Category Archives: Wheels & Tires

Under Pressure

After driving on my freshly aired down tires for about a month and a few tanks of gas, I’ve decided to go back to the manufacturers suggested higher pressure of 37psi.  When I first dropped down the pressure, I thought that the Jeep felt a little sluggish.  Initially, I figured that was all in my head.  But after tracking my fuel economy, I noticed a 1-2 mpg drop despite similar driving conditions.  Sure, the ride was a little more cushy, but not enough to be worth the additional fuel cost.  I think I’ll keep the tires topped off around town or on the highway and save the lower pressures for strictly off road use.  Like I said, take the chalk test with a grain of salt and in the end, make up your own mind as to what’s right for your and your specific set up.

And here’s David Bowie’s Under Pressure, because let’s face it… it’s been stuck in your head since you read the post title.

The Chalk Test

The chalk test is a simple and inexpensive way to make sure you aren’t running too little or too much pressure in your tires.  As everyone out there will tell you, use your common sense here.  If the test tells you to run at 1psi, there’s probably something wrong.  You also have to take into account the width of your tire vs. the width of your wheel, so keep all that in mind when performing this test.

To get started, all you really need is a flat paved area, some side walk chalk, and your tire pressure gauge.  I generally run my tire pressure a little on the high side, so I started off at 37 psi as I chalked up my tire for the first pass.
37-ChalkedI drove straight forward a few feet, then a few more feet, then a few more feet looking for a pattern as the chalk wore off.  If you have a GoProHero 3 or 3+ that you can aim at the tire while using a wifi connection to monitor what it displays, that makes life soooo much easier.  Instead of pulling forward a few feet, stopping then getting out and then looking at your tire, you can just glance at the screen while you inch your Jeep forward.  I bet you’ll never guess when I figured that trick out.  (hint: It’s way after I was done!)
37-ResultsAt 37 psi (shown above), the tire is over inflated since there’s no chalk left on the center of the treads but there is plenty on the edges.  Break out your trusty pressure gauge, air down, re-chalk and repeat.  Next stop, 34 psi.
34-ResultsNope, 34 psi (shown above) is still a little too much.  However, I am heading in the right direction slowly but surely.
32-Results32 psi (shown above) is still too much.
28-Results28 psi (shown above)… almost there.
26-ResultsWinner Winner Chicken Dinner26 psi (above) looks to be just about spot on.  See how the chalk wore evenly across the entire tire?  As far as the tread is concerned, that should provide even wear over the life of the tire.  Personally, I get a little nervous running a tire at pressure that low but based on everything I’ve read and heard and everyone I’ve spoken with, I’m right on the money.  If nothing else, the ride is a whole lot smoother with the pressure dropped.

Wheel Repair

I’ll be the first to admit it when my ‘good idea’ doesn’t go as planned.  So, allow me to introduce you to my latest idea…  Wheel repair.  One of the design features I like about my wheel is the machined metal lip that I didn’t think would show rock rash very much.  My plan has been working great until this most recent off-road trip where I really gaffled a couple of my wheels.  I watched a couple videos on wheel repair and picked out one of my wheels without too much damage to give it a try.  Look for the damage on the lip at about the 10 o’clock position.

 

WheelDamage1Using a variable speed Dremel with 3 grits of sanding bits, I started with the finest grit at the slowest speed to see how the metal would react.  If you know what you are doing (I didn’t) you want to start with the heaviest grit first and then work towards the lightest to smooth everything out.

 

WheelDamage2This picture looks like it shows fantastic results!  But, the truth is that while I was able to smooth out the metal (feels great to the touch) cosmetically the wheel damage looks just as bad.  Only in a different way.  There’s no easy way to create a matching machined pattern while grinding off damage with a dremel.  A painted wheel… yes.  But machined metal is beyond my skill level with a Dremel at this point.

If I decide to swap out my wheels when I bump up to 37’s, I’m going to think long and hard on a set of ZX wheels from Level 8.  That’s a great looking set of wheels but the really cool feature is that they offer a protective rock guard that you can attach to the wheel for off-roading.  The ring, made of a high impact polymer attaches to the lip of the wheel to take rock rash so your wheel doesn’t.  REALLY effing clever!

Another set of lugs?

When I swapped out my Rubi wheels for a set of Dick Cepek Torques, I also swapped out my lugs for a set of black locks.  There was nothing wrong with my OEM lugs and Mopar wheel locks, I just like the look of black lugs on black wheels.  You know, matchy matchy!  I did absolutely zero research when I picked out the lugs, instead I simply asked the shop selling me the wheels to toss in a set of black lugs and called it a day.  What they sent me was a set of ProComp lugs that were rusted a month later (in the middle of summer?).  I thought this must be a defective set to fail so quickly so I grabbed the phone and gave ProComp a call to let them know what happened.  ProComp kindly tossed a new set in the mail which I promptly installed as soon as they arrived.

