New To Jeep, Looking for some Sugestions.
Thread Starter
JK Newbie
Joined: Nov 2010
Posts: 27
Likes: 0
From: Red Deer, Alberta
New To Jeep, Looking for some Sugestions.
Hello Everyone. I am very new to Jeep. I am in amongst my first Jeep purchase. I have narrowed it down to 2. I have driven both of them. One is a 2008 Rescue Green Rubicon unlimited with a 6 speed trans. The other is a 2008 Black Rubicon unlimited with a Auto trans. I am a big fan of the green myself but not sure about the 6 speed. (I like driving standards) I just don't know how it will hold up against the Auto? What is a better Trans in these Rubicons? I am also wondering about lifts and tires. I have decided on a 4" Lift and 35" Tires. Are the 4:10 gears good enough to run this Lift/Tire setup? I do about 80% town and 20% Hi way. Minimal off road, just going in the bush to do some camping and quading. Any recommendations on Transmission, 4" Lift brands, 17" or 18" Wheel width and offsets.
Thank you in advance Derek.
Thank you in advance Derek.
JK Freak
Joined: Oct 2009
Posts: 787
Likes: 0
From: Lake Villa, IL
If you are planning an Unlimited with 35's and 4.10's and dont plan on regearing go with the 6 spd. You will be much happier in the end.
Here is a good place to start on the general topics.
https://www.jk-forum.com/forums/show...276#post211276
I have 2009 6spd and love it.
Here is a good place to start on the general topics.
https://www.jk-forum.com/forums/show...276#post211276
I have 2009 6spd and love it.
JK Super Freak
Joined: Apr 2010
Posts: 1,271
Likes: 2
From: New Brunswick
If you buy the auto you WILL be regearing with 35's. With the 6 speed you won't need to as it is tolerable.
Terraflex has an amazing christmas special on, check out their post in the sponsor section.
Terraflex has an amazing christmas special on, check out their post in the sponsor section.
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
This is a good Auto vs Manual post from another thread, the last two sentences sum it up nicely. It may help with your decision.
https://www.jk-forum.com/forums/show...itude%29/page3
(my opinion. You like manuals, sounds like you don't want to regear, don't get an auto...)
Originally Posted by Planman
Here is an explanation as to why Auto vs. Manual makes a huge difference:
First, here is the rear wheel horsepower and torque curve information for a JK:
< chart goes here - thread is linked below >
Next, assuming a 35" tire measures 34" when mounted to a wheel, set at an appropriate psi, and run on a JK, 70 mph produces the following rpm levels with 5.13 gears:
Automatic: 2450 rpm
6 Speed: 2982 rpm
The corresponding rear wheel horsepower at 70 mph with a stock tune is:
Automatic: 75 rear wheel horsepower
6 speed: 93 rear wheel horsepower
Even with 5.38s and 2569 rpm, the automatic produces about 80 rear wheel horsepower at 70 mph. However, add a Superchips 91 octane tune to the 5.38s and the automatic rear wheel horsepower at 70 mph is about equal to the 6 speed 5.13 gear rear wheel horsepower at the same speed--not to mention increasing rear wheel torque from 160 to 185.
75 rear wheel horsepower with an automatic and 5.13 gears is not enough to hold speed on highway grades at elevation. Make it a 4 door instead of a 2 door, and run heavier tires, armor, and gear, and you are in for a miserable experience.
An automatic owner who runs 5.38s and a Superchips 91 octane tune increases from 75 to about 93 rear wheel horsepower and from 160 to 185 torque. The combination of the 5.38s and the Suprchips at least give hime some some chance of not overheating his transmission and killing his fuel economy from the constant downshifting.
For those of us with 6 speeds, we don't have as much to complain about. With 5.13s and 35s (34" actual height) and a Superchips 91 octane tune, we run about 108 rear wheel horsepower and more than 185 torque at 70 mph. This gives us enough power to drive most any freeway grade--even at high elevations--in 6th gear with the cruise control on.
