33" BFG'S 2009 auto are 4.88's to low?
#12
JK Newbie
Thread Starter
Join Date: Sep 2009
Location: Redding Calif.
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
My jeep stock came with LT 25575R17 they measure 32.1" per BFG web site .It came stock with 4:10 gears.
I currently have LT28570R17 they measure 32.8" at 60 mph ithe LT 255 in hi gear my rpm with O/D off is 2,575
At 60 mph in hii gear O/D off my rpm with the LT285 my rpm is 2,520 . It does not seem like much diff. In rpm
But you can really feel it in O/D. I have been looking through lots of treads but most every body is running
35's. I was just looking for someone with the same set up is all. I work A lot and just don't have the time to search
The treads all night..
I am thinking I will go with the 4:88's
I currently have LT28570R17 they measure 32.8" at 60 mph ithe LT 255 in hi gear my rpm with O/D off is 2,575
At 60 mph in hii gear O/D off my rpm with the LT285 my rpm is 2,520 . It does not seem like much diff. In rpm
But you can really feel it in O/D. I have been looking through lots of treads but most every body is running
35's. I was just looking for someone with the same set up is all. I work A lot and just don't have the time to search
The treads all night..
I am thinking I will go with the 4:88's
#13
JK Jedi Master
Join Date: Jan 2008
Location: Austin <--> Colorado Springs
Posts: 11,463
Likes: 0
Received 162 Likes
on
154 Posts
LT 25575R17 they measure 32.1". LT28570R17 they measure 32.8".
Regearing is expensive - why not just run with OD Off until you can find the time to do some research? Lots of people do this after buying taller tires until they get around to gears.
And for what it's worth, I ran 295/75/16's (33.27" mfg spec - 32" measured height under jeep) with 5.13's for a while before moving up to 35's. If you want to see what rpm that corresponds to, you can click the link and plug the numbers into the chart...
#14
JK Newbie
Thread Starter
Join Date: Sep 2009
Location: Redding Calif.
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
NTHINUF thanks for all your advice you have been a real big help!
I though this forum was to get advice not get criticized by other
Members on this forum?
I though this forum was to get advice not get criticized by other
Members on this forum?
#15
You will find lots of members telling you to gear very high on this forum and that is fine if you really dont DD your jeep but in my opinion 4.88 seems crazy high for 33s. I have 35s and my stock 3.21 gears and really cant complain too much about road power and do just fine off road. Most will tell you i am an asshole for running this ratio. But being my DD, ill accept the power loss and happily drive around at 18.5 mpgs. I will be regearing to 4.10s to accommodate for my 35s once i have some spare cash. Good luck on your decision. (Btw i have a 2dr 3.6 auto)
#16
JK Jedi Master
Join Date: Jan 2008
Location: Austin <--> Colorado Springs
Posts: 11,463
Likes: 0
Received 162 Likes
on
154 Posts
You have a different engine and a different transmission. Your gearing comments/recommendations will only confuse someone with a pre-2012 auto.
If you look at the charts mentioned above, you can easily see the rpm difference between the two engine/transmission combos.
If you look at the charts mentioned above, you can easily see the rpm difference between the two engine/transmission combos.
#17
JK Enthusiast
Join Date: Apr 2008
Location: rc,sd, us
Posts: 173
Likes: 0
Received 0 Likes
on
0 Posts
I see this over and over on this forum. It's causing a lot of confusion for the misinformed.