cordsig79

Ok, I did alot of searching last night because I have been frustrated finding a true Offroad tire.

I found a miata website that compares your OEM wheel with the different sized tires then cross referenced the tire sizes against the Offroad/maximum traction on tirerack.com. I found a ton of "mud tires" for the factory 17's.

Use the calculator to see what happens to your speedometer reading when you change the size of your tires and wheels. The graphic shows your stock tire selection in an outline overlaid on your new tire selection. It calculates that I will be at a 3.4% too fast, so when I am going 60, its really 58, etc.....

http://www.miata.net/garage/tirecalc.html

Now all in theory, I am running 235/65-17s per OEM. And i found a ton of 245/70R17 E tires that fit and attached them below.

Can these fit in theory, what else should I consider......again i think I found the optimal tire size in width and height with number of tires, the other options were too tall but same width.

Am I on to something where I can slap a slightly taller and wider tire on the 17 OEMs and then have a dedicated offroad set and maybe add a 5mml wheel spacer to not rub as much?

Because I would love to have my offroad ranch setup and then still have some summer/all season 20 inch black GTS wheels for regular setup.

Here are the 245/70-17 make and types in pics below:

1. BFGoodrich Mud-Terrain T/A KM2
2. Firestone Destination M/T
3. Goodyear Wrangler MT/R with Kevlar
4. Goodyear Wrangler DuraTrac

Feel free to make any other recs on tires too.

fnckr

Try this calculator instead. http://www.e90post.com/forums/forumdisplay.php?f=12

It provides even more useful info related to offset and width affecting the tires wall location versus the original tire.

Unless someone else has already posted their experience, you could take your current tires measurements in relation to the fenders and suspension components and utilize the calculator's results to determine the fit of the new tire.

DanaT

Here is a suggestion. I am not sure exactly what you want a mud tire for.

They suck in snow and are only really good for pure off-road. I had a Jeep Wrangler (YJ) with BFG All-Terrian ties on it (31") and a rear ARB locker. With the YJ I did this trail. http://www.traildamage.com/trails/index.php?id=4

I ran this trail http://hobojeepers.tripod.com/JennyCreek01.htm with a grand cherokee (WJ) with quadradrive (no lockers) with a 3 inch lift and 31" BFG A/T tires.

Really, unless you are into a lot of mud or rock crawling, I would use A/T tires. I think if you are into those, I Cayenne is not the right vehicle.

Now, I will give you a suggestion on a 245/65/17 A/T that works well.
http://www.yokohamatire.com/pdf/geoatpls2.pdf

Look for tire 245/65/R17 107H

Notice most of the tires end in "S". That one ends in "H". These are an H speed rated tire which was the highest speed A/T that I found.

-Dana

Cole

I wrote for a 4x4 mag for about 10 years and have tested a lot of off road tires, in a lot of conditions.

My favorite so far is the Goodyear MTR. "MTR" stands for "Maximum Traction. Reinforced." Not a "mud tire" as many think it is. GREAT tire off road. Super sticky on rocks, cleans mud and snow out well. More importantly they are quiet and sticky on the road. Which of course would be good for the Cayenne.

Personally, I would run the bigger tire size that is on the Transsyberia Rally Cayennes. From the looks of it they didn't do any fender mods the the Transsyberia models so the bigger tire will fit. Just set your tire choice on the in dash computer to the nearest size and realize that your speedo may be a touch off when you have them on. NO cop in their right mind is going to right you a ticket based on a 5mph fluctuation in the speedo. (and if you know it is there it is easy enough to compensate).

cordsig79

Thanks for the suggestions DanaT, I recently dumped my Wrangler after it couldnt maintain its coolant system so I lost a decent offroad vehicle.........and I only have a little bit longer till the Cayenne is paid off so i figured why not spruce up the factory 17s with off road tires....I am putting about 12k a year on the cayenne now so the reduced gas mileage from the tires and what nots wont bother me..........getting stuck does bother me.

Why do I consider offroad tires? I have hit some really slippery clay mud on unimproved roads and even with AT it slides tremendously without a good toothy tire. The sidewalls not having grip has been an issue too.....eg: camping, duck hunting and cutting through pastures is where the need for grip and rip comes in handy..

And capping my base 6er at 99 for the speed rating.....not a concern either. I drive 10-16 miles round trip in Austin for work now and its all on Westlake Blvd in the hilly scenic part where you rarely can exceed 25-30 mph.

Maybe Ill just surf Craigslist for a used pair of offroad tires off a jeep in that size and then use them for a winter/offroad sled setup.......that yoko tire does look good for dual purpose.

All input is helpful, Cole, I found goodyear MTR 245/70/17s with Kevlar on special for about 688 at tirerack.........that pic is of the 18's..all nice!!

Thanks guys, all good suggestions.

Cole

You will find lots more options in 17" Most pickups come with 17s and most of the offroad community is going to 17s.

I ran them on my last two Wranglers and the truck I built just to clean up trails.

More pics just for the fun of it since there are former Jeep guys on the thread.


The TJ with 37s on a 17" wheel.



The JK Rubicon with 17" wheels. (also came stock with 17" wheels)



I built this old Crew Cab 1 ton to do trail clean up and maintenance here in Colorado. 37s on 17s again.




SOOOOOOO tempeted to build a trail ready CTT

cordsig79

I just picked up 4 unused OEM 17 with TPMs FOR 200 BUCKS. Im about to go outside and pressure wash them, sand them, then spray them with a matte or satin black finish..........diidnt you say you just used satin Dupont spray cans? about 2-3 for 7 bucks correct?

yeldogt

Cole -- that is cool stuff !!


I have done a lot of crazy stuff in Africa using Land Rovers -- but the rocks ...WOW

Cole

I used Duplicolor wheel paint. Should be able to find it at any auto parts store. I lightly stuffed the wheels with 600 grit and painted.

cordsig79

mocked up one and compared it.........

I ended up getting Krylon, Flat Black Camoflague paint.........

Never gritted it up but I did clean and degrease heavily after powerwash.

2 wheels side by side

Cole

Looks pretty cool.

cordsig79

17 OEM Porsche Wheels 265/65/17 AT, biggest you can do with Steel.......If you go 18 I think the tire options are better but less sidewall.

cordsig79

oopss forgot these

cordsig79

I bought Hankook ATM 245/65/17's today. The larger tires steel belts broke? Thats the 3rd set of tires it has occured on in the Cayenne.

I went below the 270/70/17's because my gas mileage had dropped to 14mpg.

I hope I can average in the city again around 18 plus and 22 plus on the highway now that I am near 235/65-17 OEM spec.

I still have the summer 22's just not had an itch to put them on.

Cole

Keep in mind that with a larger tire you will travel further than your odometer is indicating, giving the false impression of worse fuel mileage.