So I have been selling injectors for a little while. I have ask for feedback from the buyers on how they felt the rig has gained performance. I also always ask what specs of the rigs they were putting them in. The point of this thread is to show others what to possibly expect from the upgrade based on the type of rig they have. I truly believe now after talking with people I have sold them to as well as people that I personally know that has done it. I feel confident saying that there is a correlation to results based on the rigs tire size vs gear ratios. This is why there is such a disagreement on the results of the upgrade.

I am going to cover the main aspects of where the gain should be and explain on why. Then I will add the actual data that I have gotten back from people. Categories that This thread will cover for now.

Throttle Response:
Smooth Idle:
Holds Highway Speeds:
MPG's:


Throttle Response- To notice the amount of gain in throttle response the tire size:gear ratio would need to be a good match. The worse the ratio is to each other decreases the possibility of feeling the throttle response. (

Smooth Idle: Just about every rig should notice a night and day gain hear. Ratio:Tire size would obviously not affect this one but for others that wonder if it will help I am adding to the thread

Holds Highway Speeds: Gear ratios matter again here. for people with good ratio:tires size combos they dont really have an issue with highway speed being held anyway. So if it holds the speed better for the big tire high ratios then its and obvious gain. If your jeep holds the speeds fine stock you cant really get a gain from this.

MPG: Directly linked to Holding the highway speeds. People that do not notice the MPG gain have a good ratio. People that notice the the MPG gain are getting better mpgs because they are holding highway speeds better. avg gain was 2-3mpgs better for those that did gain.

I have gotten just about identical responses on both 703's and 784's

These are the averages of the responses I have gotten:

Small: Ratio Stock Vs. up to 31's
Amount of reviews in this category: 6
Scale of (1 to 10) 1=No difference 10=Night and Day
Throttle Response: 8
Idle Smooth:10
Holds highway speeds better:1
Better MPG: 2
4-Low Throttle response:9
Worth doing?: 10

Big: Ratio Stock Vs 32's-34's
Amount of reviews in this category: 3
Scale of (1 to 10) 1=No difference 10=Night and Day
Throttle Response: 6
Idle Smooth:10
Holds highway speeds better:4
Better MPG 3mpg's or more =10: 5
4-Low Throttle response:8
Worth doing?: 10

Big and Strong: 3:73+ Vs 32's-34's
Amount of reviews in this category: 2
Scale of (1 to 10) 1=No difference 10=Night and Day
Throttle Response: 8
Idle Smooth:9.5
Holds highway speeds better:1.5
Better MPG 3mpg's or more =10: 1.5
4-Low Throttle response:6
Worth doing?: 5.5

Huge: Ratio 3:55's-3:73's Vs 35+ tires
Amount of reviews in this category: 4
Scale of (1 to 10) 1=No difference 10=Night and Day
Throttle Response: 2
Idle Smooth: 9
Holds highway speeds better:8
Better MPG 3mpg's or more =10: 7
4-Low Throttle response:6
Worth doing?: 8

Huge and Strong: Ratio 3:73+ Vs 35+ tires
Amount of reviews in this category: 0
Scale of (1 to 10) 1=No difference 10=Night and Day
Throttle Response:
Idle Smooth:
Holds highway speeds better:
Better MPG 3mpg's or more =10:
4-Low Throttle response:
Worth doing?:


If you would like to add your personal experince just include the following and keep it to these categories alone please. I will then edit the first post and add yours to the count in the correct category. If you have a different combo I will add it to the list.

Year:
Model:
Trans (Auto or Manual):
Tire size:
Gear ratio:

Scale of (1 to 10) 1=No difference 10=Night and Day
Throttle Response:
Idle Smooth:
Holds highway speeds better:
Better MPG:
4-Low Throttle response:
Worth doing?:

 

Year: 96
Model: Sport
Trans (Auto or Manual): Auto
Tire size: 33
Gear ratio: 4.56

Scale of (1 to 10) 1=No difference 10=Night and Day
Throttle Response: 7
Idle Smooth: 10
Holds highway speeds better: 1
Better MPG: 1
4-Low Throttle response: 5
Worth doing?: 3

(I'd only do it if I had 200k+ miles and original injectors. Otherwise it's a waste if you ask me)

 

Added yours.

I get what your saying on that. It wont be long before every XJ has 200K+ on them though. lol

 

Good thing the new Cherokee will be out by then

 

I disagree. Mine only has 120k on it and I noticed a difference, it's not a big different but it's not like it takes alot of time or anything. It's like a ten minute install.

 

Year: 99
Model: sport, 4.0, 231
Trans (Auto or Manual): Auto
Tire size: Stock (27"?)
Gear ratio: 3.55s

Scale of (1 to 10) 1=No difference 10=Night and Day
Throttle Response: 6
Idle Smooth: 7
Holds highway speeds better: 5
Better MPG: 8
4-Low Throttle response: 5, though haven't thought about that too much, guess I'm nuetral.
Worth doing?: 8, depends on price you pay, condition of current injectors. Mine were fairly old, and I didn't pay a whole lot for my injectors.



Year: 91
Model: Laredo, 4.0 242 (at the time)
Trans (Auto or Manual): Auto
Tire size: 31x10.50
Gear ratio: 3.73s

Scale of (1 to 10) 1=No difference 10=Night and Day
Throttle Response: 10
Idle Smooth: 8
Holds highway speeds better: 6
Better MPG: 3
4-Low Throttle response: 5, I'm kinda nuetral, can't really say I noticed anything.
Worth doing?: 10, high milage on stock injectors, one or more possibly clogged a little. New ones would've cost more than what I paid for 703s.