Well, fast forward to today with the brutal winter finally leaving us and I’m sure you can guess what my lugs look like.  I can see the rust at 20 yards!  And that just won’t do.  After a bit of researching, I ponied up the cash for a set of McGard locks to replace this rusted out mess.

ImageWhen you unbox the McGard 84562BK, you can tell they put a lot of care in their product.  Each and every lug is individually wrapped, the locks are individually sealed in little bags, and the warranty/replacement info comes in a thick plastic pouch for safe keeping.  The parts and materials feel top notch as they should for wheel lugs at this price point.  The next image shows a comparison of my current ProComp lug/lock on top to the McGard on bottom.  I can’t believe those ProComps are less than 9 months old!  They look like they belong in a junk yard.

ImageThe locks/lugs are beautiful, but unfortunately this story doesn’t end here.  The McGards are a FAT, FAT lug and based on the design of my wheel, I can just barely fit the lug onto the wheel and finger tighten them.  Even a thin walled socket can’t do the trick.  Damn.  I so badly wanted these to work.

ImageI didn’t spend long at the drawing board before I swapped over to my second choice, a spline drive lock/lug set from Gorilla, part # 21184BCD.  The unboxing looks pretty good and the test fit is pretty good.  I’m finally supposed to see the sun this weekend, so it’ll be time to clean everything up and swap in the new hardware.

I’m a firm believer of the ‘buy it right or buy it twice’ thought process, but I really screwed the pooch on this wheel lock issue.

  1. Stock Wheel Lugs
  2. Mopar Wheel Locks
  3. ProComp Black Lug/Lock, set 1
  4. ProComp Black Lug/Lock, set 2
  5. McGard 84562BK
  6. Gorilla 21184BCD

Those ProComp lugs… They are going to the metal scrap yard in the sky.  If you need a set of black lugs, just don’t.  Look somewhere else.  ProComp makes many great products, but black wheel locks just aren’t one of them.

Speedo

After slapping on the new tires, I needed to recalibrate my speedo. I know most folks use a FlashCal or a ProCal, both of which are fantastic devices, but earlier this year I picked up an Aeroforce Tech Interceptor gauge to go in the center of my sPOD. This gauge also features two way communications, a feature that I have yet to take advantage of until now. I flipped through the internets and found an older thread, but still a solid read on JK Forum that gave a good description on how to set your speedo for your new tire size. The OP says “The Tire Size is entered based upon circumference in millimeters. Here’s a little chart to make it easier: (You should round the number e.g. 2656.8 = 02657)

Image This chart is from the post referenced above. I did not make it.

Starting with that calculation pic, I went to the garage to measure the circumference of my tires using a very scientific method… I wrapped a string around my spare to get 2788 mm. When I tried using that setting, my speedo was waaaaaaaaaaay off. On a side note, for those of us with OEM NAV’s, the speedo on the instrument panel and the speed display on the NAV come from the same source. One isn’t a GPS based number.

After quite a bit of trial and error testing, the perfect measurement to get the speedo to line up with the GPS was actually 2643 mm (or the same revs as a 33.125″ tall tire). Either there’s a been a change to how the 2013’s calculate speed and distance (possible, but unlikely) or a tire under weight actually does compress THAT much. Wow! Did I just learn something new?

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From the ground up, the half way point (center of the center cap) is at 17 3/8’s.  That translates into a (17.375 * 2) 34.75″ true height.  Sooo maybe my math is wonky somewhere or I have no clue how it’s properly calculated.  The important thing is that the speedo is dead on accurate and so is the odo.  I’m just going to attribute the need to use 2643mm to umm… gremlins.  Yup, gremlins.

Stop… Tire Time!

From the minute I picked up my JK, I always knew deep down inside that I would end up on a larger tire. Oh sure, I tried to pretend that the stock size would be enough for me. But that fat bottomed girl kept reminding me just how long she is when it came to getting up, up, and over obstacles. A scraaaaaaaape here and there to let me know the skid plates are working also makes for a fine subtle hint. My research started well over 7 months ago with a simple spread sheet. As much of my research has been known to do, it just kept growing and growing. More metrics, more descriptions, more options. I became obsessed with true heights. Every ounce needed to be calculated. I had to COLLECT ALL THE DATA!

