how do you drive a TDCi?

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Sesquepidilian
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Re: how do you drive a TDCi?

Postby Sesquepidilian » Thu Apr 19, 2012 21:26 pm

.blitz wrote:
mrmonkfinger wrote:This system automatically turns the engine off when the car is stationary to save fuel

How well does this work in practice?

You're waiting at the lights in winter, heater/radio/lights/wipers on and the engine turns off :? presumably everything else carries on working. What about power steering/brakes. And stop/start crawling in traffic? Must give the starter a workout.


The starter is completley different compaired to a "conventional" engine. Some of the more trick systems can control the specific movement of the piston.

Personally, with 90k miles but I'd be well happy of 55-ish mpg. Turbos probably well past it's best, fuel system too; \I'd bet there's all kinds of wear and tear in there that, collectively, bring the figure down.

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bluechair84
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Re: how do you drive a TDCi?

Postby bluechair84 » Tue Apr 24, 2012 20:19 pm

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.

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Briggo
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Re: how do you drive a TDCi?

Postby Briggo » Thu Apr 26, 2012 06:48 am

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.

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The Rookie
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Re: how do you drive a TDCi?

Postby The Rookie » Thu Apr 26, 2012 12:09 pm

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!

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bluechair84
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Re: how do you drive a TDCi?

Postby bluechair84 » Thu Apr 26, 2012 12:33 pm

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.

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The Rookie
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Re: how do you drive a TDCi?

Postby The Rookie » Thu Apr 26, 2012 12:45 pm

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

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bluechair84
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Re: how do you drive a TDCi?

Postby bluechair84 » Thu Apr 26, 2012 12:53 pm

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.

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mrmonkfinger
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Re: how do you drive a TDCi?

Postby mrmonkfinger » Thu Apr 26, 2012 13:04 pm

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.

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mrmonkfinger
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Re: how do you drive a TDCi?

Postby mrmonkfinger » Thu Apr 26, 2012 13:06 pm

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.

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CraigXXL
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Re: how do you drive a TDCi?

Postby CraigXXL » Thu Apr 26, 2012 15:22 pm

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.

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bluechair84
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Re: how do you drive a TDCi?

Postby bluechair84 » Fri Jun 01, 2012 12:41 pm

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?

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bails87
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Re: how do you drive a TDCi?

Postby bails87 » Fri Jun 01, 2012 13:14 pm

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.
MTB/CX

"As I said last time, it won't happen again."

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YeehaaMcgee
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Re: how do you drive a TDCi?

Postby YeehaaMcgee » Sun Jun 03, 2012 14:38 pm

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.

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bluechair84
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Re: how do you drive a TDCi?

Postby bluechair84 » Sun Jun 03, 2012 16:27 pm

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

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CraigXXL
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Re: how do you drive a TDCi?

Postby CraigXXL » Tue Jun 05, 2012 17:11 pm

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
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Re: how do you drive a TDCi?

Postby Lapierre t 400 » Tue Jun 05, 2012 17:25 pm

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
I assume this is French petrol - be careful in reverse - the car will retreat rapidly at the least provocation.

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mrmonkfinger
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Re: how do you drive a TDCi?

Postby mrmonkfinger » Wed Jun 06, 2012 10:03 am

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.

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bluechair84
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Re: how do you drive a TDCi?

Postby bluechair84 » Wed Jun 06, 2012 10:08 am

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?

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CraigXXL
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Re: how do you drive a TDCi?

Postby CraigXXL » Wed Jun 06, 2012 19:40 pm

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
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Re: how do you drive a TDCi?

Postby reformedfatty » Thu Jun 14, 2012 14:07 pm

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


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