| C6owners :: Forums :: C6 Support :: The Garage |
<< Previous thread | Next thread >>
|
V6 HDi Fuel Consumption |
    Please Register to enjoy additional Member Benefits |
| Author | Post | ||
tonyrome
|
|
||
  Member No: #15
|
I've been driving my C6 recently on quite a few stop-start journeys, through and around Berlin. Now, I know this is the worst time of the year for obtaining good fuel economy figures, because of the cold temperatures, but I've covered 500km (not all in town) at an average of just 13.6l/100km. For those in the UK, that's about 300 miles at 20mpg. For a diesel car! And that was not performing drag race starts from the lights, either! Just normal driving. Added to my experiences last year of high speed runs, which only appeared to average around 30mpg, it's not really looking very impressive. I know it is possible to obtain 40mpg in the summer on a very gentle run, with a flat road etc. etc. but this is not feasible very often and, the 'real' average consumption figure is not looking anything special. Of course, the new 3 litre variant is far superior in this respect but what are all you 2.7 owners seeing, in terms of fuel economy, for real world driving? |
||
|
|
|||
C6Dave
|
|
||
    Member No: #1
Location: Northumberland |
I was down to 27 mpg during the cold spell but that was because of a lot of very cold mornings where I started the car and let it idle and warm up to clear the screen before moving off - around 10-15 minutes a time Not good for mpg figures it has to be said!! Before that though it was a lot higher Tony |
||
|
|
|
||
|
michaelb
|
|
||
 Member No: #14
Location: London |
Yes, I have to admit I'm disappointed in its economy. At UK motorway speeds in September I saw 43 to 44 mpg on a long run. Over the New Year I saw 32 to 33 mpg from a long run at French Autoroute speeds - I would hate to think what that would drop to at German Autobahn speeds! It is, after all, a car weighing nearly two tons. Given that diesel is often dearer than petrol in the UK, and no matter how hard you try you always get diesel oil on your hands at every fill, this hasn't been my best introduction to the benefits of diesel motoring.  |
||
|
|
|
||
|
C6Dave
|
|
||
|
Member No: #1
Location: Northumberland |
michaelb wrote ... Yes, I have to admit I'm disappointed in its economy. ............................. Given that diesel is often dearer than petrol in the UK, and no matter how hard you try you always get diesel oil on your hands at every fill, this hasn't been my best introduction to the benefits of diesel motoring. I dread to think how much longer you would have spent at the pumps and what the mpg would be though in a petrol engined C6 |
||
|
|
|
||
urb
|
|
||
  Member No: #26
Location: Stockholm |
C6Dave wrote ... I dread to think how much longer you would have spent at the pumps and what the mpg would be though in a petrol engined C6 Strange can't see much difference in consumption from summer to winter. Could it be that the diesel has problem to keep the engine temperature up. According to the OBC 11.2l/100km the last 2500km with a average speed of 30 km/h (much in town) |
||
|
|
|
||
gmerry
|
|
||
 Member No: #21
Location: Scotland |
Tony, around town driving, cold starts, stuck in traffic etc and only averaging about 16 mph, diesel consumption is around 20mpg (indicated from the computer). I've noticed on longer trips on twisty B roads up the glens here in Scotland which means on and off the throttle, the auto is constantly changing down and the indicated instantaneous consumption drops to mid teens. This is not gunning the engine but I need to get up the hills. If I put the car into manual and make it stay in gear, on the same roads the consumption (instantaneous again) drops way down but the throttle response is sluggish. So I put the high consumption down to the way the auto gearbox is calibrated. Regards |
||
|
|
|
||
|
tonyrome
|
|
||
|
Member No: #15
|
Thanks for the responses. It sounds as though you are all achieving similar figures to me. I'll have to knock up some kind of snow guard and see if that helps, as I've been told we may be getting some temps as low as -20C in the night, over the next few days...! At least over here in Germany, the diesel is cheaper than the petrol! However, I think the cost per litre is actually higher than in the UK, due to the weakness of the pound. It's currently about 1,18 EUR (1.04 GBP) for diesel, 1,35 EUR (1.18 GBP) for unleaded, 1,45 EUR (1.27 GBP) for Super and a whopping 1.60 EUR (1.40 GBP) for 100 RON petrol! gmerry wrote ... So I put the high consumption down to the way the auto gearbox is calibrated. That's an interesting observation. I've noticed some of the things you mention with regard to the way the auto box 'hunts' and I've also resorted to using the manual gear change, to change up when the auto doesn't want to. The poor consumption around town may be related to this, although I reckon the sheer weight of the car has a lot to do with it, as well. I'll be taking some much longer trips in the coming months, including a possible 600km run next weekend and a couple of 2000-4000km journeys in the Spring and Summer, so I'll see what kind of figure I can achieve on those trips! |
||
|
|
|
||
|
tonyrome
|
|
||
|
Member No: #15
|
ps. Michael. 'some sort of dark blue'?  . It should be either Admiral Blue (solid) or Mauritius Blue (Pearl). The latter was the colour of the demo I drove - very nice.
