Gadgetory

now run-flat tires are kind of amazing they can be driven under inflated or uninflated at up to freeway speeds 55 miles an hour or so is recommended up to 200 miles in some cases depending on the tire how they do that's interesting here's a conventional tire and if I get on the sidewalls here I can deflect them you I'll be done this with an old tire laying around even on a swing when you were a kid come over here to a run flat though try and deflect that sidewall you'll break your thumb trying to do it extremely strong sidewall structure this way as well as laterally this thing has sidewalls of Steel quite literally and can support the weight of the car without any air inside helping out that's what makes it work Road side when you get a flat with a run flat tire you won't be out there on the side of the road trying to change a wheel which you may have never done before the side of the highway is no place to learn a new mechanical skill blow outs run flats are pretty much immune to sudden pressure loss even without air they pretty much maintain their shape in fact the first indication anything is wrong may come from the tire pressure alert on the dash not the feel of the steering wheels space and wait run-flats allow car makers to use the space formerly taken by the spare for something better like the battery in the case of this BMW and loses the weight of that spare wheel tire and jack now the cons run flat tires tend to cost more and way more to things you don't want an entire first of all the cost easily twenty twenty five percent more than a conventional tire about the same size I'm ballparking there but that's not unusual that's a big price difference secondly the weight you can't feel this but if I pick up this run flat it's really dense this similar tire that is conventional and about the same size is actually dramatically lighter and that will change the dynamics of how your vehicle handles and rides less weight is always better in any part of your wheels brakes tires or suspension arms harder to find you may not find a run flat in your size sitting on the Shelf when you need one so while the run flat may get you to the nearest service station easily you might spend a long time waiting there the scenic car tech team has reservations about being stuck with the limited tire selection when you have run flats Hondas and Acuras that came with michelin packs run flats for example can only use those tires unless you do a complete change that could include wheels tires and tire pressure sensors and a recent JD Power survey found that owners of performance oriented cars with run flats are only half as likely to recommend their tire brand to someone else the weight and feel tend to deaden the cars handling Honda was an early user of run flat tires but they used a different system than this something called the michelin packs technology it was a hard plastic shell that lived inside the tire and supported it same basic idea but they bailed out in 2009 don't put those on cars anymore that leaves BMW mini and some Corvettes as the main users today of the stiff sidewall technology like I've showed you that actually is not enough to make an industry-wide revolution what did replace the run flatter keep it from really gain to fruition we're better technologies for traditional spares which we've covered actually to go look at you