Poor Economy!

reynolds_p1 · Post by **reynolds_p1** » Tue Nov 22, 2005 2:29 pm

At present i'm getting a little over 250 miles for a full tank (60L!!!) in my turbo. This is poor! (no sh*t!)

any ideas that i could try without replacing stuff? (as im skint!)

(ive serviced it recently with new oil and filter, plugs and leads and i use redex injector cleaner when i fill up -which has helped lift the economy slightly)

It could well be the lambda sensor but thought id just check first to see if there are any suggestions that dont involve new parts!

Cheers!

martyc · Post by **martyc** » Tue Nov 22, 2005 3:18 pm

has it always been that bad? how'd ya drive it? is it still driving ok?

reynolds_p1 · Post by **reynolds_p1** » Tue Nov 22, 2005 3:41 pm

yeah it drives ok, it has the power it should do. i tend to drive pretty uneconomically but not that bad to get these kind of fuel figures! Yes it has always been like it (ive had it about 2-3mths)

It tends to get quite hot quite quickly engine wise (oil temp) will be upto 90degC quite quick even just about town and normal driving will have oil temp of about 93-100deg C and if doing say 110-120mph on, ahem, private driveway, it will be around 105+ this seems a bit high to me, i dont know if its related to the economy.

the oil is newish (serviced see above) and is fully synth 10w-40 and the oil pressure is good though.

Engine temp sensor a possibility perhaps? (car thinks its cold all the time-pumping more fuel in) doesnt explain high oil temp tho (or maybe it does...???)

martyc · Post by **martyc** » Tue Nov 22, 2005 4:20 pm

ya not got a fuel leak have ya?! oil gets a lot hotter than water because this is the stuff that comes into contact with hottter parts (pistons for example) so i don't really think this is an issue, infact cold oil is more detrimental!! it could well be a case of overfuelling due to incorrect sensor readings, remove ya spark plugs and check the colour of them, this should give a rough guide to the fuelling, things such as tyre pressures, even lightly binding brakes or drag created from another area can cause this so might be worth investigating too.

martyc · Post by **martyc** » Tue Nov 22, 2005 4:22 pm

even a clogged air filter!!!

Brasco · Post by **Brasco** » Tue Nov 22, 2005 4:32 pm

What are the revs at idle?

stu chacks · Post by **stu chacks** » Tue Nov 22, 2005 9:19 pm

Also if your using your trip computer to measure average fuel economy and not actually doing any decent constant driving, your reading will always be around 15-20mpg tops.

Mine around town is as above also, but when I do the work run which is 20miles mostly duelcarriageway it picks it up to 30mpg average door to door.

Have you taken her out and done a good steady (70mph) run on a decent road and seen what you got?

Stu.

Big Brother · Post by **Big Brother** » Tue Nov 22, 2005 9:23 pm

I had a problem with the Celeb using way to much fuel, after having it tuned and gas treatment the fuel consumption improved greatly, as did the performance

Ad

Bramdeman · Post by **Bramdeman** » Tue Nov 22, 2005 9:26 pm

I once had the same problem, car running fine but using to much fuel, cleaned the injecters and fuel consumption dropped by about a third

BlueCruiser · Post by **BlueCruiser** » Tue Nov 22, 2005 11:17 pm

While this is on discussion, may I just ask a couple of things which are also related to fuel economy and range...?

1. The very top bar of the fuel gauge (digital one) is always missing even it is fully tanked up..Is it normal? Or does my fuel gauge just missing out that green bar by faulty sensor / IC electrics...etc?

2. Well, doesn't matter, I got used to that now...But according to the IC range data, when it's newly refuelled it often shows between 265miles (been on mostly urban driving before tanked up) up to the very best I had is 460miles (taken from motorway crusing)...Average is about 360miles...So how does that sound? (I know even though I shouldn't just rely on the IC but to calculate that myself everytime after I refuelled, but as a source of information it might still help!)

by the way mine is a 94 ES with a 60L tank, I presume...

Many thanks! (as you can tell, I'm very new..glad to have joined the club though, please bear my ignorance!

reynolds_p1 · Post by **reynolds_p1** » Wed Nov 23, 2005 11:29 am

Brasco - idle is usually around 600rpm when just started then around 1000/1100 when up to temp (which is a bit too high - but if i adjust it when its warm then there arnt enough revs when its cold...)

if i take it out and do a steady 70 (not that this happens a lot!) it is better as you would expect, but not by much. coming back from glasgow t'other weekend from glasgow to i did a steady 80mph from glasgow to the lake district (about 135ish miles) and it didnt really make a difference (this is going on working out the consumption too, not on the IC readings)

been using injector cleaner as i said for a while now, not made that much of a difference.

The oil is supposed to be hot yes, i know but its a bit too hot (not dangerously or anything -warning light comes on at 140degC i think) but still a little over what it should be.

I think i'll change the air filter and lambda sensor (when i can afford to) see if that cures it!

ICFM · Post by **ICFM** » Wed Nov 23, 2005 2:36 pm

Pretty obvious but often neglected - check your tyre pressures. Cold weather = low pressure = bigger footprint = more fuel.

Iain

Brasco · Post by **Brasco** » Wed Nov 23, 2005 5:40 pm

the engine sounds like it's running fine to me. You don't live near a lot of steep mountains do you?

guitarcarfanatic · Post by **guitarcarfanatic** » Wed Nov 23, 2005 6:07 pm

Brasco wrote:the engine sounds like it's running fine to me. You don't live near a lot of steep mountains do you?

Or a bunch of petrol syphoning pikeys?

ozturbo · Post by **ozturbo** » Thu Nov 24, 2005 12:28 pm

I have driven my turbo here in Italy and France, Spain and Austria about 22,000 miles and have checked the economy many times by calculating the distance and quantity of fuel according to the petrol pump when filling up and I always get at least 440 miles on a tank (60 litres). It gets 29 mpg around the town and the local area which is very hilly and on the open road gets 35 -37 mpg at around 80 mph. In fact its most economical speed is 80 mph. My fuel guage doesn't seem to show the top bar either.The info centre is pretty close when telling you how far you can go on the current amount of fuel.

TLindley · Post by **TLindley** » Thu Nov 24, 2005 5:14 pm

I have noticed tyre pressure makes alot of difference to mpg if you are doing alot of miles. I make sure mine are always at 32psi.
Whats the recommended, or the highest you think would be safe? I just keep it at 32 as this is what all my previous cars have had, and they have equivalent size tyres.

JayTee · Post by **JayTee** » Thu Nov 24, 2005 6:23 pm

I keep mine at about 34psi

ICFM · Post by **ICFM** » Fri Nov 25, 2005 12:54 pm

Yep 32 - 34 psi will do it.

Ben Harris · Post by **Ben Harris** » Fri Nov 25, 2005 1:15 pm

The sticker on the inside edge of the passenger door on my 480 says 30psi for the front, and 28-30psi for the rear, depending on whether it's carrying passengers.

I tend to try and keep them at 30psi all round.

Ben.

ozturbo · Post by **ozturbo** » Fri Nov 25, 2005 1:18 pm

I keep mine at 30psi all round too.