regulated materials. The mod shops in question are small garages, mostly located in the Highway 101 corridor  east of the Caltrain tracks, and don’t have the resources to comply with the materials regulations, so they operate sub rosa.

The car itself, with a ton of lead in it, is a rolling superfund site from the perspective of the County health department, which takes a very dim view of large quantities of lead being stored in residential areas, e.g. your neighbor’s driveway. The cars are thus made to look and ride almost exactly like their stock counterparts, to escape suspicion.The only giveaway, apparently, is the load rating code visible on the side of the tires. Can this be true? Anybody ever see one of these things? Better check Urban Myths for this one… [Update: before you believe this screed, go here]