Automotive Inanities–Tires

The other day, I was visiting my friend’s repair shop. He was working on a late 1980s Subaru wagon. I noticed it had 13-inch wheels and four-lug hubs.
You never see this anymore.

That’s too bad.

The smallest wheel/tire you’ll find a new car riding on is a 15-incher. My ’76 Trans-Am, a big (and heavy) muscle car also has 15×7 wheels. But it is a muscle car. Large (for its time) wheels and fat tires made sense because it has a big V8 and lots of power and you need as much traction as possible to keep it all tied down. The fact that bigger wheels and tires add weight and increase rolling resistance and so hurt gas mileage isn’t something people who buy muscle cars tend to worry much about.

But why put sixteen and seventeen inch wheels on ordinary family sedans? On economy cars? It makes as much sense as inviting the Pope to the Bunny Ranch.

And yet, new economy cars do come with at least 15-inch wheels and usually sixteens — with seventeens sometimes optional.

This is one of the reasons why the fuel efficiency of modern economy cars is pretty mediocre.

It would be interesting to take, say, a new Corolla or Civic and replace its factory fifteen or sixteen inch wheels with sane-size — for an economy car — fourteen or thirteen inch wheels and skinny, low rolling resistance tires and see what effect this has on gas mileage.

It would probably improve it by 5 MPG. Maybe more.

The car’s high-speed cornering capability would be reduced. But how many American economy car drivers partake of high-speed cornering? How many American drivers do?

I don’t see it much, myself.

And there would be no effect on safety. Wheel/tire size doesn’t alter a vehicle’s crashworthiness, its ability to withstand impact forces in a crash. So it’s something the car companies could do tomorrow without NHTSA ululating outrage . . . if buyers expressed interest.

They probably would not. Why? Because we live in Cod Piece America — our cars serving as expressions of virility we no longer possess. We sit, emasculated, in traffic. “Buckled up” and compliant, ready to present our papers at the next probable cause-free checkpoint. But while we are meek and submissive, our cars look tough.

Yes, it’s true emergency braking distances might increase a little due to the reduced contact patch — but the much superior braking systems (almost always four wheel disc and always with ABS) that all modern cars have makes up for that, especially vs. the older stuff that lacked those features.

Here’s another thing that’s gone for reasons that don’t make much sense: Three across seats in front and rear.

I came across an old ad for an Aries K-Car coupe. A two-door that was advertised as seating six people.

And, did.

Three up front and three in back. Notwithstanding it was about the same physical size as a new Corolla sedan — which realistically seats four (though advertised as being able to seat five).

How?

The car had three-across bench seats. No stupid “sporty” center console in between a pair of equally stupid (if the car is being used to transport people, as opposed to giving its owner “sporty” pretensions) “sport” bucket seats.

Once upon-a-saner-time, sport buckets (and center consoles in between) were to be found in . . . sports cars. And muscle cars. Just as you expected to find four-wheel-drive in a truck (but not a Corvette). Today, the interiors of trucks are Corvette-like, with “sporty” bucket seats and “sporty” center consoles with console-mounted floor shifters that waste space for the sake of image.

Another feature the K-car had (and touted) that’s been forgotten is the flat floor.

Which was a side benefit to the front-wheel-drive layout, which was a new thing in the early ‘80s — a time when most cars (even economy cars) were still built on a rear-drive layout. That meant engine and transmission up front (and mounted longitudinally, or front to rear) with the drive axle in the rear, the two connected by a driveshaft. Which ran from front to rear within a “tunnel” pressed upward into the car’s floorpan, which neatly divided the car’s interior space in half.

But in a FWD car, the engine is mounted transversely, or sideways (more compact) and it drives the front wheels, through a combined transmission/axle assembly (much more compact) called a transaxle. This eliminates the need to press a “tunnel” for a driveshaft into the floorpan, which is now flat. This allows the person sitting in the middle (on a three across bench seat) to sit normally — without his knees up against his chest, in the fetal position.

So how come today’s FWD cars (which is almost all new cars) have regained the hump in the floorpan?

It’s for two reasons.

One, new cars sit lower than they used to and that creates clearance issues for things such as exhaust pipes and other plumbing. For two, all-wheel-drive (another victory of marketing over common sense) is becoming extremely common and it requires a drive axle to the rear wheels. Re-enter the “tunnel” to accommodate it — and bye-bye three-across seating.

And they ask me why I drink . . .

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3 Responses to “Automotive Inanities–Tires”

  1. Clair Oppriecht says:

    And, the larger wheel diameter and width is designed into the suspension geometry and for many cars you can’t get a narrower rim for your Winter tires. The skinnier the better for snow and ice. “Fat” winter tires are better than “Fat” All-Seasons, but you lose a lot of winter performance you could be enjoying. I wish you’d mention Winter tires occasionally, and here’s a good chance to have done it; you are not helping educate people about their benefits. It’s like there is a conspiracy of silence about this topic. Is everyone being paid-off by the cops, tow-truck drivers, body shops, ambulance drivers and hospitals etc.? Are Winter tires only for some secret society like “Free Road Masons” or something? I don’t get it; I wish someone could give me a “GOOD” reason for the silence. I will admit that The Tire Rack and others who sell and promote Winter tires are well represented in ENTHUSIAST PUBLICATIONS (only read by Road Masons); but even in them, many readers assume “They’re trying to sell me something” and don’t “get it”. Even preaching to the choir falls on some deaf ears; but why the silence everywhere else in media and every other entity that claims to have our best interest at heart? I can’t believe you personally use them; for everyone I know who does is “over-the-moon” about them and tells everyone they care about about them. What’s up?

  2. Chris Rees says:

    Perceptive independent thinking – and I agree 100%!

  3. toly arutunoff says:

    tall wheels and skinny tires result in $$$ after hitting a pothole. I bought wheel/tire insurance for our 2014 Audi rs7 and after 2 potholes–one on a velvet-smooth section of eastbound I-40 in Arizona–I would’ve been out almost $2k if it hadn’t been for the approx. $600 insurance cost. 15″ wheels with, say, 8.20×15 tires (old bias-ply spec) would’ve shrugged the potholes off.