Quick question on downshifting...

[mistaare]

Just picked up a GMC 1500 last week, coming from 11 years in a 6spd Tacoma.

Two questions:

1. when in/after the break-in period can I start downshifting to help the brakes, we have some short steep hills here in the north east.
2. does downshifting and coasting use more or less gas when the RPM’s are 3g’s and you are just coasting? 
 

thanks for any input! 

[ct_corey]

Don't bother downshifting. the extra stress on the drivetrain isn't worth getting a few more miles out of your brake pads. 

[Wiggums]

You can do it now. I was already doing that when I got it brand new.

 

The V8 has decent braking power so I don't need to hit my brakes when I'm driving the steep road next to the ranch. And there's always a cop up front.

 

I was told coasting doesn't use gas. And I don't know if the engine braking uses gas, the DIC shows 99 mpg (the maximum) as if I was coasting on neutral.

[Wiggums]

6 minutes ago, ct_corey said:

Don't bother downshifting. the extra stress on the drivetrain isn't worth getting a few more miles out of your brake pads. 

 

A few more miles? I have 3,000 miles and 98% left. I can do about 300,000 miles before needing one. My Ford was at 92% when I traded it in at 44,000 miles. The drivetrain is very solid and it is made to do that.

[ct_corey]

5 minutes ago, Wiggums said:

 

A few more miles? I have 3,000 miles and 98% left. I can do about 300,000 miles before needing one. My Ford was at 92% when I traded it in at 44,000 miles. The drivetrain is very solid and it is made to do that.

Its not made to constantly downshift up into the higher rpms to get the slowing down affect. Higher RPMs put more stress on the engine. that's a fact. 

 

The brake pad sensors are VERY inaccurate and many posters have stated.  My truck says I have 24% left but my pads looks almost brand new. 

 

I promise you wont get 300k out of your truck, let alone the brake pads lol. 

 

 

[KARNUT]

Most vehicles if you use cruise control will downshift to maintain speed going downhill. When running exhaust I would downshift for obvious reasons. Vehicles now have rev matching. It’s pretty cool manually shifting, up or down. Most people don’t bother.


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[Wiggums]

6 minutes ago, ct_corey said:

Its not made to constantly downshift up into the higher rpms to get the slowing down affect. Higher RPMs put more stress on the engine. that's a fact. 

 

The brake pad sensors are VERY inaccurate and many posters have stated.  My truck says I have 24% left but my pads looks almost brand new. 

 

I promise you wont get 300k out of your truck, let alone the brake pads lol. 

 

 

 

When you drive, you're always using the back of the tooth in the gears, not the front. Downshifting, you're engaging the teeth in the opposite direction, might as well put that to use. As for the engine, it's the compression stroke and anybody will recommend that over using the brakes.

I have gone through 14 cars in my entire life and not one have had brakes replaced.

If you think it's great braking instead of downshifting, then you're clearly not worth my time. Good riddance.

[Wiggums]

11 minutes ago, KARNUT said:

Most vehicles if you use cruise control will downshift to maintain speed going downhill. When running exhaust I would downshift for obvious reasons. Vehicles now have rev matching. It’s pretty cool manually shifting, up or down. Most people don’t bother.

 

I tried that with my Ford but it seemed to prefer braking instead. That was annoying, but I know I've rented numerous cars and some were good at downshifting. Haven't really tried that with my current Cheyenne, but it wasn't hilly when I drove to LAX and back, netting 31 mpg on my 5.3 V8 with 4x4.

[ct_corey]

6 minutes ago, Wiggums said:

 

When you drive, you're always using the back of the tooth in the gears, not the front. Downshifting, you're engaging the teeth in the opposite direction, might as well put that to use. As for the engine, it's the compression stroke and anybody will recommend that over using the brakes.

I have gone through 14 cars in my entire life and not one have had brakes replaced.

If you think it's great braking instead of downshifting, then you're clearly not worth my time. Good riddance.

you are wrong but its okay. keep believing in your uninformed logic. 

[ct_corey]

https://www.apautoparts.com/things-never-automatic-transmission/

 

Never use the automatic transmission to slow down

If you were taught to drive with a manual gearbox, you may have learned to downshift the transmission to slow the vehicle down while approaching a stop light or descending a hill. This practice is not acceptable in automatic transmissions because a forced downshift at high-engine RPMs can result in excessive transmission wear, specifically to the clutch friction plates and the transmission bands. When you need to come to a stop or slow down in an automatic vehicle, always apply pressure to the brake and leave the gear selector alone.

[KARNUT]

 
I tried that with my Ford but it seemed to prefer braking instead. That was annoying, but I know I've rented numerous cars and some were good at downshifting. Haven't really tried that with my current Cheyenne, but it wasn't hilly when I drove to LAX and back, netting 31 mpg on my 5.3 V8 with 4x4.

My 14 GMC would rev match, had fun with it.


Sent from my iPhone using Tapatalk

[Wiggums]

7 minutes ago, ct_corey said:

https://www.apautoparts.com/things-never-automatic-transmission/

 

Never use the automatic transmission to slow down

If you were taught to drive with a manual gearbox, you may have learned to downshift the transmission to slow the vehicle down while approaching a stop light or descending a hill. This practice is not acceptable in automatic transmissions because a forced downshift at high-engine RPMs can result in excessive transmission wear, specifically to the clutch friction plates and the transmission bands. When you need to come to a stop or slow down in an automatic vehicle, always apply pressure to the brake and leave the gear selector alone.

 

Oh, God, he said hills, not stop lights. I don't downshift at stop lights! Geez.

[Wiggums]

7 minutes ago, KARNUT said:

My 14 GMC would rev match, had fun with it.

 

I had a similar experience with the Impala I rented. I was impressed at the technical part of it and how it would seem to know what's the best by downshifting and rev matching. Ford and Benz braked instead and I was disappointed.

I haven't really had the opportunity to do that with my current Cheyenne since it's been at the ranch, but it will soon be my daily commuter since gas mileage is so great.

[KARNUT]

https://www.apautoparts.com/things-never-automatic-transmission/
 

Never use the automatic transmission to slow down

If you were taught to drive with a manual gearbox, you may have learned to downshift the transmission to slow the vehicle down while approaching a stop light or descending a hill. This practice is not acceptable in automatic transmissions because a forced downshift at high-engine RPMs can result in excessive transmission wear, specifically to the clutch friction plates and the transmission bands. When you need to come to a stop or slow down in an automatic vehicle, always apply pressure to the brake and leave the gear selector alone.

You don’t have a clue. Most will rev match. I’ve been downshifting for 40 years. I used to have to rev match with two feet. Even with a stick. Now they all pretty much do it. Most vehicles wouldn’t down shift if damaged can happen. If you do anything too much damage can happen. Everything in moderation.


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[ct_corey]

downshifting and downshifting to slow down similar to using the brakes are 2 very different things. Every auto obviously downshifts. If you use manual mode and down shift into a high rpm to slow the truck, then that is bad for the trans.  Your still putting force on the trans and internals.