Siping new tires ?

Well I picked up my 33x12.50 KM2's today. I live in Michigan and I am debating on siping my new tires. I mentioned it to my dad and he doesn't think it's a good idea but he has never heard of siping and seems to have this idea in his head that I'll be cutting grooves in the tire....

So, do I sipe them or just enjoy my new tires ? Any tips/tricks ect while on the topic ?

Siping it good for ice/street use, however your tread will chunk on rocks. It just a matter of grip vs. wear.

very good idea but if you do rough offroading only have the center lugs siped, avoid siping shoulder lugs d/t rocks chunking pieces off

I was only planning on doing the two inner rows of lugs and leaving the shoulder lugs alone. The jeep is my DD, so hard packed snow/ice was my thinking on this. From what I see it seems easy, just cut straight across the lug, I figured 3 cuts on the larger lugs and two on the smaller ones ? My lift hasn't arrived yet so I won't be running these for a couple more weeks. I'm actually going to mount them on my soft 8's tomorrow.

Oh, as for offroading, mostly woods/trails. Not a ton of rocks around me.

I know around my parts, quite a few tire shops do this for you with a special machine. I think you have america's tire or discount tire around you correct? If not call around to different tire shops around your area and ask if they provide this service. Usually its about 12-15 a tire.

I would stay away from trying to do it yourself IMHO.

Some places use a machine, others just use a hot knife, which is what I was going to do.

Yeah, the machine does a nicer job. $12 per here.

it can help streeted tires last longer because it helps dissipate heat better

Sipe them yourself, DON'T have the automated machines do it! they cut to deep and your tires will chunk really bad. By a cheap siper and only make the cut about 1/4" deep

Discount Tire here in Michigan does it for I think $10 per tire.

I have had my GY MTRs sipped and love it. I have also sipped the tires on my car and van. It helps alot on the snow and ice.

Because my MTRs are an Off-Road tire I had them do only 50% tread depth... AKA not all the way through the blocks... Only about a 1/4 inch deep... and only the center 50% of the tread width. I have not had any major chunks come off my tires.

For most of the time I keep the MTRs pretty full of air..AKA 35 PSI. This makes the bow a bit and keeps the corners off the road and they run on the sipped area of the tread.

For the Mounds I air down to about 12-18 and run them nice and soft.... I have even been known to make the the ride home at this PSI

For Silver Lake they run down to 6-8 PSI and I run around town this low there at Silver Lake. Then for the ride home back up to full pressure.


I have had my MTRs for 5 years and have about 10k on them... They still look good.

Oil Town XJ said:

Sipe them yourself, DON'T have the automated machines do it! they cut to deep and your tires will chunk really bad. By a cheap siper and only make the cut about 1/4" deep

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Not true. At least, not with the machine that Discount Tire uses. DT also only sipes the center third and leaves the should lugs alone, as has been recommended elsewhere here.

I had my 33x12.50 GY MT/Rs siped when I bought them 6 years ago, while my XJ was still my daily driver. I do recommend siping MT/Rs if you're going to be running any serious street time, it makes a significant difference in traction. And, after a week of wheeling in Moab, I didn't note any tread chunking.

Does siping help keep the road noise down vs an unsiped tire?

Explosive said:

Some places use a machine, others just use a hot knife, which is what I was going to do.

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A tire grooving tool is not the proper way to sipe a tire,you could do more damage than good.

i just did my 31" km1s.. used a razor blade/box cutter. takes about 40 minutes to do all 4 tires. i did it on my 33" km1s on the old xj and it made a noticeable difference in the ice/snow. i cut about 1/8" of an inch down.

ChiXJeff said:

Not true. At least, not with the machine that Discount Tire uses. DT also only sipes the center third and leaves the should lugs alone, as has been recommended elsewhere here.

I had my 33x12.50 GY MT/Rs siped when I bought them 6 years ago, while my XJ was still my daily driver. I do recommend siping MT/Rs if you're going to be running any serious street time, it makes a significant difference in traction. And, after a week of wheeling in Moab, I didn't note any tread chunking.

Click to expand...

I believe the sipping machine is adjustable depth and width.

Tires come in too many sizes to not be adjustable... So it is possible that somebody sipped a tire too deep that lead to chunking but... the store should be able to handle the request to only go 50% depth and the center 50% of the tread

Siping: http://www.discounttire.com/dtcs/tireSiping.dos