the only trouble you may face is that you're not being overly kind on the DMF at that, as 1,500 ish RPM is where you're going to see peak torque from the motor, so if you're giving it full throttle at low revs it'll take its toll which will wear on the DMF over time. if you're only accelerating gently then you're not going to come to much harm.

on later models (159, Brera, etc) the DPF won't thank you for running it at low revs constantly, you're better off to get them hot and blow them through with some revs, but these cars only have cats which don't cause much problem either.

EGR will get a build up over time thanks to the oil recirc and soot in the gas recirc but that'll happen regardless and is good maintenance to keep it clean, just clean with service should suffice.

your turbo won't suffer really - you should think about your turbo as you near the end of your journey, as you want to take is easy, like no high revs / full throttle, to allow the turbo to cool down at the end of the trip, this will help give the bearings a longer life.

everything else should be just about fine really and won't suffer anything beyond normal wear / tear I would suspect.

 

thank you! :thumbs:
it's a good advice and while I am not stepping on a pedal while in low revs (it's doesn't feel right in the most of the cars - they vibrate not in a nice way), it's worth knowing about peak torque and DMF anyway.

since it's a first car for me with turbo, I am a bit 'preoccupied' I think.
I read somewhere that the working range for it starts at 1900 revs. Would it be correct? and would it mean that while going with lower revs turbo is not under stress and as result its bearings are not heated/stressed?

 

The only downsides I can think of are tedious journeys, that take 20% longer - being overtaken by vicars on their way back from church - getting beeped by the over 80's for hogging the slow lane - falling asleep at the wheel - and most importantly, your potential love life, if you are thinking of telling anyone else in the outside world your findings... I beg of you, stop this behavior before it is too late... bury that right foot, else it will be 'extreme coupon-ing' by the end of the week...

 

:tut: not sure why would they be longer? as I mentioned (from the experience) actual speed didn't suffer.
First - because at the time of my journey the speed of the flow is about 50mph at the best on M3. Even with less dense flow in the opposite direction it took the same time as before when I was changing gears differently.
Second - I didn't quote speed, but I did quote gears and revs and it's not that difficult to make a conclusion on the speed
Third - I didn't drive at let say 90mph on the motorway before, so not going to start now.

If there is a difference - it is when I take off from the traffic light and when I accelerate to join the motorway.

But! I do like the spirit of you post :lol:

 

well, time to share some experience

first long range measurement gave me following:
trip computer showed 59.9mpg over 620 miles (motorways about 70-80% of it).
pumped 61.54 litres, at the same pump and doing the same - first cut off.
Real world mpg - 45.86mpg.

So I thought - I can do better (slower?)
not such long trip, only 123.1 miles. and this includes 8 miles of Italian tuning - up to 4,500 rpm and maximum third gear. It was late in the evening so I didn't see all the smoke :lol: well, not until someone caught up with me and I didn't really see the headlight in the mirror - just a halo of light :lol:

anyway, second trip, 123.1 miles, 11.24 litres. Computer showed 64.3mpg, real life - 49.79mpg and one mile cost me 12.41p per mile.

 

i would say that its fine and quite sensible to do what you're doing - just occasionally give it a proper blast/thrash, clear all the cr@p out

 

The most mileage I ever got from a tank-full on my 16v JTD was 690, but that was trying to conserve fuel to reach a service station and involved tail-gating trucks. Typically I would get 620 miles; in the 20v I did get 540 miles once but typically I only get around 500, but I do seem to get more using "super" diesel. Just find it so difficult to drive the 20v economically

 

yep, 620-630 is a standard figure so far.

690... that's probably not going to happen, I just can't help but push the pedal especially when joining the motorway and a slip road is up to the hill.

got 2stroke oil in Sainsbury's for 2.99 (500ml) and started using it as an additive.

EDIT: corrected thread name

 

Wow, I'm quite shocked at these numbers.

I did some calculating and I'm at 34 MPG on average
Calculated by deviding the liters tanked by the kilometers driven.

On the highway I'm at 2200RPM and at these reves I also get 34,MPG on the computer for current consumption, is this normal?

On B-roads I do around 1500RPM, then I get around 44,6 MPG.
I can do around 800KM on one tank of diesel before the refule light pops up.

