Menu toggle

981 PDK Gripe ... Get A Manual Or Adapt

daro911

PCGB Member
Member
FREEWHEELING

Chris Harris thinks he may actually have found something wrong with the new Boxster!


Decoupling. Get used to it, it's a phrase you're going to read with increasing frequency over the coming years.

Decoupling is a simple concept - quite simply disengaging the gearbox input from the motor and allowing a car to coast without the interia of engine internals. It's nothing new, our ancestors spent endless hours coasting their early motor vehicles down slopes in an effort to reduce fuel consumption, but it does have a marked effect on efficiency.


Clever, yes, but it ruins motorway flowI've just spent a week decoupling in a new Boxster, and I bloody hated it.

I hadn't realised just how much store I set by being able to accurately judge a car's coasting characteristics with a gear engaged - normally the longest ratio on a motorway. You know the stuff, maintaining progress without using the brakes by anticipating and keeping a view as far ahead as possible. Well, now I do, because de-coupling kind of wrecks normal progress using this method.

On level ground, or a slight downhill section, you feel the powertrain release pretty much instantaneously as you back off the throttle. The trouble is, your brain expects a certain amount of residual deceleration at this point, and it never arrives - it's a bit like falling of a track onto wet grass, that sensation of almost accelerating again as you hit the green stuff. Of course you can adjust for this, but it takes time and distance, which isn't always available on a British motorway. Also, if the car(s) ahead of you are coasting, you have so much less friction that you inevitably catch them and have to brake. Irritating.

Re-engagement is a little sloppy too: there's a definite jolt in the car, and you have to judge the reapplication of throttle very carefully - too much and you'll encourage the gearbox to kick-down, which is most unseemly.


Thankfully you can decouple the decouplingThe economy gains are undeniable. I was averaging an easy 35mpg in the 2.7 litre Boxster PDK, a staggering achievement from a 170mph roadster, but the cost to serene progress on the Motorway was simply too great.

The upside was I thought I'd found a real gremlin in the otherwise impregnable Boxster package, but that proved to be unfounded. By hitting the Sport button, you kill the decoupling antics and the Stop-Start function - and you get faster shifts and a raised rev-limiter. On balance, I'd live with the latter to avoid the former, but the Boxster would be pretty much perfect if there was simply a button to kill the coasting alone.

By now you know the rest about the Boxster. It's the best car Porsche makes.

 
With PDK, I would select Sport (manual) in stop/start traffic.

The other option is Adaptive Cruise. Not used the Porsche system, but have used it on a RR Ghost and it is very clever.
 
I have the same PDK system in my Macan prototype (Q3). It does take a little getting used to. For example, one releases the throttle approaching a roundabout & the car does not slow down (well not much anyway and even accelerates if there is a slight downhill slope. Very disconcerting at first, but you soon get used to it.

However, as soon as you touch the brake, the gearbox couples and one then gets engine braking. A subsequent touch of the accelerator disengages the gearbox (both) again and you resume coasting. If one keeps the accelerator pressed one resumes drive which is totally seamless, even at 70 mph.

Program sport mode and coasting is void. It is also void if one releases the throttle on a steep hill.

All this gives me 53 mpg is a big diesel SUV. Amazing.
 
"All this gives me 53 mpg is a big diesel SUV. Amazing. "

BIG SUV diesel-a Q3 really derek??[:D]

by the way was at classics on common (our home patch harpenden)on wednesday and some gorgeous ferrari spiders-i can certainly see the attraction[;)]
 
[:eek:]
ORIGINAL: dereksharpuk

I have the same PDK system in my Macan prototype (Q3). It does take a little getting used to. For example, one releases the throttle approaching a roundabout & the car does not slow down (well not much anyway and even accelerates if there is a slight downhill slope. Very disconcerting at first, but you soon get used to it.

However, as soon as you touch the brake, the gearbox couples and one then gets engine braking. A subsequent touch of the accelerator disengages the gearbox (both) again and you resume coasting. If one keeps the accelerator pressed one resumes drive which is totally seamless, even at 70 mph.

Program sport mode and coasting is void. It is also void if one releases the throttle on a steep hill.

All this gives me 53 mpg is a big diesel SUV. Amazing.

