# 05 Frontier - Downshifting while downhill



## Beckman (Oct 3, 2005)

Hello all,

Since I've had the new Frontier (auto crew cab), I've noticed that when I am going down a very long steep hill and press the brake, the truck downshifts and of course the rpm's go up. 

It's almost as if there is some sort of sensor that determines if the hill is steep enough, then downshifts when there is braking. It doesn't do this on moderate hills.

Has anyone else experienced this? It's not a big deal - just want to know if it's normal or something I should be concerned about.

Thanks, Beck


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## bender031 (Aug 30, 2005)

Yeah apparently it is normal my 05 pathfinder does the same thing and i questioned the service manager at the dealership. If you are on a certain down grade, and hit the brakes, it will shift to third gear to engine brake and help reduce speed. Once you are used to it, and know that it is normal, it ends up being a nice feature, and if you practice you can hit the brakes at the right time and have it kick in on demand...

if you search my username i posted about this a while back...i had first noticed it because i was manually hitting the od off button and the rpms were actually going down (because the car had been downshifting to 3rd on its own.)


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## Beckman (Oct 3, 2005)

bender031 said:


> Yeah apparently it is normal my 05 pathfinder does the same thing and i questioned the service manager at the dealership. If you are on a certain down grade, and hit the brakes, it will shift to third gear to engine brake and help reduce speed. Once you are used to it, and know that it is normal, it ends up being a nice feature, and if you practice you can hit the brakes at the right time and have it kick in on demand...
> 
> if you search my username i posted about this a while back...i had first noticed it because i was manually hitting the od off button and the rpms were actually going down (because the car had been downshifting to 3rd on its own.)


Yo....thanks Bender. Good to know it's normal.

Beck


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## jeffro (Jan 6, 2004)

I noticed my truck doing this while going down a steep winding road off a mountain side. Thought something was wrong with the transmission at first as the rpms were going up but the truck was not shifting up like it usually did. After a while I noticed that it was only doing it on the steep parts, and it seems like a nice feature to me.


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## GTIMANiac (Jan 14, 2006)

I drive a 6-speed, but it is comforting to see that they put enough logic into the tranny control module to downshift on steep grades. I just wish other drivers were smart enough to do it! Nothing worse than being behind some clown riding their brakes down grades...


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## d3l0n6 (Feb 10, 2006)

GTIMANiac said:


> I drive a 6-speed, but it is comforting to see that they put enough logic into the tranny control module to downshift on steep grades. I just wish other drivers were smart enough to do it! Nothing worse than being behind some clown riding their brakes down grades...


I guess i'm one of those clowns. In my tacoma i'll depress the clutch or just shift to nuetral on downgrades to keep the rpms low and save gas. I wish my cc nismo 4x4 came with a 6speed manual because it gives you so much more control. When I notice the tranny downshifting i'll pop in in neutral and just coast it out. I guess it just boils down to how much faith you put in your brakes and how often you want to change them while you're trying to squeeze out the best possible mpg. By the way I drive my trucks pretty much exclusivly in the southeast so no huge hills to bother with.


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## GTIMANiac (Jan 14, 2006)

d3l0n6 said:


> I guess i'm one of those clowns. In my tacoma i'll depress the clutch or just shift to nuetral on downgrades to keep the rpms low and save gas. I wish my cc nismo 4x4 came with a 6speed manual because it gives you so much more control. When I notice the tranny downshifting i'll pop in in neutral and just coast it out. I guess it just boils down to how much faith you put in your brakes and how often you want to change them while you're trying to squeeze out the best possible mpg. By the way I drive my trucks pretty much exclusivly in the southeast so no huge hills to bother with.


Engine Braking is much better when going down grades. Also you glaze your pads not just wear them out, you glaze them over reducing their effectiveness and also heating all components up causing brake fade.

When off roading and I am descending grades, I usually engage 4lo and let engine braking idle me down the grade. I have full control without riding the clutch or the brake.

There is a reason major grades have signs that state "Trucks user lower gears". 

Also in some states it specifically states that you should not move with the vehicle in neutral. As again you have given up the control of using the engine for braking and acceleration. Google on “unsafe coasting”.

P'cola aye? I lived in Fort Walton for 13 yrs. I would tend to agree until you get up towards Montgomery way you have very little grade to navigate.


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## fishbreath (Feb 14, 2006)

GTIMANiac said:


> Engine Braking is much better when going down grades. Also you glaze your pads not just wear them out, you glaze them over reducing their effectiveness and also heating all components up causing brake fade.
> 
> When off roading and I am descending grades, I usually engage 4lo and let engine braking idle me down the grade. I have full control without riding the clutch or the brake.
> 
> ...


If your on ice and your rpms go to high you could loose traction. Some times it better to put it in neutral and lightly ride the brakes.


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## CT_Nismo (Dec 25, 2005)

I have a 6 speed in my Nismo and it does not automatically downshift when going down a grade. Warranty issue?

  LOL only joking.

Safety is more important than mpg so in traffic I will use a lower gear to brake in descending a hill. But with no traffic and an open road, I will engage a gear and de-clutch and ride it all the way down the hill. Never too fast though; but preserving the momentum saves in mpg. I re-engage the clutch on the upslope at the speed that is correct for the gearing (double clutching not needed). 

