Just bought some new tires. The store tried to sell “Swipping” for add’l $10/tire. Pros vs Cons? Worth it or rip off?
It’s called sipe. And no.
Tester
It’s ‘siping’ (making lots of small cuts in the tread), and it’s a waste of money. Think of it this way, do you think the guy doing the siping at your local dealer or tire shop is better at designing your tires than the dozens of engineers at the tire company? Me neither!
That was my exact thought on this siping business. They should refer to it as a swipe-job though, as in swiping unsuspecting peoples money. Glad I don’t let my wife take care of that stuff…
I suppose that sipe and swipe could be interchanged in a case like this. 
U.S. patent: 7,546,861
Issued: June 16, 2009
Inventors: Gia Van Nguyen, Anne-France Cambron, Jeanne-Marie Gabrielle and Frank Pierre Severens
Assigned: Goodyear Tire & Rubber Company
Last time I checked Goodyear was a tire company, employing engineers. The question is why would you want the dealer to be getting medieval on your tires?
Some years ago, it might have been worthwhile for some drivers, but times and tyres change. Not of value for today's tyres.I don’t get your point, impala61.
That patent is for a siped tire/tire siping tool combination, and Goodyear owns it.
I know it’s only wikipedia, so you have to take it all with a grain of salt, but it’s an interesting article, anyway:
Chase
From what I can tell from the patent, it’s for a siped tire from the factory and the blade used in its manufacture, not some tool to be used by a dealer after the tire was made:
"Abstract: A tire has a tread with a plurality of ground engaging tread elements. In at least one of the tread elements is a sipe having a depth in the radial direction of the tire. The sipe has a crossed configuration comprised of two sipes. At least one of the sipes of the crossed sipe has a radially outer portion having three dimensional elements and a radially innermost portion have a substantially linear configuration. A blade useful for manufacturing the sipe has a crossed blade configuration with a configuration corresponding to the formed sipe. "
Typically the optimal sipes are engineered right into the tire. I think the old days like 60+years ago it helped. However modern tires have significantly more design/experience into them including sipes.
I am guessing the $10/tire charge is likely a 100-400% profit on actual cost.
One tire place wanted to charge me $30 for nitrogen or some gas in my tires. I said forget it and they installed it anyway without a charge. Tires can be very competitive in pricing so its the add-on’s and warranties that generate profit for certain tire shops.
Siping contributes to a winter tire’s ablility to gain traction on ice. I doubt there is a lot of benefit in summer tires, probably reduces the life of the tire, and if it wasn’t there from the factory I wouldn’t bother.
Siping is a slitting of the tread blocks that goes back to bias ply tires to enhance traction on ice. It did work then, and properly done can help today. However, tire manufacturing thechnology has evolved since bias ply tires and winter tires now commonly come with proper siping molded right into the tread blocks.
Siping has zero benefit on other than icy roads, and badly done it can adversely affect traction even on ice. In the modern world there is no reason whatsoever for a shop to sipe tires. Any shop that tries to sell you siping is telling you that they sold you the wrong tires.
Where the real benefit for siping is when the tire is approaching wear out. It can get back some of the wet and snow traction and allow someone to economize. It has to be done with the idea that this is a short term, stop gap measure with a limited life.
Unfortuantely, aftermarket siping has been grossly oversold - just like nitrogen.
I would argue that the only solution to tires approaching wearout is replacement. It’s a commonly held misconception that as long as the tire hasn’t hit the 'wear bars" than it’s good. I disagree. The wear bars are bare minimum specified by law. A tire just above the wear bar is unsafe in anything but dry weather. And even then it can’t absorb impacts as well.
Those four little patches of rubber are all that’s holding the car on the road. It’s worth a few hundred extra bucks now and then to be safe. Trying to stretch well worn tires is IMHO foolhearty.
What’s a tyre?
It’s nitrogen, and it’s actually be used quite a bit now, by a lot of places, including dealers - although you may have to ask for it at some.
It doesn’t suffer from expansion/contraction as much as regular air, so it’s a more stable substance. Compressed air also has a tendency to have more moisture (from the compressor itself, and because moisture filters aren’t that great) and sometimes oil, depending on whether or not that’s an oiler in-line, and where it is in the line.
If you live in freezing temperatures, your tires are subject to extremes every day, from the freezing/thawing/freezing, etc of the moisture in the tires, and it can lead to premature tire failure, and faster corrosion of the rim itself from the inside.
At least, that’s what we’re being told.
Peruse: http://www.gminsidenews.com/forums/f53/what-gm-says-about-nitrogen-tires-2005-already-51446/
I’ve already heard a lot about this, but I just use the good ol’ air from my compressor. To heck with their $5 charge in some cases.
Chase
No, nitrogen expands exactly the same as air, both oxygen and nitrogen act as ‘ideal gases’ at tire conditions.
As for the GM comments, two of the three benefits are at best theoretical. The oxidation of the tire from the inside is not a cause of tire wear - have you ever had to replace a tire because of interior deterioration? And the supposed faster loss of pressure has been tested and found to be minimal. People should check tires much more often than that just because of seasonal temperature changes changing tire pressure.
The only issue that has any merit is moisture, but I’ve seen no statements from tire pressure sensor makers to use nitrogen.
Note that GM “does not oppose” the use of nitrogen. That’s much different that “recommends” the use. If it’s free, fine, no problem. Just not worth paying for.
Here’s a great link discussing nitrogen’s effect on tires:
http://www.barrystiretech.com/nitrogeninflation.html
Isn’t it a tire in UK?