This is why the automatic vs. 6 speed is so huge, and why the automatic 42RLE transmission that Chrysler chose to put in the JK is pathetic.
This is also why we constantly read threads from guys complaining about the lack of power in the JK engine--nearly all of them have automatics.
In fact, a 6 speed owner with 5.13s would need to run 40" tires (39" actual mounted height) to turn the same rpm with the same horsepower as an automatic with 5.13s and 35s.
Brent, imagine the change in performance if you went from 35s to 40s with the same gearing.
Here is an explanation as to why Auto vs. Manual makes a huge difference:
First, here is the rear wheel horsepower and torque curve information for a JK:
< chart goes here - thread is linked below >
Next, assuming a 35" tire measures 34" when mounted to a wheel, set at an appropriate psi, and run on a JK, 70 mph produces the following rpm levels with 5.13 gears:
Automatic: 2450 rpm
6 Speed: 2982 rpm
The corresponding rear wheel horsepower at 70 mph with a stock tune is:
Automatic: 75 rear wheel horsepower
6 speed: 93 rear wheel horsepower
Even with 5.38s and 2569 rpm, the automatic produces about 80 rear wheel horsepower at 70 mph. However, add a Superchips 91 octane tune to the 5.38s and the automatic rear wheel horsepower at 70 mph is about equal to the 6 speed 5.13 gear rear wheel horsepower at the same speed--not to mention increasing rear wheel torque from 160 to 185.
75 rear wheel horsepower with an automatic and 5.13 gears is not enough to hold speed on highway grades at elevation. Make it a 4 door instead of a 2 door, and run heavier tires, armor, and gear, and you are in for a miserable experience.
An automatic owner who runs 5.38s and a Superchips 91 octane tune increases from 75 to about 93 rear wheel horsepower and from 160 to 185 torque. The combination of the 5.38s and the Suprchips at least give hime some some chance of not overheating his transmission and killing his fuel economy from the constant downshifting.
For those of us with 6 speeds, we don't have as much to complain about. With 5.13s and 35s (34" actual height) and a Superchips 91 octane tune, we run about 108 rear wheel horsepower and more than 185 torque at 70 mph. This gives us enough power to drive most any freeway grade--even at high elevations--in 6th gear with the cruise control on.
This is why the automatic vs. 6 speed is so huge, and why the automatic 42RLE transmission that Chrysler chose to put in the JK is pathetic.
This is also why we constantly read threads from guys complaining about the lack of power in the JK engine--nearly all of them have automatics.
In fact, a 6 speed owner with 5.13s would need to run 40" tires (39" actual mounted height) to turn the same rpm with the same horsepower as an automatic with 5.13s and 35s.
Brent, imagine the change in performance if you went from 35s to 40s with the same gearing.
(my opinion. You like manuals, sounds like you don't want to regear, don't get an auto...)
Last edited by nthinuf; Nov 30, 2010 at 01:05 PM.
JK Enthusiast
Joined: Jun 2010
Posts: 128
Likes: 0
From: Horizon City, tx
standard is your way to go hands down, the only reason my 2 door is an auto is because im teaching my little cousin how to drive. i really do advise the standard ull have more torque at lower rpms which will make your wheeling all the more better.
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Thread Starter
JK Newbie
Joined: Nov 2010
Posts: 27
Likes: 0
From: Red Deer, Alberta
Thanks for the input guys, I wasn't sure of how strong the 6 speed would be but it sounds like not to many people believe in the Auto. Any sugestions on offsets for the wheels?
JK Jedi Master
Joined: Jan 2008
Posts: 11,463
Likes: 165
From: Austin <--> Colorado Springs
Open the FAQ's stickied to the top of this modified area for more info. Most lift mfg's recommend a minimum of 4.50 backspace for 35x12.50's. (stock BS is 6.25)
