paddle shifter
02-08-09, 10:42 AM
#17
yeah keep in mind the dealership said it was cool with using the paddleshifting as long as you dont work the engine too crazy, which I dont. its great for crazy traffic, and constant stops. You guys should know. And i never redline. I'm just trying to keep the brakes in great shape and see how long it will last. 
Kurtz is so smart 
. I would suggest using brakes to slow down. You don't want to have to replace your transmission or other parts of your drivetrain. heaven knows it will probably break RIGHT AFTER your warranty runs out and you'll have to spend like 10,000 dollars at a Lexus Service Dept. That would make for a very sad day lol
. I would suggest using brakes to slow down. You don't want to have to replace your transmission or other parts of your drivetrain. heaven knows it will probably break RIGHT AFTER your warranty runs out and you'll have to spend like 10,000 dollars at a Lexus Service Dept. That would make for a very sad day lol
02-08-09, 11:14 AM
#18
Lexus Test Driver
iTrader: (1)
Join Date: Jun 2008
Location: NYC
Posts: 1,124
Likes: 0
Received 0 Likes
on
0 Posts
I've always wondered how the paddle shifters work, since I never use them. Very informative read Kurtz. Thanks for clarifying
Bear in mind, no matter what they're called, those aren't actually shifters.
The only thing sport mode does is set a top gear limiter.
Normally your car is a 6 speed automatic, and it will, based on what the shift maps in the TCU say, shift gears between all 6 available gears based on speed/rpm/etc
When you move the lever into S mode you set a top gear limit of 4 (that's why 4 now displays on the dash) but the car is -still- shifting all on its own, automatically, between those 4 gears, based on what the TCU tells it.
If you move the paddle or stick to change that 4 to a 3 then it's STILL shifting all on its own, automatically, between now the 3 gears available to it (1, 2, and 3).
At no point do you ever directly shift the vehicle.
And the computer is smart enough that it won't let you switch the top gear limit down to, say, 2, when you're doing 120 miles per hour.
The only thing sport mode does is set a top gear limiter.
Normally your car is a 6 speed automatic, and it will, based on what the shift maps in the TCU say, shift gears between all 6 available gears based on speed/rpm/etc
When you move the lever into S mode you set a top gear limit of 4 (that's why 4 now displays on the dash) but the car is -still- shifting all on its own, automatically, between those 4 gears, based on what the TCU tells it.
If you move the paddle or stick to change that 4 to a 3 then it's STILL shifting all on its own, automatically, between now the 3 gears available to it (1, 2, and 3).
At no point do you ever directly shift the vehicle.
And the computer is smart enough that it won't let you switch the top gear limit down to, say, 2, when you're doing 120 miles per hour.
02-08-09, 12:20 PM
#19
yeah keep in mind the dealership said it was cool with using the paddleshifting as long as you dont work the engine too crazy, which I dont. its great for crazy traffic, and constant stops. You guys should know. And i never redline. I'm just trying to keep the brakes in great shape and see how long it will last.
02-08-09, 03:34 PM
#20
02-08-09, 06:54 PM
#22
Pole Position
Join Date: Sep 2008
Location: Colorado
Posts: 222
Likes: 0
Received 0 Likes
on
0 Posts
I also recomend the same for a manual tranny as well. Brakes are easier and cheaper than a clutch.
02-08-09, 07:30 PM
#23
Yes, and that reason isn't to slow or stop the vehicle. That's what that pedal -next- to the gas is for.
, and i'm going to continue to use it and drive the hell out of this car. Consider this, i didnt just get my license and been driving forever. I think I would know what the car is capable of doing and not doing. But anything can and will probably happen. You can be the safest and smallest person out there, but experience is knowledge.
I agree. And everyone with experience is telling you not to do what you're doing, except the guy who stands to make thousands of dollars when you need your transmission replaced.
There was an entire 3-page thread about this topic a while back, with virtually everyone agreeing engine braking in normal driving is a poor idea compared to just using the actual brakes.
Here's Lance Wolrabs description of some of the negative impacts of using the transmission instead of the brakes:
Downshifting instead of braking is bad. It sucks oil up past the rings, puts unnecessary high tensile loads on the rods, wears the clutch harder, or in the case of an automatic, unnecessarily raises the fluid temperature and stresses the Sprague clutches unnecessarily.
