Please dont shoot me just yet.......

[Ghost_2008]

...... I know it's something to be expected but still I need to ask for my own peace of mind........

Basically I have owned my VR4 Legnum for two years, when I first owned her she would regularly return mpg in the region of 20 - 25 mpg......... granted this was mainly up and down the A13, A12 and A406 at speeds of 60mph combined with town driving....... now I'm not doing the A road driving as I work about 4 miles from where I live......... My MPG has now dropped to 13mpg........... is this normal?

The car runs fine, pulls fine nothing to suggest an issue except for the poor mpg......... I dont feel that I have a particulaly heavy foot however I do get the AYC to illuminate two bars atleast once or twice a day..... could it be that I have grown a custom to the power and speed???

I am just a little concerned that I used to regularly get 150 miles to approx 35 gallons, where I am now only getting 100 miles per 35 gallon.......

Is there any known issues that could cause this sort of differnce, also I changed Tyre's, I am now using Toyo runflats, could these effect the mpg????

[miller]

nah, im the same. Rarely gets long run outs and im lucky to get over 150miles to the tank.

Its the short hops that do it to the fuel consumption

[WildCards]

16-20mpg are normal figures for an auto Legnum in my experience. 13 maybe a bit low, but try driving economically for a tank and see if it makes a difference.

[foxdie]

Same here, VR-4s weren't meant for city driving :/

[WildCards]

If it helps, I can only get 18-20 out of the manual fwd Saab with city driving.

[TAR]

I too make quite a few short town journeys and this really drinks the fuel. I get much better economy when giving it some on a longer run.

The answer is to leave earlier for work and enjoy a good drive before turning up for another boring day in the office!

:happy:

[foxdie]

The answer is to leave earlier for work and enjoy a good drive before turning up for another boring day in the office!

That's what I do on the way to work (and as such, get to work for 7:15am), but going home in rush hour, forget it lol.

[Wobble]

am getting 17 -19 mpg when driving normally. mostly town diving too . where abouts in essex are you just out of interest.

[Ghost_2008]

Cheers Guys..... I feel a little more re-assured now, I love to push it so running a whole tank in "Economy" mode will be a challenge.......


am getting 17 -19 mpg when driving normally. mostly town diving too . where abouts in essex are you just out of interest.

I grew up in Hornchurch near Romford but I now live in Chingford...... Chingford used to be Essex but my address reads London.....

Where abouts in Colchester are you? I ahve friends that live in Silverend....

[AlanDITD]

Could be the lambda sensor on its way out...

But town driving is shocking my i swear my fuel gauge used to go down sitting in traffic

[scc]

Isn't driving a VR$ like driving a non-turboed V6 around town which can achieve much better MPG regardless?

Cheers,
scc

[Turbo_Steve]

scc - No. It's got an autobox which loses 7% extra power everytime you pull away from a standstill, and it's got 4WD which takes a lot more effort to turn.

Ghost,

It may be worth doing a long drive and seeing how the mpg holds up - As Alan says, it's possible your lambda sensor is going/gone. It's a cheap fix and makes a huge difference to the economy.

It's also colder at the moment, which means the car uses stupid amounts of fuel before it gets up to temperature. That white misty stuff behind the car when you reverse it out of the drive, and up to the first roundabout.....that's pretty much pure fuel vapour on a VR4!

[davcom1]

I am just a little concerned that I used to regularly get 150 miles to approx 35 gallons, where I am now only getting 100 miles per 35 gallon.......


Surely not!?

That's working out at around 4.25mpg and 2.9mpg :oops:

But yeah, mine is low mileage and only delivers low teens.

[Johnny_Cashed]

I do pretty much the same miles to and from work in my n/a Galant and get around 27mpg.

[Beastlee]

Mine is currently on 17.8mpg average since before the trip to the Ring. I do about 2 miles a day in it and I give it plenty of loud nearly all the time. I recommend an LC-1 to replace the OEM lambda as it seems to improve things no end.

I'm guessing it's 35 litres. In which case that's about what I expect.

[Ghost_2008]

Surely not!?

That's working out at around 4.25mpg and 2.9mpg :oops:

But yeah, mine is low mileage and only delivers low teens.

My bad...... I did indeed mean 35 liters not 35 gallons..........

