Optimum Gears?

[CarbonSteel]

Not intending to be a smart***....Do you think you aren't in the minority because you have seen multiple people on here and on other forums discuss it? There have been over 400k JL's sold and probably 90% are automatics. I've watched God knows how many youtubes + read hundreds of articles and the JL's automatic is always praised and viewed as a gamechanger. JL sales are WAY ahead of the JK after it was launched and it has set multiple sales records. Unless sales take a dive, I'd bet the farm FCA isnt going to do anything to the gearing of the automatic.

P.S...I drive a 6 speed....so no automatic bias here.

My experience cannot be unique and thus the reason I do not see myself in the minority. I would find it difficult to believe that my Rubicon is one of the few of the hundreds of thousands made that does this.

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[beaups]

My experience cannot be unique and thus the reason I do not see myself in the minority. I would find it difficult to believe that my Rubicon is one of the few of the hundreds of thousands made that does this.

I don't think anybody is debating your rig does this, I think the argument is that it's expected and normal.

 

[jessedacri]

This is absolutely normal, you are driving a vehicle with the aerodynamics of a billboard. The wind has a lot more influence on a Wrangler rather than a Prius or something. When my JLR was stock I easily saw the advertised mileage performance and rarely noticed or cared whether it was in 7 or 8. I didn't notice much if any change moving to 35s either - it might see 8 less often but absolutely no desire to regear at this stage. There's more than enough ratio in the auto trans.

If you're more sensitive about the nuances in gearing, go ahead and regear and see how it does. Ultimately it's your rig and the best part about these vehicles is the ease of making them your own regardless of if it's a popular setup or not. There's plenty of people dailying rigs on 37s with stock 4.10s and there's plenty of people running 4.88s on 35s. Different strokes.

 

[CarbonSteel]

This is absolutely normal, you are driving a vehicle with the aerodynamics of a billboard. The wind has a lot more influence on a Wrangler rather than a Prius or something.

There has to be more to it than just aerodynamics--all light trucks have similar aerodynamics and when pulling a trailer the coefficient is far worse than any Wrangler. None of my trucks did this, now perhaps they had enough HP/Torque that they could compensate and so it was a non-issue. With that said, driving unloaded at 70MPH into a headwind should not impact the vehicle that much.

 

[ChattVol]

My experience cannot be unique and thus the reason I do not see myself in the minority. I would find it difficult to believe that my Rubicon is one of the few of the hundreds of thousands made that does this.

I'm not disputing your experience at all...I'm saying you're in the minority bc you care about this enough to continually voice your disproval. The JL's automatic platform is well liked by the vast majority and record sales numbers support it.

 

[CarbonSteel]

I'm not disputing your experience at all...I'm saying you're in the minority bc you care about this enough to continually voice your disproval. The JL's automatic platform is well liked by the vast majority and sales numbers support it.

Hmmm...one thread is hardly "continually voice your disproval", I merely related my experience and am asking:

1. if it would have made more sense to gear the Rubicon with 4.56 from the factory as a way to minimize or eliminate this condition.
2. Is 4.56 the optimum ratio for tires that are 33-34" tall?
3. Is 4.88 the optimum ratio for tires that are 35-36" tall?

 

[Chocolate Thunder]

I’m not an expert by far but I’ll regear to 4.88 when I move to 37s. If I were for certain staying with 35s I’d probably spend the money to regear to 4.56 to improve fuel economy and even though the experts would advise that it’s a waste.

The 8 speed transmission is great. The rear end gearing is what’s not optimal.

 

[beaups]

I’d probably spend the money to regear to 4.56 to improve fuel economy

uh, what?

 

[4xFUN]

I have a Rubi 2-door and switched from the OEM 33" KO2's to 35" KO2's the day after I took delivery...I really did not notice much difference just driving around town but of course I had also not really gotten used to my new JLR either. However after installing a lift (2.25") and lots of HD / heavy (Steer Smarts) steering linkage (drag link, track bar & Rubi-length tie rod) plus the weight of various skid plates, I did notice a drop off in performance...
I honestly feel the OEM 4.10 gears are very well matched with the gearing in the 8 speed auto for 33" tires, with my 35" tires the optimum ratio (to maintain OEM ratios) would be 4.56. I am not thrilled about the prospect of re-gearing and really do not think the relatively minor drop-off in performance warrants a re-gear...That said, I am optimistic the Mopar CAI I recently installed, the soon to be released Borla Touring Climber Cat-back (for the 2-door JL) plus a Livernois 91 octane tune will restore or even enhance lost performance!

 

[GerJL]

Good thing you don't drive a KL Cherokee. It has the elusive 9th gear that is never seen. Well once when I was doing over 100 I know it hit 9th. It has something like 4 ODs and even 8th is rarely seen unless I am doing 80 or more.

 

[ChattVol]

Hmmm...one thread is hardly "continually voice your disproval", I merely related my experience and am asking:

1. if it would have made more sense to gear the Rubicon with 4.56 from the factory as a way to minimize or eliminate this condition.
2. Is 4.56 the optimum ratio for tires that are 33-34" tall?
3. Is 4.88 the optimum ratio for tires that are 35-36" tall?

You should call Jeep's MFG facility in Toledo and ask for their engineering dept and ask why they selected 4.10 gearing with 33s. I imagine they tested it extensively and felt 4.10 gearing with 33s was a nice combo for the vast majority of potential buyers. Record sales and countless positive reviews support it has been a huge success. If you are one of the few who cant live with the stock setup, regear or sell it. I'm out on this thread...no response needed.

 

[Revolution_322]

Well, on a 5,000 mile road trip, that would get as old as the 7th and 8th gear changeups. Just a little nuts to have a headwind effect a vehicle to the point of downshifting. I have owned many trucks in my time (which are also not very aerodynamic and they never downshifted (or would not upshift) in response to a headwind.

They probably also had 4 -5-6 speed transmissions too. Sounds like we got another first time jeep owner here

 

[oldcjguy]

All companies are penalized for poor fuel economy, it is not unique to FCA. However, this is the first vehicle that I have owned that downshifts as frequently as this one does. I am in the minority of not liking it?
<shrug>

I think you are remembering older vehicles more fondly. Have you driven the newer GM or Fords with the 10sp auto? Those things are constantly hunting. Personally, I think the fca calibrators did a much better job on the zf. That being said I think some form of hunting is the new normal.

Our TCMs be like, "so many choices"

 

[Revolution_322]

Yea my WJ holds 4th like a champ up inclines lol
But my jl can smoke a camrey Off the line

 

[ChattVol]

Yea my WJ holds 4th like a champ up inclines lol
But my jl can smoke a camrey Off the line

Was it a v6 camry by chance?

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