02-08-09, 07:41 PM
#24
Lexus Test Driver
Join Date: Oct 2006
Location: Dallas, TX
Posts: 1,170
Likes: 0
Received 0 Likes
on
0 Posts
02-08-09, 07:47 PM
#25
Lexus Fanatic
actually... no your not, your just giving the trans another gear with which to select from... try hold the pedal to the metal and upshift manually early say at 5k yet continuing to hold the accelerator, it will not shift untill 'it' decides too~
02-08-09, 07:47 PM
#26
The paddles aren't connected to the transmission -at all-
They're connected to the computer, and they control the highest gear you're letting the TCU automatically shift the car into. That's all they control.
Sometimes this can cause the illusion of you "shifting" the car if you it happens under just the right conditions, but in no case are you directly engaging the transmission to do anything at all like you would be on a manual (or even a more advanced auto like the IS-F)
Again, the paddles just let you change the car from a 6-speed auto into a "whatever speed you select as the highest gear" auto. The TCU still controls all the actual shifting.
Once you move from 2->3 you're just telling the TCU it's ok to go as high as 3. If your rpms are high enough that it'd use 3rd, it'll do so. If they're not it'll stay in 1 or 2, whatever the TCU maps say is appropriate for speed and rpms at the time.
02-08-09, 08:27 PM
#29
Do you understand the difference between an immediate part failure and a long term failure?
The problems you are causing by engine braking don't make parts fall off the car the second you do it... it'll take years to destroy parts of the drive train in most cases.
Which is great if your cars are disposable and you dump them on some other poor sucker every 3.9 years and hope he loses your phone number.
Not so great when you need to drop $5000 on a new transmission 6 months after your warranty is up because you tried to save $200 on brakes though.
This isn't a new concept- Folks with manuals who refuse to learn how to stop their car properly have been ignoring the advice from people who know what they're doing, "brakes are cheaper than clutches", for years.
Now with the advent of manu-matics the rest of the world gets in on the fun, and can learn the same lesson with even more expensive parts than a clutch at risk. You can learn it cheaply or not, your choice.
Last edited by Kurtz; 02-08-09 at 08:31 PM.
02-08-09, 08:50 PM
#30
Lexus Test Driver
Join Date: Oct 2006
Location: Dallas, TX
Posts: 1,170
Likes: 0
Received 0 Likes
on
0 Posts
That's correct. The TCU is shifting it to 3rd, and NOT immediately if you've got it floored either since the shift point is higher than that...just like it would have done if you had left it in auto mode and hit the gas.
The paddles aren't connected to the transmission -at all-
They're connected to the computer, and they control the highest gear you're letting the TCU automatically shift the car into. That's all they control.
Sometimes this can cause the illusion of you "shifting" the car if you it happens under just the right conditions, but in no case are you directly engaging the transmission to do anything at all like you would be on a manual (or even a more advanced auto like the IS-F)
Again, the paddles just let you change the car from a 6-speed auto into a "whatever speed you select as the highest gear" auto. The TCU still controls all the actual shifting.
Once you move from 2->3 you're just telling the TCU it's ok to go as high as 3. If your rpms are high enough that it'd use 3rd, it'll do so. If they're not it'll stay in 1 or 2, whatever the TCU maps say is appropriate for speed and rpms at the time.
The paddles aren't connected to the transmission -at all-
They're connected to the computer, and they control the highest gear you're letting the TCU automatically shift the car into. That's all they control.
Sometimes this can cause the illusion of you "shifting" the car if you it happens under just the right conditions, but in no case are you directly engaging the transmission to do anything at all like you would be on a manual (or even a more advanced auto like the IS-F)
Again, the paddles just let you change the car from a 6-speed auto into a "whatever speed you select as the highest gear" auto. The TCU still controls all the actual shifting.
Once you move from 2->3 you're just telling the TCU it's ok to go as high as 3. If your rpms are high enough that it'd use 3rd, it'll do so. If they're not it'll stay in 1 or 2, whatever the TCU maps say is appropriate for speed and rpms at the time.