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Discussion Starter #1
I'm curious, those with automatics, how many of you use your "manual" gear shift to help slow down your Jeep and how often.

I have found myself using the engine as a brake more often around town. This past weekend I used it a lot in the mountains.

Also, is this bad for the engine? Wouldn't think so but I'm no mechanic.
 

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I'm not a mechanic either, but just doing this around down...Wouldn't that put more stress and wear on the engine and the tranny, rather than some cheaper brake components?
 

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If you ever go to a performance driving school you will learn that brakes are the strongest, most effective and cheapest means to slow a vehicle.
Most people see in car video of race cars gearing down for corners, what they do not realize is that the braking is what is slowing the car down, and all they are doing with gearing is ensuring they have the revs up to balance the car through the corner and power out on exit.
Only people that use the engine to "brake" are big diesels with properly designed jake-brakes...
 

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I drive one with a six speed manual, it slows down quicker in neutral going down hill than any other vehicle I've ever driven!

And yup.... Once my dad asked me why I don't down shift to slow down. I told him because brakes are cheaper and easier to replace than a clutch. His reply.... hmmm... never thought of it that way.
 

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I'm not a mechanic either, but just doing this around down...Wouldn't that put more stress and wear on the engine and the tranny, rather than some cheaper brake components?
Manually shifting automatics are the new rage in vehicles these days. Probably keeps AAMCO-type companies purring. Manually downshifting can be useful in some situations but I'd rather not use it "often around town" unless maybe if it was a rental.
 

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Being from the race car world when I was younger.. one is taught to down shift upon entering a curve or sharp turn. If you've ever watched road racing and noticed flames coming from the side or tail pipes.. this is cause by down shifting.

We test drove the wrangler Fri and noticed the automatic has the +/- on the drive setting.. This wasn't intended to be used as for down shifting like a race car. More over it's main use is to when you towing up hill and you force the transmission to remain in a lower gear for that up hill climb.
 

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Wow, I have found that the Jeep slows down crazy fast on it's own compared to every other vehicle that I have ever driven.

This thing coasts like a brick sliding down a slide covered in sandpaper.
Interesting. I felt the opposite about my JK when I took delivery. Brake performance seemed unimpressive for such a light vehicle. All my other cars/trucks seemed much more responsive. It's adequate...but nothing more.
 

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You don't engine brake in the mountains to save money. It's more so your brakes don't get overheated and fail on you when you need them.

The few places where they measure your brake temperature, you will also get an involuntary break if you have been using your brakes instead of your engine.
 

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You should never use the transmission to help slow down a vehicle. Even on the track we are using the brakes to slow down, we are also shifting gears but that is to ensure that we are in the proper gear and rpm to pick up the throttle when we come off the brakes.

The only exception to this is when you are towing and going down hill. Use the tranny to control your speed not the brakes. The general rule of thumb has always been the gear you go up the hill is the gear you should use to go down.
 

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Interesting. I felt the opposite about my JK when I took delivery. Brake performance seemed unimpressive for such a light vehicle. All my other cars/trucks seemed much more responsive. It's adequate...but nothing more.
I believe he means when coasting the JK slows down faster than most other vehicles, not talking about braking performance. I find the same is true, if I just let off the gas and let it coast I'll slow down quicker than my previous vehicles but if I'm on the brakes they are definitely unimpressive.
 

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Down shifting an automatic is no harder on the transmission then when it up shifts when accelerating. The feature is put into truck transmissions --like the jeep -- to help with engine braking so the engine does not "race" when off road and towing. Additionally it helps with cooling of the transmission in those situations by pumping more fluid through the transmission and cooler. If this feature was harmful for the transmission or engine do you think it would be designed that way.
 

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Discussion Starter #15
I believe he means when coasting the JK slows down faster than most other vehicles, not talking about braking performance. I find the same is true, if I just let off the gas and let it coast I'll slow down quicker than my previous vehicles but if I'm on the brakes they are definitely unimpressive.
Yep! Exactly this!

So I suppose bigger brakes are the answer because the ones that come with it are certainly unimpressive!
 

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Discussion Starter #16
Down shifting an automatic is no harder on the transmission then when it up shifts when accelerating. The feature is put into truck transmissions --like the jeep -- to help with engine braking so the engine does not "race" when off road and towing. Additionally it helps with cooling of the transmission in those situations by pumping more fluid through the transmission and cooler. If this feature was harmful for the transmission or engine do you think it would be designed that way.
So it seems we have 2 different schools of thought going on in this thread. This is what I thought but others seem to say no way.

In all my other vehicles 2 and 4 wheel, I have always down shifted, the by-product has always been that it assists with slowing the vehicle down, but allows me to be in the correct gear to accelerate if needed and gives the feeling of better stability if any maneuvering is needed.

To clarify my op some, to me, this seems almost necessary in the Jeep because of how lack luster the breaking feels.
 

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I was pleasantly surprised to find this feature existed in the Jeep automatic. I use it to keep the Jeep from going too fast downhill in snow and slippery conditions, when you don't want to have to jam on the brakes.

I also use it when the Jeep decides to be sluggish changing gears up a hill and I need to get moving faster.

I am of the opinion that if the system couldn't handle the up and down shifts, they wouldn't have built it in...
 

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I'm with mmicjk.as long as you're not over going into the red zone on the rpm,s its ok.i don't think they would have put in the feature.youre either gonna hit the rev limiter as you would in the new challengers or the computer will up shift for you.a lot of the new 18 wheelers run tap shift automatics and they let you do it..ps the steepest hill around on the hi way my mustang coasting id be going 90mph,,,the jeep coasting same hill would slow down
 

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I was pleasantly surprised to find this feature existed in the Jeep automatic. I use it to keep the Jeep from going too fast downhill in snow and slippery conditions, when you don't want to have to jam on the brakes.

I also use it when the Jeep decides to be sluggish changing gears up a hill and I need to get moving faster.

I am of the opinion that if the system couldn't handle the up and down shifts, they wouldn't have built it in...
This is the way it should be used, not as a means to slow the vehicle, aka, in lieu of brakes.
For all those who want to use it to control speed on long downhills... trucks have this feature to utilize when loaded to the hilt/towing... it is there as an aide to keep from over heating the brakes and having them fail, not as a primary means to slow the vehicle... especially not in everyday driving around town or with a light load simply going downhill out on the highway.
You are not meant to ride the brake all the way down a mountain either... let the vehicle build some speed, brake to reign it in, let the brakes cool, vehicle builds speed, brake... repeat.
If the vehicle is fully loaded and/or towing, then yes, by all means engine braking will be required as an assist (not primary), but that is not what OP asked.

And again, race cars use the brakes to slow, and downshift to be in the right gear for the speed they will need to be exiting... they are manual trans vehicles, and need to shift, no, they are not automatics.
 

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About the only time(s) that I will use the downshift feature is when I need to stop quickly or unexpectedly-- I will apply the brakes forcefully while also doing a 'bump shift' or two. I also have been known to use it to 'force' a downshift when going up a hill, especially when I don't want to increase my throttle significantly to achieve similar results.

Exco
 
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