I agree that riding a brake all the way down indicates a neophyte behind the wheel. Stay away.


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## GTIMANiac (Jan 14, 2006)

fishbreath said:


> If your on ice and your rpms go to high you could loose traction. Some times it better to put it in neutral and lightly ride the brakes.



High RPMs do not indicate vehicle speed only engine speed.


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## GTIMANiac (Jan 14, 2006)

CT_Nismo said:


> I have a 6 speed in my Nismo and it does not automatically downshift when going down a grade. Warranty issue?
> 
> LOL only joking.
> 
> ...


RPMS != FuelConsumption
Anyone that has towed a trailer knows that RPMs alone do not equal fuel consumption. Fuel Consumption is more closely related to engine load.

Fact is you do not have full control of your vehicle while coasting, period.


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## d3l0n6 (Feb 10, 2006)

Not to be the devils advocate but in certain situations RPM's do in fact have a direct impact on fuel consumption such as while coasting down Mount Everest at idle or engine braking all the way at redline. What I've gathered from this thread is that using more fuel (not by much though) is the trade-off for increased safety. 

Fishbreath meet me in arkansas out at my parents house after an ice storm. I'll go down their hill in 4lo and you can use the brakes. Then whoever ends up having to be pulled out by the other can buy the beer that night.


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## CT_Nismo (Dec 25, 2005)

GTIMANiac said:


> RPMS != FuelConsumption
> Anyone that has towed a trailer knows that RPMs alone do not equal fuel consumption. Fuel Consumption is more closely related to engine load.
> 
> Fact is you do not have full control of your vehicle while coasting, period.


It is a fact that the least brake intervention one does, the better it is for mpg. Brakes convert the kinetic energy of the truck to heat and dissipate the heat into the air. Hybrids capitalize on this by converting the energy of braking into electrical current and charge the battery. Engine braking does the very same thing; you lose energy that must be made up by burning gas going uphill.


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## inyourface1650 (Oct 6, 2005)

Actually RPMS DO equal fuel consumption. On a long trip, drive a portion of it in 6th gear(on a manual). Stop, fill up, and then keep going, but keep it in 5th gear. I think you will find there will be 1-2 (at least) MPG hit from the extra 1000RPM or so you'll be running at. Now since your going the same speed, and all that, you are using the same amount of power to move the truck....yet, your consumption will go up.
When I first thought about it, I didnt think so either....But there is a REASON that there is a 6th gear..

Towing, I get about 11MPG...so i dont even go there.


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## GTIMANiac (Jan 14, 2006)

inyourface1650 said:


> Actually RPMS DO equal fuel consumption. On a long trip, drive a portion of it in 6th gear(on a manual). Stop, fill up, and then keep going, but keep it in 5th gear. I think you will find there will be 1-2 (at least) MPG hit from the extra 1000RPM or so you'll be running at. Now since your going the same speed, and all that, you are using the same amount of power to move the truck....yet, your consumption will go up.
> When I first thought about it, I didnt think so either....But there is a REASON that there is a 6th gear..
> 
> Towing, I get about 11MPG...so i dont even go there.


We are talking about descending grades not "driving" at high RPMs. I stick to my original statement if you ride your brakes down a hill you are a clown. But someone has to keep insurance companies and Midas in business.


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## inyourface1650 (Oct 6, 2005)

oh yeah, well, in that case. Hell Yeah....I coast where I can, but if it goes overboard on the speed in gear she goes...


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## fishbreath (Feb 14, 2006)

GTIMANiac said:


> High RPMs do not indicate vehicle speed only engine speed.


 Your right, rpms do not indicate vehicle speed. What I said, when going down a snow or ice covered road even if you are going slow in a low gear and the rpms go to high your rear tires can loose traction, on a 2 wd. And yes , with 4 wheel drive going down a hill your weight is transferred to the front wheels and you will not loose traction as easy. My experience come from 30 years of driving a 30,000 lb vehicle and having to take a driving class every 4 years. Sorry if I didn't make myself clear and offended you. Hey what the heck, for kicks and giggles put you truck in 2wd. and my frontier is only 2wd and we can go up or down any mountian here in PA. and if I go off the road and you don't I'll buy you a CASE of beer. I don't need 4wd to drive in the snow. But I could use it to avoid some people with 4wd that think they can go anywhere. :cheers:


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## MrFancypants (Nov 18, 2005)

Yeah I think you misinterpreted fishbreath's comment. When driving on any slick surface you want to keep RPM's as low as possible to maximize traction. If you have the RPM's high the tires are more likely to break loose. This is why you'll often start from a stop in 2nd gear on snow.

In slippery conditions, the best bet is to cut power to all wheels (neutral) and use your brakes. Think of it this way... if the clutch is engaged, the motor is turning the wheels whether you have your foot on the gas or not. This can cause your vehicle to spin out when one powered wheel has traction and the other does not. This is the same course of action when losing control on a dirt road -- shift into neutral (or depress clutch) and remove all engine power from all wheels.

4WD systems are not meant to give you control going downhill. They are meant to give you traction to move the car forward. A lot of people get themselves into trouble thinking that 4WD improves handling on slick surfaces. That is a dangerous mistake to make.


- Greg -


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