255 vs 225 or 245 vs 225 for 99 Jeep XJ ?!?!?!

[WorleyGuy]

Howdy!

I want a tire that is excellent in rain and dry weather. Where I live it does not snow that much, so decent traction in snow is okay.

I have Michellen LTX M/S 225/75/R15 on it now from previous owner.

Other than tire rub against the trailer arm, what concerns should I have about going from 225 to a 245 or a 255?

All thoughts are welcomed.

WorleyGuy

[email protected]

 

[Gary Allan]

I like 235/75r15 for this application. It's what I put on my son's 00 XJ and my 02 TJ SE. It's available in a LTX M/S

You can stop rubbing on turns (I assume that's what you're referring too

) by adjusting the turning stops ..it should, however, be unnecessary with the 235/75 on 15x7" OEM wheels.

 

[Greaser]

quote:

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Originally posted by Gary Allan:
I like 235/75r15 for this application. It's what I put on my son's 00 XJ and my 02 TJ SE. It's available in a LTX M/S

You can stop rubbing on turns (I assume that's what you're referring too

) by adjusting the turning stops ..it should, however, be unnecessary with the 235/75 on 15x7" OEM wheels.

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Any big change in power/gas mileage ?

 

[TheTanSedan]

Ran KUMHO Ecsta STZ 255/65-16 on optional JEEP rims on our 2001 60th Anniversary XJ.

See Tire Rack for above tire and reviews of same, I posted twice with quite a bit of data. No snow use, but all performance beyond superb!!!

2 or more years and about 50,000 miles, tread was still close to 50%.

 

[Gary Allan]

quote:

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Any big change in power/gas mileage ?

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My son's XJ appears to be geared a little high ..but unless you're above 65 mph with 4 people in the thing it will pull nicely with these tires. The mileage appears unchanged. These are basically 30" tires without the added mass (30" being 28.5").

On my SE ..you don't perceive any power loss ..but that's because you're using more pedal on the highway ..and you have a lot more rotating mass. With the stock 205's on there, if you let off the gas at anything over 60, it felt like you opened a parachute behind you. Now it rides much better and is far more stable. It does reduce my highway mileage to about 17.5 ...when the stock yielded about 20. I can get 20 mpg with these tires in "rolling hills" ..but aerodynamics appears to wreak havoc with it on highway driving. If I'm doing 55 or less ..then it's okay. Running with the pack ...it's 17.5.

The only thing you need to figure out is which speedo gear to put in the 231 transfer case to get your speedo reading correctly. They're cheap ($12-15) and are easy to change out.

Here's a good applet : just plug in the numbers

and here's how you change it: Cherokee America

The part # for speedo gears are 520676XX (xx being the tooth count of the gear). Any further "fine tuning" can be done by the dealer with the DRBII scanner tool. They can dial in a % of the pulse generation from the sender attached to the gear.