how do you drive a TDCi?

bluechair84

So, I did fuel filter, oil filter, air filter and new oil a few weeks back now and haven't seen an increase. Still getting around 53. As Sesquesomethingorother said, maybe it's the greater wear and tear on the components bringing it down. I've just ticked over 100k so it's getting on a bit. Maybe it's my daily commute... I'm yet to do a long motorway run when I'm not in a rush to see if I could get higher than this.

Briggo

bluechair84 wrote:

So, I did fuel filter, oil filter, air filter and new oil a few weeks back now and haven't seen an increase. Still getting around 53. As Sesquesomethingorother said, maybe it's the greater wear and tear on the components bringing it down. I've just ticked over 100k so it's getting on a bit. Maybe it's my daily commute... I'm yet to do a long motorway run when I'm not in a rush to see if I could get higher than this.

If your daily commute isn't sitting at a steady speed for a long period (i.e. dual carriage/motorway) of time 53 mpg is bloody good.

My commute is all A road/city driving and I get around 40-45mpg depending on traffic volumes, I'm way more than happy with this. Beats my previous TDCi with 35mpg on the same route.

The Rookie

As an engineer who has worked in powertrain for 23 years, and spent some time working on the dark side (Diesel) I have to say a lot of stuff in this thread is complete BS.

Glowplugs, yes they are left on for longer, it's primarily for emissions (CO/HC not CO2) reasons, the fuel economy benefit is vanishingly close to zero as you have the losses in powering the glow plugs as well.

The Fiesta/Focus 1.6 Diesels are the same as the same size Pug engines.

Unless running on very light throttle, keep over 1600rpm on the 1.4/1.6 (about 1500rpm on 2.0) so you keep the turbo spinning and running 'excess air;' for better combustion, a 6 speed Mondeo at 60mph on normal roads is more economical in 5th than 6th by about 6%, on a straight level road with no detrimental factors like winds etc it's about 2% more economical in 6th (real world test data from when I was at Ford).

My Old Montego 2.0 TD averaged over 55mpg easy, but no-one would drive such a slug now!

bluechair84

The Beginner wrote:

Unless running on very light throttle, keep over 1600rpm on the 1.4/1.6 (about 1500rpm on 2.0) so you keep the turbo spinning and running 'excess air;' for better combustion, a 6 speed Mondeo at 60mph on normal roads is more economical in 5th than 6th by about 6%, on a straight level road with no detrimental factors like winds etc it's about 2% more economical in 6th (real world test data from when I was at Ford).

This is the kind of thing I was hoping to discuss, whether at 40-50 in fifth at around 1500 rpm I was laboring the engine too much. The turbo doens't really increase the toruque until around 1800-2000rpm.

The Rookie

Try running it in 4th for a few days, or drive in 4th, coast in 5th (if you can be bothered!) where appropriate.

bluechair84

I've got my foot on the clutch at every opportunity. Even turn off the engine at lights I know I'll have to wait at for prolongues stays! Everything I do only gets me 53. I'll experiment with gearing.

mrmonkfinger

Briggo wrote:

If your daily commute isn't sitting at a steady speed for a long period (i.e. dual carriage/motorway) of time 53 mpg is bloody good.

I'm fairly sure he said his daily commute was sitting at a steady (and not that high) speed for the whole trip.

mrmonkfinger

The Beginner wrote:

The Fiesta/Focus 1.6 Diesels are the same as the same size Pug engines.

Are there any variations in turbo & ecu?

PS thanks for bringing some sanity to the thread.

PPS last weeks entire motoring, >300 miles, two long trips + a few round town short stuff, returning 49mpg this time. Was showing 51 for just the first long trip.

CraigXXL

It was me that said about the glowplugs in the first place. I have read what you have said but none of that explains why after changing my glowplugs my mpg went from 36 to 45mpg over the same stop/start 9 mile commute.
I changed the plugs myself and found that 3 out 4 had failed, nothing else was changed or serviced. I still run the car on Morrisons cheapest, regulary check tyre pressures and oil levels are correct. The only things that will have changed since changing the plugs is the oil has got dirtier, the tyres have worn more and the weather has got worse.
I'm not the only one to have noticed this increase in MPG after changing the glowplugs as others have testified to at STDrivers and TalkFord forums.

bluechair84

To re-raise the issue of glowplugs, if the engine is hot, do I need to wait for the light to go out? It doesn't seem to be temp dependant (at least, not the temp I'm reading on the dash) and just seems to be timed. It's never on longer or shorter than usual. So, whe I sotp and turn off at reds I'm having to predict when they'll change and start the glow plugs. Do I actually need to wait for the light if the engine has only been off for minutes at the most?

bails87

My TDCi Focus (55 plate) doesn't turn the glowplugs on (or at least the dash light doesn't come on) if the engine is still warm. The rest of the orange and red startup lights come on for a few seconds, but not the glow plugs.

YeehaaMcgee

bails87 wrote:

My TDCi Focus (55 plate) doesn't turn the glowplugs on (or at least the dash light doesn't come on) if the engine is still warm. The rest of the orange and red startup lights come on for a few seconds, but not the glow plugs.

