Accelerator hill-hold with dry dual-clutch auto

[y_p_w]

My dad does something I find really annoying. He likes to hold at a red light or stop sign on a hill by stepping on the accelerator. I was taught in driver ed that this is stupid since it doesn't anything more than waste fuel.

His current vehicle has the infamous Nissan CVT. I guess it does work to some extent, but I'm wondering what would happen if he got one of the newer dry dual-clutch autos. This seems to be a real hard habit for him to break, and he acts like I'm an idiot when I tell him not to do it. But if he tried that in a new dual-clutch car, how quickly could it destroy a clutch?

 

[SatinSilver]

You let him know about the issue so you did your part. Now it's up to him on whether to change his behavior or keep doing the annoying habit. Plus it's his car and he can do as he pleases. Some car owners take their car to the drag strip which is even harder on the car than what your dad is doing.

I'd be more concerned about the additional wear on the trans than the extra fuel consumption.

 

[OneEyeJack]

Anything that might even remotely be considered abuse should never be considered with a CVT. Some or many of them have difficulty working at all over their expected life cycle.

 

[Jetronic]

the dual dry clutch wouldgo into limp mode after a short while, forcing you to let the clutch pack cool. still, not an adviseable practice even with the nannies in place.

 

[supton]

I thought most CVT's still had some sort of torque convertor, for take-off?

I'd think holding on a hill, with a torque convertor (or fluid coupler), would just heat up fluid. Which can be handled. A wet clutch, it's still wear and heat, but probably not that bad. A dry clutch though, that is wear.

How long will it last under this? Between 1 mile and 250k is my bet. You know how we get into arguments about how you should never shift through all the gears, while decelerating, in a manual trans? or in an automatic for the matter? 'cuz it increases wear. Yet someone will point out that they always do so, and routinely go 300k on the same clutch/trans/etc. Doing this several times an hour vs once a week is a major difference, as is doing it for a few seconds vs several minutes at a time. Also: not everyone drives a vehicle for 20yr and 500k. 5 and done sorts of folks might never have a problem.

 

[totegoat]

I was taught to hold an auto on a hill with the brake and to shift a stick into neutral and hold with the brake. My Dad did not abide riding a clutch for any reason.

 

[JTK]

With the CVT, it's just like a conventional automatic in this type of "hill-hold" situation. The torque converter does the 'slipping'. Like you say, with these automatic shift manuals, the clutch lining does the slipping.

Somewhat related, but we've got some new Freightliner tractors at work with 10spd "automatics". Real weird stopping to pull up a loading ramp, or trying to be gentile when drop/hooking.

 

[HemiHawk]

Well its not good... that's why those cars have the hill-hold brake feature. You are just burning up the clutches. and in the dry clutch cars they are less tolerant of that heat and friction than the wet clutch cars like DSG. But I still wouldn't do it with those either.

 

[supton]

Originally Posted By: totegoat
I was taught to hold an auto on a hill with the brake and to shift a stick into neutral and hold with the brake. My Dad did not abide riding a clutch for any reason.


back in the day, holding the clutch to the floor wore on the throwout bearing. I've read that today throwout bearings are constantly turning. I'm sure there is additional wear, but it is unlikely the same as back then. Anecdotal but my vehicles have seen "lots" of extended clutch down time, and they don't seem to be the worse for it.

 

[ARCOgraphite]

No "real" problem with Nissan CVT holding on hill with gas. It has torque converter.

He should hold learn to hold with hand brake or foot brake though.

I used to footbrake then hand brake when light was going to turn GREEN. I would hold the hand brake pawl release, then off footbrake then slip clutch as you release handbrake.

ONLY IF SOMEONE WAS RIGHT ON MY BUMPER.

OTW I would just roll back a bit as the clutch was tacking up.

 

[Kawiguy454]

in this instance a slipping clutch is like a brake dyno ...that amount of power the engine is producing gets converted to heat in the fluid coupler and the temperature spikes up rather quickly. Add to that you're not moving so the heat may not get out of the system at the same rate it is being created. Tell him your take on it then remind him again when he's paying the repair bill.

A guy I once knew had a pro stock hemi cuda. He once told me the trans fluid temp goes up 20 degrees a second while on the line torqued up to launch.

 

[raaizin]

I am not sure this is possible. When I pull in my driveway in my car i see it flash Hold in the instrument panel and car does not roll backward. Car is a 2014 911,but according to linked article this feature is found on other cars the Chevy Sonic is mentioned in article so this may be across many dual clutch vehicles

http://www.truecar.com/blog/2012/01/31/s...er-for-drivers/

 

[KrisZ]

Transmission shops need to feed their families too.