Nissan Micra - High Fuel Consumption

[Tailgunner]

Hi, I have a 1988 Nissan Micra that uses too much fuel. It is returning about 33mpg at present. In my owners manual it states that for urban driving it should return around 45mpg and at constant speed driving at 75mph around 55mpg. The engine seems to be running fine. I have fitted a new air filter, had an oil change and a new oil filter and replaced the plugs. I do not believe the distributor is dirty or the timing is off because as I say, it runs fine. Was wondering if any of you out there could help me as it is costing me a lot to run at the moment. Thanks

Toby

[spithray]

Maybe you could try taking it for a tune.  I had an old Fiesta Si that was running like a dog.  Turns out the injectors were fouled up.  Tune cost about �25 and the supplement about �5.  You could cut out the middle man I suppose.  I used an SDP injector cleaner, comes in a black bottle from pretty much any car parts shop.

[Tailgunner]

Hi, thanks for your reply. I have already tried an injector cleaner and obviosuly it didn;t work. The fact is I do not have much money to spare. �25 is steep for me lol (us students again lol). Thanks again

Toby

[tubeway]

Its old - like people things wear out and get less efficient as they get older - your car is the same.

[Tailgunner]

It has been well looked after and is in good condition. I cannot see how it is worn out as it passed an MOT with colours. Many other Micras that I know of are much more efficient than mine and some are older than mine. Even so if it is old and worn out, 33mpg is ridiculous, surely it wouldn;t be as bad as that.

Toby

[Kev_UK]

Firstly, NEVER believe what the manufatures say. I had a brand new Ford Sierra 1.8L estate once andI was getting only 25mpg, even the garage that tested it ony got 27mpg.
It depends on how many gear changes, inclines, start & stop conditions, how much accelatation & braking you do.
33 mpg is good for any car, I've had little 1.0 Litre cars so I know. I have 3 cars now, all yank cars.. my daily driver is a 5 litre V8 and I can get 26mpg on a run (better than range rovers, etc). I use more fuel when using the loud pedal more, but hey, you don't buy a muscle car to potter around at 20 - 30mph all the time LOL.
Check the air filter, it may be dirty.. I changed mine every 6 - 12 months as they do affect performance and fuel consumption a lot.

[Kev_UK]

BTW, fuel consumption or engine performance is NOT part of the MOT test.. I could take my V8 in for an MOT with it running on 5 or 6 cylinders.. and as long as it passes the emmisions test it will be given an MOT, regardless of what mpg or performance I get.

[Gef]

Are your tyre pressures correct?

[Tailgunner]

Yes the tyre pressures are correct at 27psi. I honestly cannot see why it is using so much fuel that clearly for a 988cc car it should be .