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With data in hand, I started thinking about what I wanted to do and what I could do. 40’s? Nah, too big. I wouldn’t fit in my garage. Do I jump into 37’s? They do look awfully nice on a 4 door (great proportions). But, I can’t fit them with out trimming or swapping out fenders. Ok, but I can’t change my fender set up with my current bumper, so I’d have to swap that out for a mid or stubby. And while I’m swapping the bumper, I might as well change my winch line. And I should probably re-gear if I’m gonna do all that… Maybe now isn’t the time for 37’s. What about 35’s? That’s a nice size, not too big, not too small. Juuust right.

But, not all 35’s are created equal. Some folks claim 315/70r17 is a 35, others say only a 35×12.50r17 is a proper 35. With 35’s as the goal, I whittled away at a wishlist. Before you ask, yes I know I’m comparing MT’s and AT’s. I just put them all in one big pot to fight it out! The Ideal tire would score perfectly on all of the following (in no particular order):

Criteria

  • Highway Ride – Let’s be honest, even if I wheel every weekend, these tires will still clock more miles on the highway than on the trails. I’d like a quiet comfortable ride on the road.
  • On road handling in all weather conditions – This is key. A great mud tire that can’t actually get me (and my family) safely to the trail or anywhere else is pretty useless to me.
  • Price – I’d still like to be able to afford to eat after I buy a set of tires.
  • Sidewall Strength – I don’t think this needs explaining.
  • Tread Pattern – They need to be able to get through/over whatever I throw at them.
  • True height – Why, why, why do all the manufacturers offer different true sizes of 35×12.50? If it’s a 35, just stamp a 35″ tire!
  • Weight – I know my JK isn’t a hot rod or a fuel sipper, but increased rotational weight is huge a power and MPG drain.

The many, the disqualified!

  • BFG All-Terrain T/A KO – Excellent on road qualities, but mud is this tires kryptonite.
  • Cooper Discoverer STT – This has a nice aggressive tread pattern, a great price, is not too heavy, and doesn’t howl on the road. It almost made it into the finale.
  • Dick Cepek Crusher – Just a little too heavy for the size and I could only find it in metric for a 35.
  • Dick Cepek Fun Country – Great tire that competes with the Duratrac, but has just recently been discontinued.
  • Falken Wild Peak AT – The tread is a bit weak here, but they are a great price and the only AT to offer a 50k mile warranty.
  • General Grabber (Red Letter) – I saw these on a buddy’s JK. They have a nice tread pattern, but are too heavy.
  • General Grabber AT2 – Good true height, decent weight, but there’s just not enough meat in the tread.
  • Goodyear Wrangler MT/R with Kevlar – Love the Kevlar side walls, the tread is nice and meaty, but I kept hearing about how loud these tires are on the road.
  • Hankook Dynapro MT – This tire took first place in 4wheelers mud tire shoot out, but they were a little pricy for what you got imho.
  • Kumho Road Venture MT KL71 – The price is great, but they are pretty damn heavy.
  • Micky Thompson Baja MTZ – The tread on this tire is nice, the weight is good, but during my research I found the tire to run a little on the small side when it comes to true height.
  • Nitto Mud Grappler – Meaty tread, strong sidewall, reasonable price, but they are just too loud on the highway.
  • Nitto Trail Grappler – Great tread, strong sidewall, reasonable price, but they are just too damn heavy.
  • ProComp Xtreme MT2 – The 40k mile warranty is nice and they do have an aggressive tread pattern, but I’m still on the fence on ProComp parts. They haven’t wow’d me yet.
  • Toyo Open Country AT II – 80lbs for an AT tire? That’s all the info I need to kick this tire off the list.
  • Toyo Open Country MT – Great tread and price, but at 83 lbs/tire, this is the heaviest 35 on the entire list. And possibly one of the heaviest 35’s out there.
  • Yokohama Geolander M/T Plus – The lightest of the 35’s but also one of the smallest true heights. Mixed reviews and the true height cost this tire a spot.

