Fuel consumption - your opinions please.

Homer · Post by **Homer** » 22 May 2005, 00:56

I recently purchased a Peugeot 807 2.0 HDi with a manual gearbox.
The official fuel consumption figures are something like 30mpg urban, 40 mpg combined and 47mpg extra-urban.
So far, after over 1000 miles we are struggling to achieve 30mpg overall (last tankfull averaged a little over 26 mpg). This includes some long trips and some local driving.
Admittedly both myself and the wife don't hang around but with our previous cars we have always got roughly the official combined mpg figure. Last car was a Xantia 2.0 Turbo (petrol) estate. Before that we had a 2.0 8v Xantia saloon, before that several petrol BXs (1.6 and 1.9 engines).
So do you think there may be a problem with the car or do you think it's just our lead footed driving?

Kowalski · Post by **Kowalski** » 22 May 2005, 01:36

There are lots of things that can damage your fuel economy, flat tyres, blocked exhaust, binding brakes etc etc. If the car goes OK and performs as it should, in all likelyhood there isn't a whole lot wrong with it.
On the one hand 26mpg is pathetic economy for a HDI engined car, even Berlingos manage the 40s where as Xsaras and Xantias I'm told can do reach the 50s. On the other hand it's a big heavy car and not so aerodynamic either. Check the obvious that I've listed above and if it's none of them I'm a little clueless. My TD Xantia once got down to 35mpg over a tank of fuel, but it did have a pretty bad fuel leak at the time, I'd check to see whether you have the same.

Robin · Post by **Robin** » 22 May 2005, 02:53

Does the 807 have a trip computer and cruise control?
If so try using the trip computer to verify the MPG and if you have cruise control try a longish run from a reset computer and cruise control set to say 60 mph on a motorway or dual carriage way and see what it reads.
As a matter of interest I have just completed a series and eight runs from Cambridge to York on the A1 in a variety of weathers. Using cruise control when ever possible at a steady 70. The average mpg varied from 37 to 46. (2.5 XM TD for comparison.)
Good luck with the searches. Robin

Homer · Post by **Homer** » 22 May 2005, 03:07

Checked tyre pressures and it rolls out of the garage if I just let off the handbrake so I don't think the brakes are binding.
I wasn't expecting it to be very quick but it seems OK performance wise. It keeps up with all but the fastest traffic and pulling away doesn't seem too bad at all even compared to the Xantia. It runs out of steam at about 3500prm and won't do anything past 4000 (the wife has no mechanical sympathy [;)] ) but that's about what I expected.
Fuel leak, hmmmm, no smell but I will consider it. Blocked exhaust? another thing for me to think about but I'm not sure how I would.
It had a full service when I bought it but I don't have much faith in dealers.
Yes it is big and heavy it's just the fact I'm getting nowhere near the worst official figures that worries me. Still with an 80L tank I'm not filling up as often, just spending longer doing it. [:p] For comparison my brother has a VW Sharan 1.9 TDi (95bhp?) auto and gets 33mpg out of it.
We are going away next week and if it doesn't improve then I'm going to take it in but if Peugeot dealers are anywhere near as good as Citroen ones I don't expect them to come up with anything.

Homer · Post by **Homer** » 22 May 2005, 03:17

<blockquote id="quote">quote:<hr height="1" noshade id="quote">Originally posted by Robin

Does the 807 have a trip computer and cruise control?
If so try using the trip computer to verify the MPG<hr height="1" noshade id="quote"></blockquote id="quote">
Yes, the computer agrees with my calculator, unless of course the mileometer isn't reading correctly. Something else I shall check though it seems about right.
<blockquote id="quote">quote:<hr height="1" noshade id="quote">if you have cruise control try a longish run from a reset computer and cruise control set to say 60 mph on a motorway or dual carriage way and see what it reads.<hr height="1" noshade id="quote"></blockquote id="quote">
It does have CC so I might pop out overnight and try that, it's the only time the roads are quiet enough to use it.
On the flat with a very light throttle at about 50mph it will show good readings, in the 50s or 60s but if you so much as look at the accelerator they drop to the low 20s. Pulling away in 1st it will read between 9 and 10 less acceleration doesn't change that much, maybe hit 12 but for a much longer time.

howiedean · Post by **howiedean** » 22 May 2005, 15:02

Hi,
I've noticed that my Xantia HDI MPG varies much more than that my ZX. In the Xantia on long motorway runs I've managed 46 mpg whilst cruising at 80+ miles an hour. The ZX seems to manage 37-40 no matter how you drive it.
Cheers

Paulmi16 · Post by **Paulmi16** » 22 May 2005, 16:27

With limited experience of turbo diesels, Xantia 1.9td and Peugeot 309td the fuel economy is great until the turbo is spinning, and after that the economy falls dramatically. In the end the 309 when driven hard was no better on fuel than the 306 2.0 petrol we have now.
Paul.

tomsheppard · Post by **tomsheppard** » 22 May 2005, 16:47

'tis true, alas. Turbodiesels are the worst of both worlds, going like a Diesel or drinking like a petrol. The HDI seems gutless, too, compared with earlier engines.

Kowalski · Post by **Kowalski** » 22 May 2005, 23:02

The XUD feels faster than it is because of the turbo surge, the HDI 90 has more torque pretty much anywhere in the rev range but feels slower because it's more linear.
I drove a Vectra GSI and that felt slower than the Xantia TD but was rather quicker...

turbolag · Post by **turbolag** » 24 May 2005, 18:13

Something is amiss - a friend of mine gets that out of her petrol engined version.

fastandfurryous · Post by **fastandfurryous** » 24 May 2005, 19:01

Something is very much amis... an HDI engine should not run out of puff at 3500rpm. The HDI 90 engine in a 306 revs freely to well over 4500, and delivers more torque than the 1.9TD engine. I know a 306 is significantly lighter and smaller than an 806, but I can get 50MPG from a 306 HDI without even trying.
Even my Talbot Express van, which is as aerodynamic as a house, with it's 1970's pushrod diesel engine gets between 35 and 40 MPG.

Kowalski · Post by **Kowalski** » 24 May 2005, 21:55

Are HDI engines getting old enough for faults to occur? If they are, we'll be finding out very soon how their long term durability compares to the old XUD, by the sounds of things the basic mechanicals are sound but the electronic bits, injectors and fuel pumps are going to cause all of the troubles.

turbolag · Post by **turbolag** » 24 May 2005, 21:59

Lift pumps (not that all HDi's have them) seem to be the recurring fault on high mileage HDi's, like cabs etc.

Kowalski · Post by **Kowalski** » 24 May 2005, 22:16

Why would the lift pump on an HDI be any different to the fuel pump on a petrol? I know petrol and diesel aren't exactly the same substance but they aren't a million miles apart either.

Homer · Post by **Homer** » 06 Jun 2005, 03:50

Reset the computer before we set off on holiday - it had a 22mpg average after 100 miles of mixed town and motorway driving.
Managed just over 29mpg on the way up on a very crowded M62, M1, A1 so no opportunity to give it any welly.
My brother's Sharan (1.9 TDi auto) managed just over 30mpg on the same run towing a 19 foot caravan! So something isn't right.
Overall for a week driving around country roads it returned 28.2mpg with a high point of 30.1 (which was actually achieved on the way there). the Xantia would have done better with the roofbox on.
So when I get up tomorrow afternoon I'm going to harass the dealer. They owe me some bumper trim anyway.[:(!]