09-21-2015, 02:17 PM
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- Jeep Grand Cherokee ZJ 1993 to 1998 Tires General Information and Specs
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10-24-2016, 02:27 PM
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Year: 1993 YJ Wrangler
Engine: 4.0 I6
I thought the largest stock size on any XJ was 225. That being said, the pressure on the door says 33 PSI for the 215/75r15 size that it came with. Don't know that I'd go higher with a larger tire.
10-24-2016, 02:34 PM
No, I don't lick fish.
10-24-2016, 04:22 PM
No, I don't lick fish.
I would start at what it says on the door and work down. Larger tires require less air than smaller tires, so you know you're not going to need more than the OEM pressure.
10-24-2016, 04:29 PM
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Year: 1998
Model: Cherokee
Engine: 4.0L
10-24-2016, 09:37 PM
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95 XJ SE, 4.0, auto, 4 door, 162k miles. I stumbled on to a discussion here that is already talking about a topic I needed to find. I just up-sized tires from factory sized of 215 75 15 (27.69" dia) to 235 75 15 (28.87" dia).
Per my GPS, my speedo was dead on with the 215 tires. With the 235 tires, there's only a slight difference. With the cruise set at at 70, the GPS shows anywhere from 70.8 to 71.2 mph. My question is, with this minor a difference, is there any need to correct with a different speedo gear? I don't notice much difference in shifting or power. I do notice some lack of power on hills when in OD, but not drastic. Am I missing some level of performance or doing any harm to the transmission by leaving it "as-is" with the taller tires? Seems pretty minor from all observations so far.
Per my GPS, my speedo was dead on with the 215 tires. With the 235 tires, there's only a slight difference. With the cruise set at at 70, the GPS shows anywhere from 70.8 to 71.2 mph. My question is, with this minor a difference, is there any need to correct with a different speedo gear? I don't notice much difference in shifting or power. I do notice some lack of power on hills when in OD, but not drastic. Am I missing some level of performance or doing any harm to the transmission by leaving it "as-is" with the taller tires? Seems pretty minor from all observations so far.
10-24-2016, 09:47 PM
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Year: 1999
Model: Cherokee
Engine: 4.0
95 XJ SE, 4.0, auto, 4 door, 162k miles. I stumbled on to a discussion here that is already talking about a topic I needed to find. I just up-sized tires from factory sized of 215 75 15 (27.69" dia) to 235 75 15 (28.87" dia).
Per my GPS, my speedo was dead on with the 215 tires. With the 235 tires, there's only a slight difference. With the cruise set at at 70, the GPS shows anywhere from 70.8 to 71.2 mph. My question is, with this minor a difference, is there any need to correct with a different speedo gear? I don't notice much difference in shifting or power. I do notice some lack of power on hills when in OD, but not drastic. Am I missing some level of performance or doing any harm to the transmission by leaving it "as-is" with the taller tires? Seems pretty minor from all observations so far.
Per my GPS, my speedo was dead on with the 215 tires. With the 235 tires, there's only a slight difference. With the cruise set at at 70, the GPS shows anywhere from 70.8 to 71.2 mph. My question is, with this minor a difference, is there any need to correct with a different speedo gear? I don't notice much difference in shifting or power. I do notice some lack of power on hills when in OD, but not drastic. Am I missing some level of performance or doing any harm to the transmission by leaving it "as-is" with the taller tires? Seems pretty minor from all observations so far.
10-24-2016, 10:58 PM
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Year: 1993 YJ Wrangler
Engine: 4.0 I6
Remus, there's no need to ever let that cross your mind again with such a minor change.
The difference between 215/75R15 and 235/75R15 follows.
Width:
235 - 215 = 20mm. The 235 is 2cm wider
Height:
Both have an aspect ratio of 75, so the sidewall is 75% of the width.
215 · 0.75 = 161.25mm.
That's the height of the sidewall on each side of the wheel, so we double it in order to count the top and bottom of the tire.
161.25 · 2 = 322.5mm.