|
||
|
|
|
||
|
gmerry
|
|
||
|
Member No: #21
Location: Scotland |
Tony, one factor you might want to consider for your fuel consumption is the age or cleanliness of the oil. Soot buildup causes a noticable increase in viscosity. For the ACEA "E" series of oils, the specification requires that the increase must be limited to less than a factor of 2.1 (viscosity increase compared to new oil). | ||
|
|
|
||
|
tonyrome
|
|
||
|
Member No: #15
|
gmerry wrote ... one factor you might want to consider for your fuel consumption is the age or cleanliness of the oil. True, but I had new oil and filter in August, followed by a full 20K service, including new oil and filter again, in November! Since Citroen are talking about 2 year service intervals, I think I'm just inside of that 
|
||
|
|
|
||
|
gmerry
|
|
||
|
Member No: #21
Location: Scotland |
Tony, I think that particular issue does not apply in your case!!!. However, I think we should keep on looking. Do you know any other cars that use the same 6 speed auto? Maybe we should try and see what consumption they get. Regards |
||
|
|
|
||
|
tonyrome
|
|
||
|
Member No: #15
|
gmerry wrote ... Do you know any other cars that use the same 6 speed auto? Maybe we should try and see what consumption they get. The exact same gearbox? The new C5 would be one and that also had the 2.7 HDi initially. Consumption was only slightly better than the C6, probably due to a small weight saving. Did Peugeot use the same gearbox? The Jaguar S-Type, XJ and XF all used the same 2.7 HDi a few years ago but I think the gearbox was different. The fuel consumption for the XJ was good but probably because it was made of aluminium and therefore much lighter. Since I originally remarked about the gearbox 'hunting' for the right gear (see elsewhere on the forum), I've read several reviews which mention a 'hesitant' auto gearbox, so I'm pretty sure it's an issue with the 'box or the programming of it. I've also found that, whilst the in-gear shifts are very smooth, there can be a jerk when accelerating from standstill. If I let the car creep forward momentarily, ie. no acceleration and no brake, then hit the accelerator, it's smooth. But going from foot on brake to accelerator, it often lurches forward. This could also be a programming issue, so I might get the specialist to take a look when I'm next in the UK. In the meantime, I think I'll try to fashion a homemade snow guard for the grill and see if it helps with the consumption. |
||
|
|
|
||
|
pclark
|
|
||
|
Member No: #3
Location: North Yorkshire |
The C6 auto transmission is used in a wide variety of front wheel drive vehices. See link to Wikipedia page below. If this doesn't work go to Wikipedia and type 'AM6 Automatic Transmission' into the search box. - Click Here - |
||
|
|
|
||
|
michaelb
|
|
||
|
Member No: #14
Location: London |
Tnx for the link to the Wiki article. I assumed the C6 had a conventional hydraulic auto but reading this I'm confused. The author mentions clutches and pinion gears but no torque-convertor. So is the gearbox like Magneti Marelli's Selespeed? |
||
|
|
|
||
|
C6Dave
|
|
||
|
Member No: #1
Location: Northumberland |
Looking at the technical Docs the gearbox does transfer the drive via a Torque Convertor (can't post the info as I'm using a netbook atm) Will try and post more info tomorrow BTW don't rely on everything you read on wikipedia |
||
|
|
|
||
Go to page >>
|
|
 User Colour Key:Head Administrator, Administrator, C6 owner, Technical Expert, C6 Premier Discount Club |
|
Privacy Policy | Cookie Policy | Site Disclaimer | Contact Details | Warranty | Sitemap | C6 Insurance | Quick Facts | Re Call Info | Downloads | Error Codes
| Site and Graphics created by: C6Dave Forum Icons by Axialis Emotes by Seb | 
|
