AllyJ

Normally I get the usual cr$ppy 230 miles to a tank in my 05 STI urban mileage, but last 2 tanks Iv only just scraped over the 200miles?? Now I am presuming this may be due to the excessive chilly weather and heavier boost, running richer? Car only 6 weeks ago had its 30k service and its in mint condition so cant think its anything mechanical, anyone else experiencing this? Oh and before any smart alec says depends how much they 'rag' it, I dont, and normally get 230 odd urban miles without redlining it thank you

Tidgy

yep be the cold weather, try it on a DRY night and stright road, will feel like its pulling stronger than ever.

Dark Blue Mark

It will be performing better due to denser air, and therefore using more fuel, but it should be more efficient while doing so - ie your mpg will be less but its actually giving more power from the fuel its using.

If its significantly worse and continues to be, and you have bad idle, your lambda may be fooked.

evander

iTrader: (1)

Yeh I agree with the others, cold weather, I also have noticed less mpg.

34srm

is it less mpg oris it over £1 a litre thats doing it, its currently £1.06 near me so in last month or so gon up 50p a gallon at least

rikroe666

yeh me too i get about 200 miles out of my 02 sti.

B0DSKI

iTrader: (17)

Same here just scarpped over the 200

danfranklin1

Get too depressed if I were to sit down and do the figures... needless to say, at least £70 a week of my hard-earned is going straight to Shell (actually, mostly to the government..) but does seem a bit more thirsty in the cold.

Klaatu

I'd say that would be about normal for a vehicle like an Impreza. I get about the same from my 2003 RX auto.

fattb

iTrader: (1)

The undiscovered country

bushiwarrior

correct

AllyJ

thanks guys nice to know fellow owners getting the same. I thought it was the reason but you never know. Yes car pulls like an absolute train aswell its def putting out more power in the denser air no doubt, and of course as we all know 109 a litre doesnt help

jasonius

iTrader: (1)

What I don't understand is (and I'm assuming the STI has the same size tank as the WRX) I can easily get 250 to a tankful and nearer 300 without really trying. Also, whilst it does feel a bit stronger in the cold, I don't notice a drop in economy (there's a word you shouldn't use for an Impreza, lol..!).

And before anyone says mines only a WRX and we're talking about STI's, it's pushing 350 and will embarras most >400bhp STI's..!

The only thing I can think of is you guys drive 10/10th all of the time..! Or could it be the 6sp ratios..?

McWRX

Could your Mods be helping with economy? Mines an 02STI and struggling to get over the 200 mark with the cold weather. Was 240-250 a couple of months ago.

Does a remap help with MPG!?

AllyJ

it did on mine well not much vs the ppp i used to have. Mine would do about 200 in summer on the ppp, then it rose to about 220-230 on tsl333map..driving on motorways itll hit 300 if i do 70 the whole time and dont slow/ get stuck in traffic etc.

It has dropped basically down to 200 in the winter so lost about 1-2mpg i guess from the summer norms.

beef-on-the-bone

iTrader: (5)

it's a good day when i get over 200 from a tank!!!! lol

postie90

i get roughly 200-220 in my wrx stadard...

The rookie

iTrader: (1)

Cold weather = cold start = more fuel needed
Cold weather = heater on and slower warm up = more fuel used for temperature compensation
Cold Weather = thicker oil at start and more drag
Cold weather = slower in getting oil to temp and more drag
Cold weather = heated rear windows and more alterantor load
Cold weather = Winter = darker = running with lights on which costs you about 3%, or about 5% if you use front fogs as well
Cold weather = denser intake air at WOT so more fuel used (even if you do accelerate quicker)
Cold intake air (on a cruise) = throttle shut more for the same mass air flow = more pumping losses dragging air past the throttle.
Cold Weather = cold PAS fluid so more drag
Cold weather = thermostat open less so more water pump load

I think you get the drift - winter is bad for your FE (But great for power!)

Simon

Dark Blue Mark

Thanks!

mgcvk

I have had over 400 miles to a tank in mine when decatted and remapped (yes I know its hard to believe) and could easily get 350 to a tank with mixed driving. It did start to drop a little once I got over around 50k though. Now with the sti injectors and vf35 I am very very lucky to get 250 miles even with poncey driving but I suppose thats to be expected. I should probably get the sensors checked out as well though.

ex-webby

I am still shocked that many of you get these sorts of mileages out of a Newage. I get between 200-230miles from a tank...... on a Spec C (50ltr tank so smaller) running over 500bhp on a 2.5l engine. Mine travels far from sedately.

Seriously though.... it does make you think.

Regards,
Shaun

Hoppy

Excellent reply And if you do a lot of short journeys, like under 5 miles, the car will never get properly warm and your mpg will be in the teens. Not good for the motor either, so give it a good run a couple of times a week, all electrics off.

Richard.

mgcvk

Thats very good going on a 50 litre tank with that spec, bearing in mind most of us with more standard newages have 60 litre tanks. I reckon these engines have a peak efficiency between 20-30k miles when they are run in and functioning at their best. I would imagine your motor must also get extremely well looked after though?

The rookie

iTrader: (1)

Big turbo's are better for mpg when sruising as they have a lot lower back pressure due to the larger turbine housing.

Simon

ex-webby

If that is so how come my previous 2ltr set-up with a puny twin scroll turbo produced the same mpg (when it was circa 370-380bhp)?

Must be all in the mapping!

The rookie

iTrader: (1)

Circa 370/380 is a larger turbo (you won't get that out of a stock TD04 will you?) in terms of turbine size!

Scotsman

iTrader: (3)

I've noticed a slight drop in fuel economy as well. Still get 300 plus miles on a full tank though and that's a mixture of driving (motorway/town) in my 300bhp bugeye.

Norman Dog

iTrader: (1)

Just filled mine up and I'm getting a remarkable 18.43 MPG

All urban driving, my firm's relocating in January and will be mostly motorway driving to work, hope this helps a bit.

Does a remap make any difference to fuel economy?

Flaps

iTrader: (1)

I normally get about 280 miles for the full tank but this time only got 220 before the light came on.