322.5 ÷ 10 = 32.25cm
32.25cm ÷ 2.54cm/in = 12.7 inches
12.7in + 15in wheel = 27.7 inch tall tire
If we repeat all that math figuring out the height of the 235/75R15, we end up with 28.9 inches.
You're looking at a difference of 1.2 inches overall. Because the tire mounts to the axle at the center, that means the Jeep sits 0.6" higher, and the tire goes 0.6" higher into the wheel well.
To put it in perspective, that increase in height could be lost by wearing down the tread on your new, taller tires and letting the PSI drop a little more than it should. It's pretty insignificant when it comes to power.
The difference between 215/75R15 and 235/75R15 follows.
Width:
235 - 215 = 20mm. The 235 is 2cm wider
Height:
Both have an aspect ratio of 75, so the sidewall is 75% of the width.
215 · 0.75 = 161.25mm.
That's the height of the sidewall on each side of the wheel, so we double it in order to count the top and bottom of the tire.
161.25 · 2 = 322.5mm.
322.5 ÷ 10 = 32.25cm
32.25cm ÷ 2.54cm/in = 12.7 inches
12.7in + 15in wheel = 27.7 inch tall tire
If we repeat all that math figuring out the height of the 235/75R15, we end up with 28.9 inches.
You're looking at a difference of 1.2 inches overall. Because the tire mounts to the axle at the center, that means the Jeep sits 0.6" higher, and the tire goes 0.6" higher into the wheel well.
To put it in perspective, that increase in height could be lost by wearing down the tread on your new, taller tires and letting the PSI drop a little more than it should. It's pretty insignificant when it comes to power.
10-25-2016, 08:49 PM
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Model: Cherokee
Need help with 8" lift
I have a 2001 xj with 3' spacers in the front and 2.5" shackles in the back. Im adding 4.5" coil springs next week for a total of about 8", 7" after the coils settle of coarse. My question is what is the minimum/ most important things needed as far as drop brackets, shock extensions, etc? I am 17 and do not have the money to buy everything immediatly 
so what do i absolutely need for the xj to function correctly and what can wait a couple days before modifying.
so what do i absolutely need for the xj to function correctly and what can wait a couple days before modifying.
10-25-2016, 08:59 PM
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Year: 1999
Model: Cherokee
Engine: 4.0
I have a 2001 xj with 3' spacers in the front and 2.5" shackles in the back. Im adding 4.5" coil springs next week for a total of about 8", 7" after the coils settle of coarse. My question is what is the minimum/ most important things needed as far as drop brackets, shock extensions, etc? I am 17 and do not have the money to buy everything immediatly so what do i absolutely need for the xj to function correctly and what can wait a couple days before modifying.
so what do i absolutely need for the xj to function correctly and what can wait a couple days before modifying.I got a little upset there for a bit. You are not only putting yourself at risk, but others as well with this damn crazy plan
10-25-2016, 09:46 PM
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Year: 1998
Model: Cherokee
Engine: 4.0
new to Cherokees and was wondering if i get a 3in rough country lift and some bushwhacker cut to fit fender flares will my 98 xj fit 33x12.5 r 15?
10-25-2016, 10:32 PM
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Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
I have a 2001 xj with 3' spacers in the front and 2.5" shackles in the back. Im adding 4.5" coil springs next week for a total of about 8", 7" after the coils settle of coarse. My question is what is the minimum/ most important things needed as far as drop brackets, shock extensions, etc? I am 17 and do not have the money to buy everything immediatly so what do i absolutely need for the xj to function correctly and what can wait a couple days before modifying.
so what do i absolutely need for the xj to function correctly and what can wait a couple days before modifying.
10-25-2016, 10:33 PM
Herp Derp Jerp
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Year: 1999
Model: Cherokee
Engine: 4.0L OBD-II
Take a look at another lift though. Zone makes a really quality 3" kit.
10-25-2016, 11:36 PM
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Year: 1993 YJ Wrangler
Engine: 4.0 I6