OK so the Lambda measures O2 and adjusts fueling accordingly........ if it has gone, whats the options and benefits I have....... I'm not really intending to extensively modify but I do intend on keeping the car for as long as posssible.....

[kiteman]

If its any consolation to you guys, my legnum is over fuelling like crazy.
My last track day in early december I got 122 km for €82 of fuel, I had a full tank and full jerry can arriving at the track.
When converted to MPG, I calculate I was getting 2.75 miles per gallon.

[davcom1]

Ghost - sorry, was just being a smart arse!

Kites - that's SCARY!! /Fever

[AlanDITD]

Mine is currently on 17.8mpg average since before the trip to the Ring. I do about 2 miles a day in it and I give it plenty of loud nearly all the time. I recommend an LC-1 to replace the OEM lambda as it seems to improve things no end.

I'm guessing it's 35 litres. In which case that's about what I expect.

How does fitting a wideband lambda improve things?

i was under the impression that it just linked back into the ECU as a narrow band like the standard one and runs from 0-1v. and to your gauge as a wideband

Also from what i read on the LC1 there forever requiring calibration causing even worse fueling.

More interested in how its helped the fuel economy though :)

[Nutter_John]

beacuse you can fool the ecu with the LC1 to think it is running 14.7 when in fact your running 15.7 , this in turn means you are running far leaner when on closed loop , thus using less fuel

[bradc]

Kiteman, around tracks I tend to use 40-43L/100km

[Beastlee]

beacuse you can fool the ecu with the LC1 to think it is running 14.7 when in fact your running 15.7 , this in turn means you are running far leaner when on closed loop , thus using less fuel

What he said, and I'm running mine like that now. As mentioned I get 17mpg average with me hooning around all the time and it passed the MOT with flying colours.

[SGHOM]

My 2 ltr saaaab is currently doing 16.2 mpg :rolleyes3

[WildCards]

That's horrific D, obviously making full use of the loud pedal?

[hardarse]

glad to know its not just me with this problem all i ever do is 10 minute drives now and i struggle to get good economy

[confusis]

fuel/air filters? maybe time for an oil+fluid change?

i got an extra 10 mpg back after changing the oil, gbox oil, and air filters in my 1.8l primera!

[psbarham]

beacuse you can fool the ecu with the LC1 to think it is running 14.7 when in fact your running 15.7 , this in turn means you are running far leaner when on closed loop , thus using less fuel

so does the gauge still show the correct afr or the corrected afr? if its the correct afr then /Hmmm

[ritch_w]

4 mile commute in this weather - the engine is never going to get near optimum temperature. Most likely the whatever the EFi equivalent of auto choke is, is firing more petrol into the engine to account for the engine being cold - which is probably for majority of your journey hence shocking mpg.

Should be better in summer, but short journeys in a twin turbo v6 are never going to be mpg friendly

[Nutter_John]

so does the gauge still show the correct afr or the corrected afr? if its the correct afr then /Hmmm

yeah Paul the gauge will show the actual AFR , when you configure the LM1/LC1 to output a value on one of the outputs you set it to be out by 0.5 / 1 afr , this is what the ecu sees and adjusts the fuel . But it does not alter the value on screen as that is the true none modified out of the exhasut flow reading

hope that helps

[Ghost_2008]

fuel/air filters? maybe time for an oil+fluid change?

I got an extra 10 mpg back after changing the oil, gbox oil, and air filters in my 1.8l primera!

All the fluids were changed for Amsoil less than 4000 miles ago, except for the engine oil which i changed just before Christmas, so I should have plenty of life left in the fluids.....

I'll check the Air filter and see what I see............ but I checked that a few months back and it seemed fine.....

[amsoil]

Ow-30 oil will minimise the warm up time and maximise the MPG in addition to this try and injector cleaner, not expensive and all the stats say very cost effective. I use one every 6months to maximise things.

[Ghost_2008]

Ow-30 oil will minimise the warm up time and maximise the MPG in addition to this try and injector cleaner, not expensive and all the stats say very cost effective. I use one every 6months to maximise things.

Year I'm running that spec oil and I use redex fairly regular, but I'll check the oil and filter tomorrow or Sunday. Going to go for a little drive tomorrow to see if I can get the mpg up....