Xantia fuel economy

Nikolaymk · Post by **Nikolaymk** » 02 Jul 2003, 05:03

Hi all,
I've recently purchased my first Citroen. I'm a bit disappointed by the fuel consumption though. It only returns about 32-33 mpg and that's mostly on motorways. Is it normal the revs to be around 3500 on 5th gear at 70 mph? The car has only done 50K miles and I've used STP injestor cleaner - the tyres are all good. Can I expect a big improvement after changing the air filter?
And by the way - how do I change the air filter on 1.8i Xantia?
[:)]

AndersDK · Post by **AndersDK** » 02 Jul 2003, 06:44

Low fuel mileage is mainly caused by lack of simple service.
The air filter is due at every 36Kmiles - or every 2 y's. Located on top of engine at end of large duct hose.
from Haynes :
Loosen the duct hose clip & remove hose from filter housing.
Loosen the 2 screws found on bottom of housing near duct hose stud.
Release the 2 retaining clips on top of housing - then lift off the cover.
Now you see the air filter element.
If not allready done - then replace engine oil & filter - and the spark plugs.
More on your Xantia is found here (electric schematics & some mechanical) :
http://citroeny.cz/servis/servis.htm

franciscolunn · Post by **franciscolunn** » 02 Jul 2003, 23:40

nykolaymk
i got 1.8 16v as well, same fuel economy as yours,unfortunately the xantia is quite a heavy car and takes a bit of moving altho as you know they don't hang about if pushed, anyway i'm afraid you just have to be abit soft on the accelerator at times,revs sound about right.
xantia 1.8 16v

Jonesy · Post by **Jonesy** » 02 Jul 2003, 23:49

I'm also afraid that sounds about right, they are a fairly heavy vehicle and the petrol engined models tend to be fairly low geared in my experience. Changing air filter won't improve this dramatically unless it is in a terrible state!

algieuk · Post by **algieuk** » 03 Jul 2003, 00:13

Check your speedo.....3500 revs at 70 does not sound right. IIRC they should be doing something around 24MPH per 1000 rpm in 5th gear. My speedo reads 20%slow (as does the odometer). This would mean that your indicated 70 would actually be closer to 84mph. It would also mean your fuel consumption would be closer to 38/39, which would sound more appropriate. I suspect my speedo may have been changed for a lower mileage one some time back, and there may be different drive ratios on different models. I haven't been able to confirm this yet though.

JohnD · Post by **JohnD** » 03 Jul 2003, 00:35

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by algieuk</i>
and there may be different drive ratios on different models.
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
You're right Algieuk. Of the diesel Xantias, the 2.1TD does 27.3mph at 1000rpm, the 1.9TD does 25.3mph and the 1.9 does 21.8mph. On my 2.1 the speedo and rev counter disagree about about 5%.

Nikolaymk · Post by **Nikolaymk** » 03 Jul 2003, 01:45

Thanks for the info. The speedo of my car is definitely not changed and the mileage is correct. If the speedo was not showing the correct speed I would probably be flashed by the cameras unitil now

. And it'sa petrol - not a diesel model. I know from experience that the diesel cars work on lower revs. Well, most of then anyway.

Homer · Post by **Homer** » 03 Jul 2003, 02:02

Sounds about the same as the 2.0 8v I had. Best economy I ever got was about 36mpg, that was on a long run down the A9 with heavyish traffic keeping me to under 60mph. I do remember being a bit concerened about pulling 4000rpm all the time on the motorway when I first got the car.
5th gear is low compared to a lot of other cars which means you don't have to change down so often but it does keep the revs pretty high.

algieuk · Post by **algieuk** » 03 Jul 2003, 02:43

Thanks John. Explains a lot. I have a 1.9D, and it is definitelydoing over seventy at 3000rpm. The speedo indicates 60ish. I seem to have turbo ratios for some reason. Maybe the gearbox was changed for a turbo gearbox at some time in the past. All I have to do now is work out is it the gearbox speedo drive or the speedo head that i need to change to get it right

Jonesy · Post by **Jonesy** » 03 Jul 2003, 03:48

Don't forget that diesels only rev to about 4,400 rpm, most of the petrol engines, especially the multivalve units are only just getting into their stride at this point.
I had a BX GTI that was geared about the same (i.e. 20 mph/1000 rpm) and that did about 33 mpg on a run if you were reasonably gentle.

MW · Post by MW » 03 Jul 2003, 22:41

I must be doing something right. My 16v 1.8 (90K) has always turned in somewhere around the 37 mpg mark, and often nearer 39 on long A road runs. In France, loaded to the gunwales, I regularly get 525 miles out of a tankful. Unless my odometer's playing up, that is.....
Anyway, 3500 revs at 70 mph sounds about right.

reffro · Post by **reffro** » 03 Jul 2003, 22:52

Well I'm glad my 2.0 8V auto isn't geared that low, otherwise my fuel economy would drop through the floor. Mine shows 75mph at 3000rpm, and gives 33mpg at best cruising at 70-75mph on the motorway.

JoSawday · Post by **JoSawday** » 04 Jul 2003, 00:58

Just to add my 2 penn'th - My 126,000 mile Xantia 1.8 16v has averaged about 36-37mpg over it's life. Mostly clocked up on a 40 mile commute. Having the air con on makes little differnce.
I do suspect the speedo though. Travelling behind my wifes old Fiesta the Xantia displays 52 to her 60 and 60 to her 70 (checking via mobile phones - tut tut). Never did sus out which was more in error. Eprhaps we'll try the experiment again with her new Picasso.

David Goddard · Post by **David Goddard** » 04 Jul 2003, 02:13

Checked my Xantia using a GPS receiver. When the GPS shows 70MPH, the speedo reads 74MPH. (GPS is accurate to 0.1MPH)

algieuk · Post by **algieuk** » 04 Jul 2003, 02:30

When you check the speedo, check the odometer too. That is mechanically geared. If that is in error then there is something wrong with the drive ratios.