Many Garages Not Built To Handle Today’s Weighty EVs

In the last half year or so, a couple of garage failures have raised the eyebrows of investigators in cities like New York and London. In one of the failures, a five-story parking garage suddenly let go, killing one person on the ground.

Probers Check Potential Causes

During their investigation, probers have looked at several potential causes. After all, five-story parking garages are neither uncommon nor are they too big, too. Yet that was the type of garage that crashed down.

The investigators found some common traits between any failed garages:

• They were five to six stories
• There was a random parking pattern
• The parking structures were, on average, 100 years old
• The parking structures may have served in other capacities earlier

Building experts from London were brought in to study the issues. While they didn’t find any “smoking guns,” they did generate enough information to assemble a compelling case for the building failures.

The experts found that the failed garages were about a century old. They also found that the building codes, if there were any, were much laxer a century ago than today. For instance, buildings using reinforced concrete and rebar (iron bars embedded in the concrete) were few and far between in the late 1800s and early 1900s when many of today’s garage buildings went up.. It isn’t to say that it wasn’t used. What is fairer to say is that it drove up the cost of building, and if there were ways that builders could avoid it, they did.

Parking Picture Upside Down

Right away, investigators painted a picture that was upside down. The problem with ancient buildings is that they were never meant to house modern electric vehicles. Experts have attributed the recent New York garage collapse to a case of upside-down storage. They found that in the five-story garage, there were electric vehicles parked on the upper floors. Those floors were not meant to handle the added weight of electric vehicles. Investigators found 50 vehicles parked on a roof that wasn’t meant to handle EVs. Electrics were among the vehicles parked on the roof and top floors of the garage.

Is the added weight a consideration that some buyers consider when buying electric vehicles? Should buyers be concerned about the added weight in making their purchase decisions? Is added weight a factor you cannot dismiss from the purchase decision? The answers are up to the consumers.  Electrics are generally 10 to 20 percent heavier than their ICE counterparts. Or, putting it another way, some of the largest electrics out there, like GM’s $100,000-plus uses batteries, add up to 3,000 pounds of added weight.

The location of battery packs in electrics gives them a real advantage. They sit at the bottom of the vehicle. Because the batteries ride so low, electric vehicle handling is on par with the best ICE-platform vehicles. And don’t forget that EVs don’t have traditional engine-transmission layouts. They rely on either a central electric motor feeding the wheels or two or four motors driving them. This also adds to the weight differential that makes EVs more controversial.

According to an article in The Drive, the weight differential for the Mustang Mach-E is more than 1,060 pounds compared to the heaviest ICE Mustang models.  Lighter models still come out at nearly 600 pounds heavier. The battery packs account for much of the weight differential.

Weight Is Up For EVs

It is the same across the electric vehicle spectrum. For example, Teslas outweigh similar ICE vehicles by more than 1,000 pounds. Generally, Teslas weigh about 4,000 pounds. Tesla Model X models are the Sumo champs of the EV car world, weighing about 5,500 pounds or more than 1,500 pounds heavier than the heaviest standard car models. As noted, the champion porksters of the EV world are GM’s huge Hummers. Even ICE Hummers were the monster SUVs in the early 2000s when they were on sale and popular. According to various publications, batteries lift the Hummer’s weight by 3,300 pounds.

You might think that batteries are the only items responsible for the incredible bulk of EVs, but they are not the only reasons EVs have huge body masses. Though the tires that wrap around the wheels of an EV look “normal,” they are anything but. Why is this so? It is because EVs take tires that are radically different internally and structurally from those of “standard” cars.

Generally, standard tires have been engineered for cars in the 3,000 to 4,000-pound category. They are made to support four-, six-, and eight-cylinder engines and more standard drivelines. They are also made to support other features, including exhaust manifolds, catalytic converters, and suspension parts. Standard vehicle tires weigh about 10 to 20 percent less than EV tires.

It would be nice to slap four standard tires on an EV like the Ford Mustang Mach-E to save a few dollars, and one supposes one could, but it would be wrong. The reason is the vehicle. As we have noted, EVs are inherently heavier than standard vehicles. Surprisingly EVs have crisp payhandling because of the location of the heavy battery packs. The vehicles are inherently safe from tipping because the battery packs in EVs are below the center of gravity. That, of course, is a safety issue. Tires on EVs must cope with substantial torsional forces. Not only are there the standard stresses applied to tires, but the EV increases those torsional forces by some significant factor that we haven’t measured except to say the tires have to handle the added weight of the vehicle plus the massive torque forces generated by the electric motor or motors.

The added weight means the tires will wear down faster than those used on lighter-weight      ICE vehicles. It is just a function of the mass of the vehicle plus handling. The handling piece comes when the driver tries to turn out of the straight and narrow and go right or left. Again, the added torsional forces of the weight and the turning forces mean that tires must be replaced more often.

Standard Tires And EVs Don’t Mix

If you were to try to use standard vehicle tires on an EV to save money, you would have a dangerous mismatch. Standard tires aren’t engineered for electric vehicles. Tires built for EVs are structurally stiffer and thicker than tires engineered for standard ICE vehicles. And, while I am not a tire development engineer, I suspect that the internal geometries are also different because EV tires have to carry appreciably more weight and handle higher torsional stresses than standard tires. If one tried to slap a set of standard ICE tires on wheels, it might work for a bit, but in the long run, the standard tires wouldn’t stand up to the beating.

One would find that the standard tires quickly began to roll over at the bead edge – where the tire wall meets the tire tread. This means that ultimately the tires would go “out of round,” and the vehicle’s handling would be compromised severely. Standard tires can’t keep up with the pounding. They are incompatible.

EV tires are also engineered for quiet running. You would think that, naturally, EV tires would be quiet, but they are not. The reason is the stiffness necessitated by its use with EVs. This stiffness generates noise, translating into booming, which is translated right into the passenger compartment. EV tires must be engineered for quiet and low rolling resistance. Low rolling resistance means the tires can keep a car rolling over a distance without applying power.

You will also find that EV tires must be bulkier than standard ICE vehicle tires. EV tires are about 10 to 20 percent heavier than standard ICE tires. Generally, standard vehicle tires average between 12 pounds and 130 pounds; some monster truck tires weigh much more. Using an average tire weight of 32 pounds, you will find that EV four EV tires average between 460 and 720 pounds. So, if you add the weight of the battery pack and the weight of the tires, you will see that an EV like the Mustang Mach-E is about 1,630 pounds heavier than the heaviest ICE versions of the current Mustang. It is a considerable difference.

City Infrastructure Not Made For EVs

Looking at the infrastructure of the average city, you will find that many of the buildings that host garages are on the older side. As noted in the New York City collapse, the garage building was over 100 years old. It was built when standards were, at best, lax. Given how cities tend to grandfather older buildings, this may be a ticking timebomb waiting to crash.

The best solution for older garages until they can be torn down and rebuilt for the EV generation is that EVs must be kept on the lowest floors, and ICE vehicles can be parked safely on the roof. This way, we can prevent tragedies, and folks who own EVs can be confident they will be safe to be driven out of where they were parked.

Marc Stern has been an automotive writer since 1971. He says "My work has appeared in venues including Popular Mechanics, Mechanix Illustrated, AutoWeek, SuperStock, Trailer Life, Old Cars Weekly, Special Interest Autos and others. You can follow me on: Twitter or Facebook."