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How does "SIPING" increase fuel mileage? - as some claim

Would siping not decrease fuel mileage?

Discount Tire, I believe, has siping machines.

It wouldn’t increase it, don’t know if it would decrease it. I’ve never been asked about siping at Discount Tire (where I buy all my tires). They do advertise it on their web site. Not something I would do, I trust the tire designers more that the folks at the shop.


Two things. First, aftermarket re engineering a tire is pretty much a compromise of intended benefits. Like, who would like having a summer tire with improved ice traction that were now louder then heck the other 9 months out if the year; gas mileage asside.

Secondly, what makes you think advertising is always true. They probably sell nitrogen too. They are after people who want something for nothing and are too cheap to buy dedicated winter vs summer tires. Generally, gas mileage is secondary to improving the traction on a tire designed for safe winter driving.
They’re just throwing dung against the wall and hoping something sticks in the eye of the gullible buyer.

Many new tires these days are already sipped.

Why would you trust the high-school graduate at the tire store to know more about tire design then the engineers who designed the tire. If you don’t trust the engineers to build a quality tire for you (either with sipping or not)…then buy from a different manufacturer.

To go along with that thought, why would you trust a non highschool graduate which may be just as likely to work there, to sipe the tires on an Expedition you may drive over 100mph.

sipe the tires on an Expedition you may drive over 100mph.
Nothing altered. Just curious about the claims. The tire companies, I assume, would already have done this if it were effective. They already do a form of siping in their tread designs.

Since hospitals call in the middle of blizzards, I have Nordman SUV winter tires mounted on their own rims.
265 70R 17 Maximum pressure: 47 PSI! (Now at 44 PSI) Door post reads: 35 PSI
Surprisingly, they are “T” speed rating (118mph) which is the same as the OEM Bridgestone tires were.
The regular tires now are Michelin LTX M/S 2 P265 70R18 “T” rated Maximum 44PSI at 42 PSI

You can’t have your cake and eat it too. Tire siping could lead to increased fuel economy (probably undetectable) but it will also lead to less brake efficiency and road grip at the same time. The money you spend on “siping” would probably never be recovered through better fuel efficiency. Forget about it.

Where did you see someone claiming that siping can enhance fuel mileage? I always understood that it would decrease it slightly.

Siping is generally associated with the search for better snow & ice traction, and I have seen reports of testing that shows that it does that. (Here is a very brief snippet that says it increases ice/snow traction, but also increases stopping distance in wet/dry conditions:

I don’t go by the notion that one can’t improve on the engineers and manufacturers given specific purposes. In engineering and manufacturing there are lots and lots of things that have to be maximized, and plenty of tradeoffs. All possible things are not maximized at once. So if one has the very specific purpose of increasing ice/snow traction siping will probably help, but possibly at the expense of other things - like fuel economy, though I couldn’t say whether the effects would be measurable. I can say that it wouldn’t increase fuel economy.

Siping compromises the surface tread support. In other words, it will make the tire tread squirm on contact with the pavement. You will feel this in the car and it could be very unsettling. If the car is driven long distances on the highway, the heat built up in the tread surface will be greater than non-siped tires and could cause the tread to break off little pieces. The opposite of this is tire shaving; cutting away half of the tread depth to reduce tire squirm and heat buildup for street tires used for racing.

Siping, from a marketing viewpoint, would allow the use of tires not appropriate to drive in the ice and snow to be used instead of swapping to the correct winter tires. The engineer’s view is that it screws up his tire design. The cuts (or sipes) are theoretically small enough (IMHO) to wear away over a winter season. When spring comes, the tire acts as it did before the sipes were added.

As for a fuel mileage increase; no way. It would either have no effect or degrade the mileage.

It might be possible to find conflicting opinions on any topic on the internet, especially those that are in doubt.

You might want to look at the tread patterns of tires that are designed to result in less rolling resistance. Search words could be “fuel saving tires” or “low rolling resistance tires” to see if there is anything unique about the siping of these tires. I took a quick look at the Continental Touring Contact AS tires that are on my Chevrolet Cobalt XFE that is dedicated to good fuel mileage with a highway rating of 37 mpg which I can exceed in the summertime. These tires have some siping; not a lot and the siping is limited or closed in that it does not extend to the edges of each tread block. Tire Rack has a selection of low rolling resistance tires but I did not see mine in the Contintental selection.

My tires, by the way, have poor traction in the snow; not surprising that the design was compromised to more heavily favor another feature.

Race tires have minimal amount of tread. Excessive tread patterns, including siping would decrease the contact surface on dry road surfaces. Most driver’s mileage is on dry roads. I hear really good arguments from those who keep all season tires on their cars in winter while driving high mileage instead of going with winter tires for that exact reason. Now someone out there just might try traveling in a top heavy SUV on over inflated tires, possibly going over 100 mph that have been played around with by laborer whose training could very well have limited to this statement…" here is the on switch".

Most of my driving is on dry highways and interstates.
I wish I had a tire with a two-inch wide center band for the least rolling resistance.
Then if in any dirt, tread edges at the outsides of the tire would contact the material.

Siping is just putting more slots or cuts in tires. It was popular 30 years ago before tire designs changed. Don’t know what the purpose would be now outside of increasing sales. By the way, you do have millions of liability insurance right? Going 100 mph in the middle of the night and hit a bus or car load could end up pretty expensive. Flashing lights or not, accidents happen.

Going 100 mph in the middle of the night and hit a bus or car load could end up pretty expensive. Flashing lights or not, accidents happen.
Who would go 100 mph in the middle of the night? One could not see something in the road in time to avoid hitting it. Also there are deer and elk and horse and cow. Saw one moose! (The only time I was near a vehicle at high speed (105mph) was on a vacant interstate when a Corolla caught up to me and started to pass me in lane 2.)

Siping is a leftover from the days of bias poly tires when snow tires had large rubber blocks and tire technology predated the ability to mold in the additional slots. Unslotted large rubber blocks are terrible on ice.

Today’s tires are highly engineered in their design and the additional slots, which add edges and allow some additional tread block distortion to “bite” the ice, are designed into the tread on winter tires. In addition, modern tire carcasses flex more than the old bias ply tires, to allow the tread to lay flat on the road surface. That changes the whole effect of siping.

Siping tires not designed for the additional slots can result in additional heat buildup as well as reduced mileage due to the additional tread distortion that siping allows as well as reduced tire life. The heat buildup can result in premature tire failure.

I strongly recommend against siping in modern tires. If you want/need good winter traction, buy winter tires.

If you look at the tread of many winter tires, they have the same tread pattern as the all season versions, except they have a lot of siping. It does improve traction on ice. BUT, there are other differences in winter tires as well such as a rubber compound the remains more flexible in very cold weather. So siping all weather tires will help on ice, but it still will not bring them up to the level of a winter tire.

Bottom line, if you have a need for speed in the winter, get winter tires, but still watch that speed, there are limits and on ice, even with the best winter tires, those limits are pretty low.

You don’t want a tire with a two inch wide center band like a bicycle tire. If it helped, there would be tires, like bike tires, with them. The tire has only a hand print size patch of rubber in contact with the road at anyinstant in time. If a two inch wide surface is a solid band, you might as well have racing slicks.

Since this is the first time I’ve heard the word “siping,” I thought I would look it up. The definition is kind of funny.

It makes me wonder how they chose this term to describe a method of slicing your tire tread.

@Whitey, this days it was named after some dude who worked in a slaughterhouse and did it to his shoes:

I have no idea myself - it is a curious word.