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GC Pentastar 8 speed drive similar to JLU Pentastar?

whatroads

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I travel, for work, nearly every week. This implies I get to rent a lot of cars. Last week I had a new Grand Cherokee Limited with the Pentastar 3.6 w/ 8 speed transmission. I only post this to discuss possible drive similarities with the, yet to be released JL Unlimited.

The GC will weigh around 1-200 pounds more than the JKU. Weight should not be much a factor. The Grand Cherokee was an AWD model. However, these post more power to the rear wheels than the front. I've had many past Jeeps. My wife currently drives a 2012 2dr Pentastar w/ the manual transmission. My current vehicle is a 2011 RAM 1500 QC 4x4 Hemi w/ 3.92 gear. So, I know what power feels like. Past Jeeps include CJ7, YJ, Cherokee 4.0 w/ Manual tranny, A couple GC's and a 2008 JKU

I found the GC w/ the updated Pentastar 8 speed tranny and very good combination. It never really felt wanting for power. I was in the midwest and no where near the mountains. I did disable the auto-stop-start. Off the line was very good. I'm sure it's much faster than my wife's 2012 Pentastar manual tranny. On ramp to highway, start of about 30 mph, easily hit 65 mph by end of entrance ramp with engine still accelerating. I found the 8 speed automatic shifts to be very smooth. Most of the time I did not even know they were happening.

I know everyone is psyched about the diesel and turbo 4 cyl options. Seat of the pants test lends me to believe the Pentastar w/ 8 speed auto will be an excellent engine, for both on and off road, in the new JLU

Auto stop start: Most of the time I barely noticed it. Mostly when pulling up to stop lights and trying to experience the systems effect. When I get a JLU i will likely hit the disable button every tie I start the Jeep. That is, Until I mount a switch to permanently turn it off. One thing I did notice about the auto stop start: When approaching a light, or stop, with relatively heavy brake, you felt the drive train kick in the back end. Kind of like it was unloading. When I turned the auto stop start off the effect went away. For example: 45 mph - 0 due to a stop light sudden change. Or, I simply like to accelerate\decelerate fast
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SMYYOB

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I agree the 8 speed with Pentastar will be a great combo. As far as the 8 speed shifting goes. It doesn't have to follow the normal shift pattern. So if you are jamming on it and it is going 60 in 3rd or 4th gear, and let off, it can shift to 8th without going through the progression of the other gears. It's a fantastic transmission and the only hiccups that may come initially on release should be able to be fixed with a computer upgrade as they do with current models with this transmission. It should be fantastic off road as well be cause the lower gears are where all of the power is. It isn't till 6-8 where it gets moving along at highway speeds. Very exciting indeed.
 

BillyHW

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Speaking of the upgraded Pentastar, does the EGR (exhaust gas recirculation) reduce engine life or let the engine get gunked up with soot/sludge? Is it something I should be worried about?

The new JL 8-speed tranny should be the same as the GC. Everything I hear about it is that it's great.
 

SMYYOB

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I can't imagine that there would be anything special about the EGR. This tech has been out for so long that I can only assume that it's not going to be something that is an issue more than anything else.
 

Bearded_Dragon

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Speaking of the upgraded Pentastar, does the EGR (exhaust gas recirculation) reduce engine life or let the engine get gunked up with soot/sludge? Is it something I should be worried about?

The new JL 8-speed tranny should be the same as the GC. Everything I hear about it is that it's great.
EGR has been on engines for ages. Chances are whatever vehicle you're currently driving has EGR.
 

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DanW

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Speaking of the upgraded Pentastar, does the EGR (exhaust gas recirculation) reduce engine life or let the engine get gunked up with soot/sludge? Is it something I should be worried about?

The new JL 8-speed tranny should be the same as the GC. Everything I hear about it is that it's great.
All they did was cool the exhaust gas being recirculated. That helps power, but doesn't do much else different than EGR valves have always done. I woudn't worry one tiny bit about it.
 

Armycop

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At work I drive a Pentastar 3.6 Durango with the 8 spd and it's not bad. The GC and Durango are a little more aerodynamic but heavier so the mileage should balance out. Its not a hot rod but it's a smooth daily driver. Should average out around low 20s MPG real world. It's rated 19/26 for 2wd probably one MPG less with 4wd.
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