I generally like Chris Harris reviews but I think he has just done a mini Clarkson moan here because I don't recall him having a similar problem with the 991 PDK which does exactly the same procedure. Perhaps as he has said before on video the new Boxster is just so unbelievably good hence the little rant [:eek:]

When I test drove the 981S PDK for a short 30 minute blast I actually found the rev counter sitting at 800 rpm when I was doing circa 70 mph far more weird than any coasting sensation and as I use gears for slowing (I know thats not pc these days) I never experienced the problems highlighted by Mr Harris

As this coasting feature is unique to the PDK I say man up boys and get the slick 6 speed stick shift [8D]
 
Let me start by saying in that in my opinion, no-one buys a Porsche becuase of it's frugal fuel econonmy. If you want two seats and good mpg, buy a diesel Smart.

Having said that, on a recent trip to the Porsche Experience Centre at Silverstone, my Cayman R, (which has neither stop/start nor de-coupling) averaged 37mpg over the 160 mile round trip - about 5 mpg more than I ever got from my previous 986 Boxster S despite being a larger, more powerful engine. So the virtues of a higher ratio final gear and direct fuel injection are plain to see.

However, for me, the marginal gains available from stop/start and de-coupling don't justify the annoyance and compromises of these systems.

I bought Porsches because I love driving and love Porsches. If it has reasonable fuel economy it's a bonus, but first and foremost it has to provide fun and driving pleasure.

ps. For anyone who has a session booked at the PEC, not only will you love it but you'll come away with a better sense of what these vehicles can really do, (when you're not trying to eek out as many mpg as possible), and feel confident in your own ability to handle the car in a tricky situation. Enjoy.
 
Hi Gary,

Well we are all different. If not we all would be driving Caymans... nothing wrong in that [:D]

However, I disagree. The more economical my Porsche is the happier I am., 'cos I don't have to keep stopping to fill it up. And I am a mean old git!

Additionally, I love the 'coasting mode', but am not too fussed with stop/start. It can be infuriating, but I have learnt to use it. Same with coasting. However, both can be turned off!

As for fuel consumption, there is not a Porsche (save perhaps a Cayenne turbo) that is as thirsty as my 430. But I love it just the same.

And if you are interested in what my old VC10 did to the gallon.... well a very good day would be 10 gallons to the mile (no, not 10 mpg)! Still, I could carry more than one passenger [:D]
 
Wonder if the stop/start switch also switches off coasting? I used Sport mode all the time anyway, so I never even noticed it.
 
Gary ,
whole heartedly agree recently spent a morning at the PEC , in the Turbo S , came away from there feeling 100 % satisfied of how the car can handle giving situations, just dont go over the Kick plate 20 mph more than required, Torvill and Dean sprang to mind
 

Posts made and opinions expressed are those of the individual forum members

Use of the Forum is subject to the Terms and Conditions

Disclaimer

The opinions expressed on this site are not necessarily those of the Club, who shall have no liability in respect of them or the accuracy of the content. The Club assumes no responsibility for any effects arising from errors or omissions.

Porsche Club Great Britain gives no warranties, guarantees or assurances and makes no representations or recommendations regarding any goods or services advertised on this site. It is the responsibility of visitors to satisfy themselves that goods and/or services supplied by any advertiser are bona fide and in no instance can the Porsche Club Great Britain be held responsible.

When responding to advertisements please ensure that you satisfy yourself of any applicable call charges on numbers not prefixed by usual "landline" STD Codes. Information can be obtained from the operator or the white pages. Before giving out ANY information regarding cars, or any other items for sale, please satisfy yourself that any potential purchaser is bona fide.

Directors of the Board of Porsche Club GB, Club Office Staff, Register Secretaries and Regional Organisers are often requested by Club members to provide information on matters connected with their cars and other matters referred to in the Club Rules. Such information, advice and assistance provided by such persons is given in good faith and is based on the personal experience and knowledge of the individual concerned.

Neither Porsche Club GB, nor any of the aforementioned, shall be under any liability in respect of any such information, advice or assistance given to members. Members are advised to consult qualified specialists for information, advice and assistance on matters connected with their cars at all times.

Back
Top