Wondering About 285s.....
09-04-2008, 09:52 PM
#1
JK Jedi
Thread Starter
Wondering About 285s.....
For those of you with 285 75 16s on Unlimiteds with 3.73s and an auto, how bad is the power loss? I have 245s now. I'm looking at both 265s and 285s. I really want the 285s, but I do NOT plan on regearing. EVER. So, honestly, how bad a power loss can I expect from 285s? Thanks.
09-04-2008, 10:25 PM
#2
JK Super Freak
285/75/16's are just 33's.
32's are a stock size...you you are barely off the stock spec anyway.
IE: the 285's will be 3% over stock.
I'd go to a 305/70/16...about the same 33" diameter, but better flotation and braking, better lateral acceleration, and better rock, dirt, mud and sand traction.
The 285's MIGHT need spacers...the 305's WOULD need spacers...
...But the spacers widen your stance, add cornering and off camber stability, etc.
....So that's a good thing.
32's are a stock size...you you are barely off the stock spec anyway.
IE: the 285's will be 3% over stock.
I'd go to a 305/70/16...about the same 33" diameter, but better flotation and braking, better lateral acceleration, and better rock, dirt, mud and sand traction.
The 285's MIGHT need spacers...the 305's WOULD need spacers...
...But the spacers widen your stance, add cornering and off camber stability, etc.
....So that's a good thing.
09-04-2008, 11:31 PM
#3
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Around town it's ok. I can't stand it on the hwy. Always coming out of overdrive so I've started just leaving it off. The slightest incline will knock it out too. I don't have cruise control so I don't know if that will help or not. Now, I have *not* had it reprogrammed for the new tire size. That may help with the tranny shift points. However, I'm done tiptoeing around what I need to do so off to the shop it goes.
So I am regearing next week. I've had it like this for about 8-months. Shoot me now.
So I am regearing next week. I've had it like this for about 8-months. Shoot me now.
09-05-2008, 01:01 AM
#4
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285/75/16's are just 33's.
32's are a stock size...you you are barely off the stock spec anyway.
IE: the 285's will be 3% over stock.
I'd go to a 305/70/16...about the same 33" diameter, but better flotation and braking, better lateral acceleration, and better rock, dirt, mud and sand traction.
The 285's MIGHT need spacers...the 305's WOULD need spacers...
...But the spacers widen your stance, add cornering and off camber stability, etc.
....So that's a good thing.
32's are a stock size...you you are barely off the stock spec anyway.
IE: the 285's will be 3% over stock.
I'd go to a 305/70/16...about the same 33" diameter, but better flotation and braking, better lateral acceleration, and better rock, dirt, mud and sand traction.
The 285's MIGHT need spacers...the 305's WOULD need spacers...
...But the spacers widen your stance, add cornering and off camber stability, etc.
....So that's a good thing.
09-05-2008, 02:09 AM
#5
JK Super Freak
I'm running 285/75r16s on the stock steelies. I noticed a slight loss of power that was most noticable at freeway speeds. Before the lift, I was getting rubbing up front at full lock. They rub on the rear sway bar as well. The small lift took care of the rubbing. (2.5 BB)
I feel the small loss of power on the freeway is acceptable since the capability of the Jeep off road has improved exponentially since the addition of these tires.
I feel the small loss of power on the freeway is acceptable since the capability of the Jeep off road has improved exponentially since the addition of these tires.
09-05-2008, 03:44 AM
#6
JK Super Freak
Yeah - well, as noted above, the 305's rubbed, and as expected, they rubbed on turns in front.
A thing to remember on a forum...some of the people have higher performance expectations than others...IE: Many were unhappy with the stock set-up...so giving up ANYTHING, let alone a mere 3%, is going to make them nutz.
Personally, for the mucho dinero it costs to re-gear...I'd live with the 3% loss....its not like you never get where you're going or anything.
Of course, I have the 6 speed. People who forgot how to shift for themselves and have torque converter slippage and so forth, and can't re-gear on the fly with the shift lever...suffer a bit more if the automagic thing they paid to shift for them gets confused when they don't re-program it.
The vast majority of drivers are fine with as small an increase as we're talking about...the few more demanding souls will find it intolerable to drive even the stock set-up, etc....and bitch proportionally....and typically, more often.
None of the company trucks get re-geared...the mpg is great with the slightly deeper overdrives the larger tires provide...when the increase in tire size is proportional to what we are talking about here.
Enjoy!
A thing to remember on a forum...some of the people have higher performance expectations than others...IE: Many were unhappy with the stock set-up...so giving up ANYTHING, let alone a mere 3%, is going to make them nutz.
Personally, for the mucho dinero it costs to re-gear...I'd live with the 3% loss....its not like you never get where you're going or anything.
Of course, I have the 6 speed. People who forgot how to shift for themselves and have torque converter slippage and so forth, and can't re-gear on the fly with the shift lever...suffer a bit more if the automagic thing they paid to shift for them gets confused when they don't re-program it.
The vast majority of drivers are fine with as small an increase as we're talking about...the few more demanding souls will find it intolerable to drive even the stock set-up, etc....and bitch proportionally....and typically, more often.
None of the company trucks get re-geared...the mpg is great with the slightly deeper overdrives the larger tires provide...when the increase in tire size is proportional to what we are talking about here.
Enjoy!
09-05-2008, 05:29 AM
#7
JK Jedi
Thread Starter
285/75/16's are just 33's.
32's are a stock size...you you are barely off the stock spec anyway.
IE: the 285's will be 3% over stock.
I'd go to a 305/70/16...about the same 33" diameter, but better flotation and braking, better lateral acceleration, and better rock, dirt, mud and sand traction.
The 285's MIGHT need spacers...the 305's WOULD need spacers...
...But the spacers widen your stance, add cornering and off camber stability, etc.
....So that's a good thing.
32's are a stock size...you you are barely off the stock spec anyway.
IE: the 285's will be 3% over stock.
I'd go to a 305/70/16...about the same 33" diameter, but better flotation and braking, better lateral acceleration, and better rock, dirt, mud and sand traction.
The 285's MIGHT need spacers...the 305's WOULD need spacers...
...But the spacers widen your stance, add cornering and off camber stability, etc.
....So that's a good thing.
"MY" stock size is 245 75 16, which is a 30.5" diameter. I don't know where you came up with 32", unless you used that because Rubicons come with 32s. Rubis DON'T come with 3.73s like mine has, so that's not a good comparison. A 2.5" jump in tire diameter is pretty big. That's what we're talking about from a 245 to a 285. As for being unhappy with the stock performance, for "ME", nothing could be further from the truth......BUT I don't really wanna sacrifice much, you know? There ain't much TO sacrifice. LOL All in all, it's beginning to sound like 265s are my best bet.
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09-05-2008, 06:08 AM
#8
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my '08 X with the 24s package came with 255/75r17s. basically 32" tire. so my thinking was 285s would be perfect.... wrong. with the 3.73s it is fine a lower speeds. but on the HWY it downshifts at the hint of an incline or good headwind. I really didnt think this was going to happen since many of my friends jeeps have 4.10s and 33s and dont do that 
i'm going 4.88s so it wont be any issue much longer
i'm going 4.88s so it wont be any issue much longer