Is there anything I can do? Judging by the other numbers I'm reading here theres something wrong with the car, I drive very descent :O

 

i do 70 miles a day in my 1.9 16v. typically i get around 560 miles per tank full and im travelling fast, cruising between 80-90 mph on the motorway

i dont use revs below 2000 much as the peak torque is there and ive already had dmf/clutch and driveshafts issues and i think this is perhaps the worst place you can use the engine in, need to rev it more and not labour it with the turbo boost below 2000rpm

 

I could give a try shift at 2500/2800 RPM.

Can cleaning an EGR valve do anything for the fuel consumption?

 

I've been getting a measly 35 MPG on my GT JTDm. However, I tend to thrash it everywhere.
Having said that, until yesterday it had a split on ithe intake flexi pipe so that wouldn't have done it any favours. So I expect to get at least 37 mpg.
I do get 100SPG driving it though (smiles per gallon!)

 

Cream, are you forgetting to put it into top gear

 

nope... its in 6th a lot... i change up at 3500rpm to land at 2500rpm in each gear. whats your point ?

when my clutch start slipping it was always 2000-2200rpm with loads of boost - peak torque

i avoid it now because of what it does to the drive train

 

I've been looking around on the forum since my fuel consumption is quite high to my taste, especially as I don't trash it all the time.

I'm going to keep my eye on the engine temp gauge today but i'm pretty sure my car only rarely hits 90 degrees celcius, which could indicate en broken thermostat which could explain the high comsumption.

Does this sound about right?

 

it might be the reason. I changed mine (with flushing cooling system) since it was broken and it helped a lot. But - the gauge is not that correct as I heard, so make sure you replace thermostat only if it's really broken (mine was showing low 50C and now it shows about 80C with good thermostat)

and I don't think you will see better economy at 2,800rpm.

Just to make sure we are clear here - my car has 6-speed gearbox. as I know it makes huge-ish difference. I don't know what type 147 has with same engine

 

Possibly the saddest thread on AO - I'm with Geoff!

 

im with you.... nobody overtakes me on the way to work

however the cost of clutch, DMF and driveshafts on diesels does temper my driving style.. need to limit the damaging torque on diesels

 

To answer ARnovice first off: It is a 6 speed 1.9 JTD 16v 150 bhp

Yesterday at 23 degrees celsius outside the car was between 80 and 90 degrees, which was good, i also had a good economy with 17km/l to 18.5km/l at 120/130 kph.

I did notice that when I turn off the freeway and let it roll a while the temperature immediately drops like 10 degrees after rolling serveral 100 metres.

This morning at 7 to 10 degrees celcius I noticed the car between 70 and 80 degrees, also after rolling it a bit the temperature dropped to 70 fast.

I'm also wondering if 70 degrees is cold enough for the car to keep the choke on and mess up my fuel economy, does anybody know? If I need to start a new thread please let me know also :$

 

I must say that the temp of my engine really depends on the temp outside. This morning it was 10 degrees celcius outside and the gauge shows about 70 degrees, can this cause the car to use extra fuel?

When its hotter outisde it wil hit 80 and sometimes 90 degrees, I'm not really sure my thermostat is broken.
I'm going to have it checked with a computer this week, to see what temp the ECU is actually getting from the sensor and thermostat.

 

I regularly get 600+ miles on a full tank in my JTD16v on very mixed driving. It averages 50mpg every time I calculate by brimming the tank, resetting the mileage etc etc. Its a Turismo so doesn't have a display to check against.

 

I might need to check my calculations, gallons are not natural thing for me.
Please correct me if I am wrong:

to have 50mpg from 61 litres of fuel I would need to cover 680 miles, right?

I am using this site as a reference
Quick MPG calculator - Calculate miles per Gallon

 

I am getting my car checked this afternoon to see if the thermostat is broken or not.

Will let you guys know what happens

 

My 2007 GT blackline 1.9 16v jtdm

Computer currently showing 32.8 over last 1785 miles
It gets driven hard 75% of the time on duel carriage ways & twisty B roads

In use the full rev range up to 4500-5k

The car is mapped to 206bhp / 335 ftlbs with egr delete & k&n panel fitted

Loads of fun & worth the mpg loss to embarrass so called powerful petrol motors