Sick of touchscreens in cars? Maybe good news is coming.
- Thread starter Tony Lockhart
- Start date
clivem2
pfm Member
Modern driving advice is often that we should use brakes for reducing speed. The thinking is that descending a long hill using engine braking stresses the transmission and that it’s cheaper and easier to replace brakes than vs an auto box. I certainly use the paddle shifter when on ice, though this happens rarely nowadays in the area we both live in.
Whether engine braking is indeed less economic…I’m not qualified to pronounce on.
Sue Pertwee-Tyr
Accuphase all the way down
I’ve descended hills behind people who ride the brakes all the way down - I call them brake-botherers. I think there’s a trade off between risking overheating brakes, so they are less effective right when you need them most, and stressing the transmission.
clivem2
pfm Member
Certainly in a manual I use engine braking. When I think about how I drive my auto, I use a combination of engine and brakes on long downhills, so this is a combination of paddles and left pedal. I agree about being concerned about overheating the pads…plus coating my wheels too much in dust. Most people though don’t find manually controlling an auto box something they think of.
What was in my mind was that decades ago we were taught to engine brake, nowadays it seems to be much less promoted or even frowned upon.
Sue Pertwee-Tyr
Accuphase all the way down
The argument I have heard is that it is easier and cheaper to replace pads and discs than to replace a clutch. So engine braking that stresses a clutch is false economy. Not sure I buy the idea that a long downhill in a lower gear is stressing a clutch if it isn’t slipping, and especially not a torque converter auto box (unless it overheats, perhaps).
gez
pfm Member
Really? Only people I've ever seen claim it causes excess wear on the engine and transmission are people who know nothing about how engines work*. (or people who still believe car oil should be changed every six months/3,000 miles no matter what). A cars transmission system is designed to take the stress and strain of at least a hundred thousand miles of full throttle acceleration and deceleration. In fact they are over engineered to do so with a margin over and above the stress and strains required in normal use, as is every single mechanical engineered product. Ask youself this: when was the last time you ever heard of a stock car engine/transmission that could not take significantly more power than the vehicle produces out of the factory? Never is when, and in fact modern vehicles are far more capable of handling extra power than cars 40 years were. If transmissions were engineered to be so borderline that a tiny bit of extra stress caused them to fail significantly early, then you would never be able to tune any production car, and that's simply not the case, ever. Anyway, that's irrelevant because there is no more stress on an engine or transmission system under an engine braking scenario than there is under hard acceleration.
*or people who for some bizare reason believe an engine/transmission system of a car should last 300,000 miles, or else they're badly made. Which is just ridiculous.
Don't believe me, believe an actual engineer:
martin clark
pinko bodger
Agree.
And any car built in the last 20yrs + cut's off the fuel injection (saving only enough, to stop it stalling) in 'over-run.'
Torque converter auto boxes have oil/water intercoolers, and the cooling system on any car is already up to shedding 100s of HP as heat.
One aside though - is torque converter automatics in such use (and likely also, DSG boxes)
The reason you should not tow these for more than a very limited distance, is that the very-essential oil pump that pressurises the actuation and internal fluid circulation for lube and cooling, is driven from the engine-input side, obviously. So - it only remains working while driven from the output shaft providing the system is up to pressure already, enought ot pass such drive in the reverse direction. Hence the 'don't tow more than... (very small) distance' warnings.
Then again the UK is flat enough, you'll likely never have a downhill long enough, to imperil things. Elsewhere, such as the US, that might well not be true.
Cav
pfm Member
A mindreading gearbox in a car?
Modern trucks do learn how a driver on a regular route uses the gears, and where, based on gps location. The truck will then select the appropriate gear as it approaches that location. So the technology is there. If you drove the same route frequently it works well enough but is of no help on unfamiliar routes.
Sue Pertwee-Tyr
Accuphase all the way down
Cav
pfm Member
I was relying to your complaint, if that was what it was, that your autobox did not downshift when you were going downhill.
I did not say any gearbox is "flawless"; it more likely the user is expecting too much or using it incorrectly.
Colin L
High-tech low-life
My Volvo XC60 shifts into a lower gear when going steeply downhill. There must be a level sensor in it. It surprised me TBH. As it’s a hybrid I usually put it into regenerative braking mode too which slows it down nicely.
In my manual cars I always use low gears and engine braking over using the brakes. The idea that this would damage the engine or clutch seems daft.
In my manual cars I always use low gears and engine braking over using the brakes. The idea that this would damage the engine or clutch seems daft.
Sue Pertwee-Tyr
Accuphase all the way down
You didn’t, somebody else did. You then interposed yourself into that exchange and seem to have gotten the idea that we disagree. I’m not sure we do. I know you can manually select a lower gear, and I do. My contention is merely that if, as was asserted, auto boxes are already flawless, there would be no need to.
Bananahead
pfm Member
I'm not sure what flawless means. However, my Audi DSG box does do engine braking in the same way that I would. And it also seems to choose gears sensibly. I have no complaints, and it is my fourth DSG box in a row - 14 years.
Tony Lockhart
Avoiding Stress, at Every Opportunity
This horrible XC40 courtesy car I have at the moment is a mild hybrid, 2.0 petrol. One thing it does ok is, if it’s at or below the speed limit, it controls the speed while going down hill. I don’t mind that, especially in a 30 zone.
Advanced driving: when going down hill with the speed being controlled by a low gear, keep an eye on the interior mirror. If another vehicle is approaching, flash the brake lights on for a second or two. You never really know how much attention they’re paying to the road ahead.
And: when going down Rosedale Chimney or Wrynose Pass, low speed AND low gear, and most probably brakes too.
I wonder if engine breaking torquing up a dual mass flywheel the other way does it any harm? I don’t know, but it’s the only component I can think in the drivetrain which could possibly (but well might not be) affected.
Touch screens are awful (to be address the original point) they are purely a cost saving exercise. A screen and hardware buttons are much better. Existing tech, a flexible screen with haptic ‘electric braille’ type raiseable surface behind it so when you display a button a tactile raised section appears behind the screen and you can feel it, then push it through the flexible screen with a click.
Touch screens are awful (to be address the original point) they are purely a cost saving exercise. A screen and hardware buttons are much better. Existing tech, a flexible screen with haptic ‘electric braille’ type raiseable surface behind it so when you display a button a tactile raised section appears behind the screen and you can feel it, then push it through the flexible screen with a click.
flatpopely
Prog Rock/Moderator
ZF8 is close to flawless.
Tony Lockhart
Avoiding Stress, at Every Opportunity
Maybe because some people are stuck in the 1960s? Or they’re just wrong?
Most driving courses teach “Gears go, brakes slow” but once past the learning stage, sensible use of engine braking where appropriate is a good thing.
For example, don’t approach a t-junction in your 3.0 Jag S Type in the snow, ignoring your passenger’s pleas (my pleas) to slow down ages ago because the t-junction was over a brow and we didn’t know how bad the snow was over the brow… and then knock the slush-box down a gear. The back end predictably began snaking, and that was the only time in my life I’ve shut my eyes and accepted my fate.
Live and learn!