Help mpg worse than I thought , I think !!

Thought mpg was pretty awful (even for series 3 ) put £20 in there and get 45 miles out of it . Decided to use sat nav to confirm mileage however now realise rolling total after dial reset seems to be in kilomteres !! Is this right ?? That means that ive actually got 45 km out of £20 which is worse , isn't it ?, presumably that also mean that overall mileage is wrong , don't get it , why would "mileage" be in km , and it definitely is as reading on Sat nav km was exactly same as dash


Any advise would be appreciated

Thanks

neilcmusic said:

Thought mpg was pretty awful (even for series 3 ) put £20 in there and get 45 miles out of it . Decided to use sat nav to confirm mileage however now realise rolling total after dial reset seems to be in kilomteres !! Is this right ?? That means that ive actually got 45 km out of £20 which is worse , isn't it ?, presumably that also mean that overall mileage is wrong , don't get it , why would "mileage" be in km , and it definitely is as reading on Sat nav km was exactly same as dash


Any advise would be appreciated

Thanks

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Telling us what kind of engine it is might help!
4cyl petrol, I would expect between 15-20 to the gallon. 4cyl diesel up to about 28-30 to the gallon.
Fuel mileage of any vehicle is massively influenced by driver technique. Are you driving it like a landrover, or trying to keep up with the cars?

Sorry, its petrol 2.25 4cyl , no overdrive, I use it for everyday vehicle but only live 3 miles from work so I only drive about 6 miles a day and probably never go over 40mph with occasional shop runs , it leaks like the titanic and costs me a packet in fuel but its great, thought I was getting about 15mpg out of it but have worked that out on the gauge thinking it was measuring miles not km/h , clock reads 78000 genuine mileage , I have all the mot certificates from new !! But am assuming that's km now and not miles also

3 mile journeys will kill the fuel economy of any vehicle. Fill up check if the fuel tank is leaking, go for a nice 100 mile gentle drive and check again.
I assume it is serviced and set up correctly ? The worse I ever got from a six pot was in double figures (Just)
Over the years I have had 2.25 petrol 15 to 20 MPG
2.6 six pot 10 to 15 MPG
2.25 diesel 25 to 30 MPG

neilcmusic said:

Sorry, its petrol 2.25 4cyl , no overdrive, I use it for everyday vehicle but only live 3 miles from work so I only drive about 6 miles a day and probably never go over 40mph with occasional shop runs , it leaks like the titanic and costs me a packet in fuel but its great, thought I was getting about 15mpg out of it but have worked that out on the gauge thinking it was measuring miles not km/h , clock reads 78000 genuine mileage , I have all the mot certificates from new !! But am assuming that's km now and not miles also

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Short journeys are very expensive on fuel. You will have the choke out a lot, and oils will never heat up and thin out. Takes a lot of fuel to stir the cold oils in diffs and gearboxes.
When you say leaks like Titanic, hoping that is water leaking in? If you mean petrol leak, get it sorted, very dangerous!
I suggest you try and take the vehicle for some longer runs, will do it a lot of good, in many ways.
Also, make a good calculation of fuel mileage! Fill tank to brim, so you can actually se the fuel at the top of the neck. Then drive normally until the tank is about on third full. Then refill, exactly same as before, right up to brim.
Record the mileages start and finish from odometer, fuel receipt will have exact amount used. Basic maths! Accurate-ish fuel figs!

Carburettor can make a difference as well in some cases.
Do you know if it's a webber or a zenith/zenith copy.
I had a zenith copy on my ffr 109 for a year and got awful mpg, couldn't give you figures as never worked it out but it would cost me about 30 quid to do 60 miles.
Now with a webber it costs me about 25 quid to do 90 miles depending in my driving of course and bear in mind my ffr is heavier, has more load on the engine and had the tilt which causes alot of drag so YMMV.

MigGames said:

Carburettor can make a difference as well in some cases.
Do you know if it's a webber or a zenith/zenith copy.
I had a zenith copy on my ffr 109 for a year and got awful mpg, couldn't give you figures as never worked it out but it would cost me about 30 quid to do 60 miles.
Now with a webber it costs me about 25 quid to do 90 miles depending in my driving of course and bear in mind my ffr is heavier, has more load on the engine and had the tilt which causes alot of drag so YMMV.

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Yes, very worn or badly adjusted carb wont help either.

took a look today at mixture screw was about 10 turns out so have adjusted it , now only approx 2 turns out so hoping this helps , why is odometer in km/h and speedo mph??

neilcmusic said:

took a look today at mixture screw was about 10 turns out so have adjusted it , now only approx 2 turns out so hoping this helps , why is odometer in km/h and speedo mph??

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cant help with why your speedo is like that , but taking off the mechanical cooling fan will get the engine up to temp faster in winter time, 3 mile trip would hardly be enough to heat it for optimal fuel burn .and your mixture screw was way out too

If your engine has only done 78k miles, fill the tank and go for a run on the nearest motorway ... and hammer it!!
That should lubricate everything asnd clean all the crap out of the systems.
6 miles a day isn't doing her any favours at all, and will wear her out in next to no time!
A 2 1/4 in a Series III should give a return of 25+mpg if everything is set up and properly tuned for economy!
If you are tuning her yourself, don't go by the book settings ... it's all done 'by the ear'

Oldseadog said:

If your engine has only done 78k miles, fill the tank and go for a run on the nearest motorway ... and hammer it!!
That should lubricate everything asnd clean all the crap out of the systems.
6 miles a day isn't doing her any favours at all, and will wear her out in next to no time!
A 2 1/4 in a Series III should give a return of 25+mpg if everything is set up and properly tuned for economy!
If you are tuning her yourself, don't go by the book settings ... it's all done 'by the ear'

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Agree with the long run, will also decoke it a bit, and possibly deglaze the bores a bit.
25 mpg seems a bit optimistic for 2 1/4 petrol, though?

The front face of the speedo should be marked KPH or MPH.

25mpg, is that with the body off, downhill with wind behind you?

series2steve said:

25mpg, is that with the body off, downhill with wind behind you?

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No, that's on flat ground with a very light foot. The type of tire's fitted also makes a difference.chunky types are worse and having the right size for what you are doing helps.Got the best mileage from my old 2a when fitted with 7.50 size lorry tires.

tottot said:

No, that's on flat ground with a very light foot. The type of tire's fitted also makes a difference.chunky types are worse and having the right size for what you are doing helps.Got the best mileage from my old 2a when fitted with 7.50 size lorry tires.

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Agree completely about the tyres. IIRC 88" had 6.00x16 crossply and 109" had 7.50x16 crossply as standard for most of their history. So it would stand to reason a 265/85 radial will soak up a bit more power and fuel.