Fuel Economy

B_Draper · Post by **B_Draper** » 18 Oct 2002, 16:15

Hi All,
Regardless of whether I am driving the car hard with the turbo spinning permanently(A Roads or Motorway) or gently in town without the turbo, I alway get about 400-420 miles per tank of diesal.
Something is telling me this is not right<img src=icon_smile_sad.gif border=0 align=middle> What should I be getting and does anyone have any ideas how I can improve my economy? What does everyone else get on the XUD turbo'ed engine?
Regards !
PS: I have a '94 ZX 1.9 TD and tires are always maintained at correct pressures (Front - 35 PSI and Back - 33-35 PSI depending on load)

Chris_L · Post by **Chris_L** » 18 Oct 2002, 17:32

Hi,
Quick question - how low do you let the tank go before you fill it up? Check how much diesel you're putting in per fill-up. I'm one of those drivers who lets it go until the light's just about coming on before filling, and that way usually get about 43 litres (nearly 10 gallons) in, but if not, then you might only be putting 9 gals in. If this is true, then 420 miles isn't that bad (approx 47mpg).
I drive a 93 ZX TD (same engine as yours I think) and my fuel economy varies depending on how I drive. Last weekend I averaged 44mpg over 500 miles+, half of which was driven quite hard, and the other half quite tame. The most I've ever achieved is about 50mpg and the worst is about 35mpg. Try driving everywhere at 65mph (when you have a chance to do lots of motorway driving) and trying your best not to accelerate hard and see what you can get. The book quotes 65mpg at 56mph (but I don't have the patience to prove it!!). The thing about turbo engines is that if you take it easy, the economy is far better than the corresponding non-turbo engine (especially if like ours, you have an intercooler), but if you drive it hard and use the extra power, then you're not comparing like with like and you get less.
Hope this helps,
Chris

rory_perrett · Post by **rory_perrett** » 18 Oct 2002, 18:03

Not really comparing like with like so may be not any use to you.
BX 1.8 Turbo Diesel Estate mostly fast A road and motorway work averages 50 mpg
Xantia 1.9 Turbo Diesel averages 39 town commuting, 47 on fast A road and motorway.

rabenson · Post by **rabenson** » 18 Oct 2002, 18:22

95 ZX non-turbo diesel - 50-53 mpg (includes a LOT of dual carriageway/motorway driving)
Ron

Gaz · Post by **Gaz** » 18 Oct 2002, 18:25

Driven 1/2 to 2/3 of full power on A-roads. (50 miles per week) and 70mph 2800rpm motorways (300 miles per week). I get 46-49 mpg regularly for last 1 1/2 yrs. Tank lasts 500-520 miles, try not to empty the tank because it'll pick up the crap from the bottom of the tank. Gaz (Xantia 1.9 TD SX '93)

B_Draper · Post by **B_Draper** » 18 Oct 2002, 19:51

Thanks to all the replies so far!
Chris - I usually fill up the car when the fuelling light is on or about to come on. I then fill the car up to maximum and then top it up slightly so make sure the tank is actually full. I have a habit of not trusting the fuel pump when the car has a full tank in about 30 - 45 secs!
44-47 mpg sound approximatley right as I tend to drive the car hard (yeah, baby, yeah<img src=icon_smile_wink.gif border=0 align=middle>) for half a tank and then gently for the rest until the light comes on.
Touch wood, the car has and never will run so low, the fuel has run out then sucking in all the crap from the tank like Gaz says!
As I have recently gone back to full time education, I can't afford to fill the car back up to a full tank, so I only put in a fiver at a time which doesn't seem to get me that far!
I must learn to drive the ZX in a more elderly - opps, sorry - gentle fashion. Bah! With, of course, the occasional turbo'ed blast to clean the engine of any soot/carbon buildup!
Later - Ben

JohnD · Post by **JohnD** » 19 Oct 2002, 00:24

Hi All - Mine is a 2.1 TD estate, and I keep accurate records from month end to month end. A mixture of town and motorway driving produces a monthly average of 42. When towing the caravan at 65/70 it drops to 31mpg. The speedo/mileometer I believe reads about 4% on the high side, so the fuel figures should be corrected accordingly.

Chris Peddie · Post by **Chris Peddie** » 19 Oct 2002, 18:37

Mine is the 1.9TD in a '96 xantia, I've often wondered if I should be getting better figures that I do but haven't investigated it further. I usually get around 38-40, but have never had better than 42-44, even on long motorway jaunts. Have often wondered if with some injector reconditioning this might get better??
HTH
(another) Chris

marski · Post by **marski** » 19 Oct 2002, 19:58

i have 2 xm's.the 2.1td saloon does 41 all round,my baby the 2.5td vsx estate does 51.3 driven carefully.it used to do 48 until i put zx1 in the oil.your lighter car should return better figures.

rabenson · Post by **rabenson** » 19 Oct 2002, 21:56

Must confess I swear by putting the occasional dose of injector cleaner through - seems to keep the economy up. Certainly can't do any harm. Managed 197000 miles on original injectors on a 205 diesel (and was still getting 58 to the gallon when I sold it....)
Ron

Gavin1 · Post by **Gavin1** » 19 Oct 2002, 23:02

Interesting, I've often wondered how these poeple who get 50+ mpg achieve it, I only get about 38 - 45 mpg during 'normal' driving mixed town / motorway. I'm sure if I drove around with a flat cap on and held up the traffic I could achieve more.
In the process of tuning my engine I advanced the injection timing a little and certainly between 2 - 3000 rpm increased the torque and reduced the fuel consumption a little. The xantia is very low geared and seems even more so if you tune the engine so I imagine this doesn't help the fuel comsumption but is useful if like me you tow heavy trailers.
You have to bear in mind that this XUD engine is now quite old and not that ecomomical in comparison with modern DI engines.

ale2104p · Post by **ale2104p** » 20 Oct 2002, 19:04

I have a ZX Volcane 1.9i, and all I seem to get is about 22mpg. Wow!! wish I bought the diesel insted. Anyway what do others get on the petrol version.
Solly
Edited by - ale2104p on 20 Oct 2002 14:10:22

Adrian_Mc · Post by **Adrian_Mc** » 20 Oct 2002, 22:24

I've got two Xantia 1.9 TD, one estate and one saloon. I've never got more than about 35 mpg from either of them. I was going to buy some injector cleaner once but the guy in the shop told me I would be wasting my money (not in his best interests to say that since it was his business). I would be interested in any ideas which would improve the fuel economy. I'm going to try changing the air filters first because they both look pretty filthy.

JohnD · Post by **JohnD** » 20 Oct 2002, 23:37

You should do a bit better than 35mpg unless 1. Your journeys are all short ones. 2. They're mainly around town or 3. You're very heavy footed. If you are not sure that the air filters are clean, then change them. I disagree about the injector cleaners. I use them fairly regularly (in our four diesels) and the very low readings achieved on the MOT smoke test proves they are worthwhile.

Adrian_Mc · Post by **Adrian_Mc** » 30 Oct 2002, 02:40

<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
You should do a bit better than 35mpg unless 1. Your journeys are all short ones. 2. They're mainly around town or 3. You're very heavy footed. If you are not sure that the air filters are clean, then change them. I disagree about the injector cleaners. I use them fairly regularly (in our four diesels) and the very low readings achieved on the MOT smoke test proves they are worthwhile.

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A lot of my journeys are short, and my foot is heavy ( I used to drive a non turbo diesel and you get used to flooring the pedal), but even on long journeys of about 200 miles of motroway driving I still only get an average of 35 mpg. What additives do you use/recommend?