Peugeot HDIs don't either, but all VWs I've seen show the warmup light.

bluechair84

How very strange, Mine comes on for the same length of time every time I fire her up...

CraigXXL

The glowplug light normally indicates the period of time it takes for them to warm up and be ready for you starting the car. When it isn't lit up they are ready but they can come on whilst the engine is running to indicate a problem.

Lapierre t 400

You could always get someone to scan the car for you to see if any fault codes come up.
alternatively,go out onto a motorway/dualcarriage way and boot it through the gears.black smoke might be emmitted this is due to cr£p being rattled free from the exhaust etc

mrmonkfinger

CraigXXL wrote:

none of that explains why after changing my glowplugs my mpg went from 36 to 45mpg over the same stop/start 9 mile commute.

Maybe the ECU goes into a "limp home" mode if the plugs are all gone.

bluechair84

I doubt the glow plug light being set to a time suggests the engine is on it's way out. No black smoke, all is well. I often switch off at red lights, and then wait for the glow light to go out before firing her up again. But do I need to do this if the engine is already up to temperature?

CraigXXL

mrmonkfinger wrote:

CraigXXL wrote:

none of that explains why after changing my glowplugs my mpg went from 36 to 45mpg over the same stop/start 9 mile commute.

Maybe the ECU goes into a "limp home" mode if the plugs are all gone.

Only ever had the one issue with my TDCI and that was the EGR. Performance was and still is great only difference it runs a bit smoother and MPG is up.

Bluechair, I wasn't suggesting your engine is on the way out just explaining what the glowplug light is telling you when lit.

reformedfatty

Only 53? my focus 1.8 tdci regularly turns in 35, seems to run normally but the computer doesnt know whats wrong.

bails87

35mpg?! Ouch!

I have a ~13 mile commute, on twisty country roads with 5-10 minutes of suburbs/sitting in traffic at either end, and even when I drive like a pleb (not necessarily fast, but getting back up to speed quickly after a slow corner) I don't get under 45mpg.

snowjho

bluechair84 wrote:

I've got my foot on the clutch at every opportunity. Even turn off the engine at lights I know I'll have to wait at for prolongues stays! Everything I do only gets me 53. I'll experiment with gearing.

I Thought its better to not have your foot on the clutch and 'freewheel' as more fuel is used to stop the engine from stalling. I try to depress the clutch as late as possible when stopping.

In my focus tdci 1.6 (110) 2009 i get 60mpg. I speend most of my time commuting on m3/m25 (30 miles/40min) ive often found its happier at 70 then 60. Ive become a bit mpg obsessed layely. 2,000 rpm or just over and the car cruises along nicely.

bluechair84

never heard this before. I just try to keep the engine turning is slowly as possible to reduce the number of times the cylinders are firing. And although engine braking is minimal in higher gears, you don't have to keep up the revs to overcome this when coasting. It's surprising how far you can coast!

bails87

bluechair84 wrote:

never heard this before.

I've heard it, admittedly only on top gear.

Essentially, when the clutch is up, the engine is (at least partly) kept ticking over by the wheels 'feeding' movement back into the engine. When you press the clutch down, the engine needs fuel (not much though, as it's not doing much) to keep itself going.

And I reset the mpg counter and have just been doing my traffic/blast/traffic commute, I'm down to 42mpg :shock: I need a motorway cruise to get it back up!

bluechair84

god damn it... there's no action without consequence is there. I've tracked 5000 miles and averaged 53mpg.

WisePranker

bails87 wrote:

bluechair84 wrote:

never heard this before.

I've heard it, admittedly only on top gear.

Essentially, when the clutch is up, the engine is (at least partly) kept ticking over by the wheels 'feeding' movement back into the engine. When you press the clutch down, the engine needs fuel (not much though, as it's not doing much) to keep itself going.

'Tis true.

When you're rolling along with the throttle closed, the amount of fuel injected into the engine is minimal. At higher engine speeds like when decelerating on the motorway, the fuel is pretty much cut off when the throttle's closed. It's to help improve fuel economy and reduce emissions.
If you freewheel with the clutch pressed or the car in neutral, more fuel is injected into the engine to keep it running.

Northwind

In the course of this thread I aquired another TDCI, a 2.2 this time. And I drive it everywhere in clouds of soot and tyre smoke. Hope that helps.

bluechair84

Let me know what the fuel economy is like with this driving style, and if it hasn't gone down much I'll give the tyre smoking thing a try. No wait... mine's a 90hp engine... it has all the performance of a mobility scooter

Thewaylander

Northwind wrote:

In the course of this thread I aquired another TDCI, a 2.2 this time. And I drive it everywhere in clouds of soot and tyre smoke. Hope that helps.

FR leon, i drive like this, screw econemy lol :P

bobpzero

this might help

Northwind

bluechair84 wrote:

No wait... mine's a 90hp engine... it has all the performance of a mobility scooter

My Focus had the 90 horse enduro engine... Sure it's not mighty but the power delivery was fantastic, genuinely miles nicer to drive stop-start than the 130 or 155 versions. Lovely wee engine.