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[foyaz_95]

Hi guys,
Just recently bought a forfour and I've noticed I'm having to spend quite a lot on petrol. This is due to the fuel gauge which I think is inaccurate. Anyway, I wanted to ask how much mpg I should expect on London roads. Right now £10 petrol gives me like 50 miles and the fuel gauge shows 1.0l left.
I wanted to know ask whether this sounds right or should I be expecting more?
Thanks.

[Problemchild]

Seems a bit low but say £10 gets you 7 ltrs of petrol then 50 miles on 7 litres is about 33mpg which isn't too bad around town.

JJ

[CrazyG]

MPG will depend on road conditions such as traffic, number of stop starts
and also on how you drive it.
If you try to pull any gear with too low a revs of the engine then you will
be 'dumping' loads of fuel in. The 1.1 thrives on being revv'd...as mr singh
will tell you.  Read the road, keep it smooth, brake as little as posible..
advice any good driver will give you.
Drive like a 'nancy' and the fuel will not last as long. Ditto if you drive
too madly.
In truth, driving is a art.

Oh, and if you still only manage to get 33mpg (as per JJ's calculus)
then imagine what those 2litre Mondeo's etc are returning their owners !
Think just over 20 and you won't be far wrong.

[mr singh]

stop being cheap and tank it fully! putting a tenner in wont be doing the fuel sender. you are more likely to burn out the fuel pump as the fuel is used as a sort of cooling effect on the pump. i found that out when the 2.0 V6 X-Type fuel senders used to burn out and Jaguar said to keep then tanked up. once a new sender unit was fitted and the tank was brimmed the fault never re-occurred.

i regularly tank my 1.1 and gives me over 420 miles to a tank. that said my driving has changed since i bought it. when i bought it i was using it mainly round town and since 2012 my mileage has gone up from around 6-7000 miles a year to roughly 20,000 miles a year with the commute to work in York.

my commute to work can be anything from 25-35 miles depending on route taken and i can get from Leeds to York without using the brakes, or using the brakes very little.

also switch your engine off when your not moving, an idling engine will waste fuel.

[Problemchild]

also switch your engine off when your not moving, an idling engine will waste fuel.

ONLY if its for longer than a certain amount of time It uses a "lump" of fue to get the car started and it also impacts on the battery as starting a car takes quite a bit of power out of the battery.

also, don't coast with the clutch in. always leave the engine engaged as the ECU will only add minimal fuel compared to tickover.

BUT your best way is to plan ahead, try not to come to a total stop etc, minimal throttle travel using the gears (i.e. 5th in a 30 zone is quite possibly not as efficient as 3rd if there are variations in incline etc)

but as mr singh says, fill up and then drive till the warning comes on and then fill up again. compare miles vs fuel put in and work it out.

JJ

[mozilla]

I've heard of a 1 min rule for turning engine off or not when at the lights. Not sure though as its a feature of newer cars now

Coasting 'in gear' will virtually shut off fuel supply and let the wheels turn the engine however the transmission has quite a bit of parasitic loss and the car will travel further when in neutral. Not sure which ways more fuel efficient

[djames108]

If you coast in a higher gear it should be  more efficient as the tick over in say 5th will keep you going for longer than say 2nd or 3rd (Depending on incline etc)

As an example the road to my house is roughly 1/4 of a mile down hill, you can go in 3rd and use very slight throttle or in 4th the tick over will allow you to coast it to my front door as it levels out about 100 yards from my house.

Plus you are more in control of the vehicle when in gear which is why i never coast with clutch down or in neutral.

[CrazyG]

It is also illegal to coast.
as aleready stated, if you leave it in 5th rather than 3rd going
downhill the engine will use less fuel.  Just plan your driving
and think ahead all the time. Smoothness can save you loads.

[FireFlower]

I've heard of a 1 min rule for turning engine off or not when at the lights. Not sure though as its a feature of newer cars now

Coasting 'in gear' will virtually shut off fuel supply and let the wheels turn the engine however the transmission has quite a bit of parasitic loss and the car will travel further when in neutral. Not sure which ways more fuel efficient

It is if it seems you will be longer than 3 minutes in traffic jam or something. Newer cars do that automatically always when you stop at reds and turn back on when you press gas. Pretty useless feature in Finland because lights always switch in 1 minute

[Fox]

Keep the tva clean and check tyre pressures regularly.
IME the 1.1 loves a nice clean tva and you'll really notice the improvement fuelwise.
Use premium fuel or drop a bit of redex in now and again.

I can really tell when these things have not been done.

[FireFlower]

Old threat but for others who are wondering is that 50mpg even possible...

Currently 300km driven (home - work - home x 3). about 50% 'highway', 50% city traffic speeds

Mine torque is "calibrated" so ECU doesn't lie. Calibration == Drive until you have 5l warning popping up, go refill with 5-10l. Reset odometer and drive until you get it again and have torque running with default settings. When you have that 5l warning stop and look what your odometer is telling you and calculate correct consumption value. Then adjust the setting so long until you get correct fuel consumption showing on torque. Mine is 1.09

[Brabs]

As most people know you can 'bin' whatever mpg figures manufactures give... although that is likely to change soon!
As has been said, so much depends on the circumstances of your journey. Not in any particular order...

The ambient temperature
How quickly the engine warms up
The length and type of journey i.e stop start or continuous
Appropriate gear usage for road conditions
The health/state of tune of the engine... when was it last serviced
Tyre pressures
The type of tyres on the car
The weight of the car plus contents... clear out unnecessary crap
The number of occupants in the car

And possibly last of all... your driving style.

[FireFlower]

So you think I cannot keep up that 50mpg?



Here is the graph and little bit explains what did I do... It is all about drive style and of course your engine has been maintained.
Currently thing that is slowing me a bit is back wheel bearing which is pretty noisy already. Going to change that and rear brake disks when parts arrive from Germany.

[FireFlower]

746km driven and 42 litres fuel consumed.

Torque shows 5.6l/100km average and 50.2 MPG

Calculated: 50.17 MPG and 5.63l/100km