AM6 transmission economy

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GiveMeABreak
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Re: Just how "bad" is the EGS Gearbox?

Post by GiveMeABreak »

talbotsteve wrote:
25 Dec 2018, 23:14
So poor fuel economy is just down to it being a fully automatic gearbox then?
Not so much these days - Autos generally today have more forward gears than manuals so they can provide that power to the car at lower engine speeds. The AM6 is a six speed Auto box. The current manual boxes fitted to a lot of PSA cars are 6 speed (depending on engine type and size). But some of the new generation of PSA Automatic boxes are 8 speed, so will be more economical.

Having said all that, when comparing the 2.0 HDi 138 engines below, one with Manual 6 speed and the other an Auto 6 speed, you can see the Auto fares poorer both in consumption and emissions: These are the official PSA figures for the C5 X7 2008 on for the engines specified.
-Marketed versions2.0 HDi 138 hp BVM
(Manual 6 Speed)
2.0 HDi 138 hp BVA
(6 Speed Automatic)
-Engines: - gearboxDW10BTED4 - ML6CDW10BTED4 - AM6
Urban (EEC)Consumption (L/100km)7,99,9
CO2 emissions (in g/100 km)209262
Extra urban (EEC)Consumption (L/100km)4,95,5
CO2 emissions (in g/100 km)129146
Combined (EEC)Consumption (L/100km)6,07,1
CO2 emissions (in g/100 km)157189
talbotsteve
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Re: Just how "bad" is the EGS Gearbox?

Post by talbotsteve »

If driven briskly it manages around 20-25mpg, when driven extremely frugally not over 50mph very light throttle it only just creeps into the 30's. It is the Lounge version so may be heavier?
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Re: Just how "bad" is the EGS Gearbox?

Post by GiveMeABreak »

I should of done this in the first place, but here are the official consumption figures for your C4 Picasso model (at the end) - I've included the 1.6 HDi engines and the same engine as you but with the piloted gearbox (Sensodrive) shown before yours, so you have a comparison. :-D

Note: I've converted the L/100KM into MPG in brackets and in red for your car.
BlankMarketed versions1.6 HDi - manual gearbox - 5-speed1.6 HDi - SensoDrive - 6-speed2.0 HDi - SensoDrive - 6-speed2.0 HDi - automatic gearbox - 6-speed
CycleEngines: - gearboxDV6TED4 - BE4/5LDV6TED4 - MCPDW10BTED4 - MCPDW10BTED4 - AM6C
Urban (EEC)Consumption (L/100km)7,3 (38.69)6,8 (41.54) 7,9 (35.75)9,9 (28.53)
CO2 emissions (in g/100 km)190176206262
Extra urban (EEC)Consumption (L/100km)5,1 (55.38)5,1 (55.38)5,1 (55.38)5,9 (47.87)
CO2 emissions (in g/100 km)135135132156
Combined (EEC)Consumption (L/100km)5,9 (47.87)5,7 (49.55)6,1 (46.30)7,4 (38.17)
CO2 emissions (in g/100 km)155150158195
So other things that can make a difference - fuel quality (avoid supermarket fuels), tyres (low rolling resistance will increase MPG) and ensuring they are inflated to the right pressures , carrying excess weight about (toolboxes, handbags (suitcases more like :roll: ) etc. and light foot approach, Air conditioning (or climate control if fitted which uses the A/C) can reduce fuel economy too. But importantly, the roads and how hilly is it where you travel. Where I am, it is all hills in the Welsh countryside, so with my 2.0 HDi, same engine, I only get 38-42 tops on my 6-speed manual. On a motorway trip it shoots up to the mid to high 50s.
talbotsteve
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Re: Just how "bad" is the EGS Gearbox?

Post by talbotsteve »

Cheers Mark, hills are the bane of my life in west Cumbria, nothing but hills unfortunately.
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Re: Just how "bad" is the EGS Gearbox?

Post by talbotsteve »

Why would my CO2 emmissions be so high compared to the same engine in the senso drive? Surely the engines at similar revs should be the same?
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Re: Just how "bad" is the EGS Gearbox?

Post by GiveMeABreak »

It's the same with the C5 X7 - my friend has the same engine as me, but has the AM6 Auto box and his emissions are way above mine, that it puts his car into the next car tax bracket!

A lot of this has to do with the weight according to PSA:
NEDC Protocol.PNG
Transmission Type Effects
Despite significant technical progress, automatic gearboxes continue to have higher fuel consumption than manual ones. the gap between the nedc test and Protocol results is also greater for automatic transmission, particularly in urban driving conditions (Figure 22).

Higher gaps between manual and automatic transmission occur for both gasoline and diesel powertrains and can be as much as 3 l/100km for an automatic diesel car in urban driving (Figure 23). Improving the operation of automatic gearboxes fitted to diesel engines would reduce the performance gap identified in Figure 16 and Figure 17. Higher average vehicle weight might partly explain these differences, with weight being an important driver of fuel economy in urban environments.
NEDC: New European Driving Cycle
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EDC5
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Re: Just how "bad" is the EGS Gearbox?

Post by EDC5 »

I’d like to add that the AM6 is a nightmare for fuel consumption around town. Doing mainly short journeys through the city I managed 17mpg on my 2008 2.0 HDi with the AM6.

Even on slightly faster roads it seems reluctant to lock up the torque converter until you’re doing about 45 or so. Why, I don’t know, but the gearbox software has definitely been mapped for smoothness over efficiency.

And yes, as Marc mentioned earlier, I pay a horrendous amount in car tax for the privilege of poorer fuel economy :oops:

I can’t complain though, I knew what I was getting when I bought it.
talbotsteve
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Re: Just how "bad" is the EGS Gearbox?

Post by talbotsteve »

can the box not be remapped?
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Re: Just how "bad" is the EGS Gearbox?

Post by talbotsteve »

I did ask this not sure if anyone noticed it but.

Another question is, how hard would it be to convert to manual? I'm guessing Clutch, Flywheel, Gearbox, Peddle assembly, Clutch cable.
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Re: Just how "bad" is the EGS Gearbox?

Post by crapday69 »

Cheaper selling and buying a manual car.
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Re: Just how "bad" is the EGS Gearbox?

Post by GiveMeABreak »

Yes, it's not just that, but the ECUs, electronics and programming / ESP, EPB all has to be changed, centre console, dashboard is different - really a non starter...
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Re: Just how "bad" is the EGS Gearbox?

Post by Hell Razor5543 »

GiveMeABreak wrote:
26 Dec 2018, 23:54
really a non starter...

Which is why he wants to replace the bl00dy thing! :D

talbotsteve
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Re: Just how "bad" is the EGS Gearbox?

Post by talbotsteve »

Not so easy when I have 4 years of finance left on a car I can't afford to run :-(
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Re: Just how "bad" is the EGS Gearbox?

Post by GiveMeABreak »

Yes, it's a shame and another reason for the need for those 'real world driving' consumption figures that should of been provided years ago as I've never had any yet that have matched the supposed MPG figures.

Running a petrol XM turbo was bad enough, so switched to diesels after my third XM and have stuck with them ever since. Hell of a difference in the pocket, but they do need regular servicing.

Have you considered handing it back and walking away - maybe getting something a bit more frugal in the MPG department?
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Re: AM6 transmission economy

Post by xantia_v6 »

I have split this topic from the EGS topic to avoid confusion