Finalists:
BFG Mud-Terrain T/A KM2 – My stock tires are the BFG KM’s and I really love them. The KM2’s are the same style tread, offer a very good highway ride and a strong Kevlar sidewall. However, the highest price combined with low scoring on ice traction cut this tire from my list. The weight is pretty good and they are the front runners for 37’s if/when I go that route.
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Dick Cepek FC II – Replacing the DC Fun country is the FC-II and is a pretty aggressive AT tire. There’s a lot of engineering and science that went into that tread. Nice highway ride, good snow/ice traction, and a reasonable price kept this tire competitive.
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Goodyear Wrangler DuraTrac – I have yet to meet a person that’s running a duratrac that doesn’t like it. Great snow/ice/mud/highway ride, the best weight and the price isn’t bad either. I just wish it was a little bigger. You hear that GoodYear? Make this in a true 35″ or a 37″ and I bet you’ll get more than a few sales out of it. Small true height and a slightly weaker sidewall made this tire my runner up.
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Winner:
Dick Cepek Mud Country – The DC Mud Country offers a comfortable highway ride, very aggressive tread that’s surprisingly quiet, about average weight, an M+S designation, a strong side wall, close to a 35″ true height, and a pretty reasonable price. Is this tire perfect at everything like I had hoped? Nope. But it is pretty damn good at all of it. Over the last 2,000 miles, I’ve tossed wet and dry pavement at it, DEEP snow, sleet, ice, and mud. The tires have performed extremely well on all of it.
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They especially excel at deep snow where I spent a good bit of time only needing 2wd to get around while others needed 4H or 4L. They were recently at Rausch Creek and they performed well. They offered nice sidewall flex when aired down to 19 psi (I’m sure they could easily go lower) and provided great traction for hill climbs and all the snowy trails. Yes, I did get stuck once but that’s my own fault and no dig on the tires. On the highway for the first 200 miles, they were Lexus quite (not kidding). After about 250 miles, they did get a little louder. I can hear them, but only when I turn off the radio, and engage the clutch. The in cab noise clocks in at 72 dB with all the windows up & the hard top on.

One of the best recommendations I can give a product is the following: Would I buy it again? The answer here is yes, yes I would.

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17’s on my feets, oh yeah!

When shopping for new wheels, I started out by oohing and aahing at all the shiny things that were on the covers of my Jeep porn mags [cough]Quadratec Catalog[cough]. ‘Man, those 20’s are hot!‘ I thought to myself. And yeah, they look good now but with absolutely no offset they are gonna end up beaten to hell after the first time I take them out on trail. And so my criteria began to shape itself. I knew I wanted something with an offset and I also knew that down the road I was planning on lifting my JKUR and running a larger tire. Larger tires can get crazy heavy, so looking for a light weight but sturdy wheel was important too. Ok, since we are talking about keeping the weight down so that my Jeep doesn’t get bogged down at highway speeds (I gave up 6th gear in my last Jeep thank you!) it might be wise to take a minute to check the tire weights (& prices) depending on the sizes.

Let’s say I wanted to run a 35″ tire on a 20″ wheel later on when I got a lift. Using a Goodyear MT/R tire as my example that means my tire weight goes up to 71lbs and my wheel weight goes up to 42 freakin pounds! (an increase of approx 40lbs/wheel??) However, if I stick to a 17″ wheel, my tire weight only jumps to 64lbs for the same over all diameter. Not to mention a 35″ tire on a 17″ wheel is over $100 cheaper/tire! With a spreadsheet on hand tracking weights, sizes, & costs I further narrowed my search down to a 17″ wheel. Which conveniently meant that I could get it NOW since I have tires mounted on a 17″ wheel set up. Woot! The kind folks at 877-iamJeep informed me (incorrectly it turns out!) that the OEM Rubi wheels weigh in at 27lbs each. So, I’m hunting a 17″ wheel with an offset, in an 8.5″ width that weighs less than 27 lbs., and has either a flat black or argent finish. The finalists are…

AEV Pintler Wheel in Argent. It’s a little on the heavy side (27lbs), especially if you add bead locks. I do really like the recessed valve stem protection and they look fantastic!

AEV Pintler

ProComp 8188 Wheel in black. It’s the featherweight of the bunch at 24lbs/wheel, I like the black design and the offset but I can see those shiny metal accents on the lip getting chewed off by the first rock they think about meeting. Will it work with my OEM TPMS sensors?

ProComp 8188

Dick Cepek DC Torque Alloy Wheel in Black. Not the lightest of the group, but pretty close. I like the depth and the design and they are designed to work effortlessly with the OEM TPMS sensors & the price won’t break the bank.

DC Torque

If you’ve glanced at my avatar once, you already know that the winner is the Dick Cepek DC Torque Alloy Wheel in Black! I think these wheels look amazing on the billet silver, almost like they were designed to be there in the first place. I’m disappointed that the folks at 877-iamJeep incorrectly told me the OEM wheel weight as I was looking forward to shaving off a few pounds of rotational weight, but so it goes. OEM Rubicon Wheel is 24.7 lbs./wheel, the DC Torque weighs in at 25.1 lbs./wheel. So, it’s really a wash for weight differences of that size. Over all, I’m very happy with the look. Not too blingy, I think it’ll survive the trails nicely, and they’ll look great wrapped in a set of 35’s (37’s?) one day.

KachowFront

KachowRear