how do you drive a TDCi?
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YeehaaMcgee wrote:
That quote up there says the glowplugs are active for a max of 30 seconds. The engine running temperature (ie, the water temperatre), and the temperature inside the cylinders will be very different.CraigXXL wrote:The problems with diesels are they perform so poorly when cold, add to that cast iron engine blocks and they take a long while to warm up unlike petrol engines. Mine can take a good 20 minutes to warm up and after a very cold night even longer whilst the wife's petrol car will be warmed up within a few minutes. The glowplugs create the warm engine efficiency until it has actually warmed up properly.
No, they usually stay on for much longer but switch off whne you go above say 2.5k rpm, then back on when the engine goes under 2.5k rpm till the engine is at operating temperature, it takes a while for the iron blocks to warm up just right.
No doubt the engine would work without them doing this but its mainly for emissions.
Something like that.
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Dunno where Craig got his quote from, but it says right there...CraigXXL wrote:There is a maximum after-glow time of 30 seconds at -20°C or lower. At temperatures above 50°C there is no after-glow phase.
Which is exactly what I was told, and led to believe for years. The glowplugs staying on thing, sounds to me like some pterolhead has been guessing at things.
Now, I may be wrong, you may be wrong. But it would appear that whatever Craig's source was, agrees with what I've been taught about diesel engines.
Oh, and as for "operating temperature", and the engine taking a while to reach around 90degrees thing? Well, yeah, that's the whole block warming up, and the engine oil, coolant, etc etc. That won't be affected by the glowplugs.
It just stands to reason that the in-cylinder temperature, which is where the glow plugs effect is constrained to, reaches detonation temperature very very quickly.0 -
The glowplugs are just warming the cylinders up to ensure efficient combustion until the rest of the engine is warmed up.0
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YeehaaMcgee wrote:I still reckon they make no difference.
:roll:0 -
I'm sure your little rolleyes suggests that there's an in-joke facepalmey thing in there somewhere, but for the rest of us who don't share your unconscious, uncommunicated thoughts, would you care to fill us in on what you mean?0
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I've edited it for you to understand a little better, why would engineers do it if it made no difference.
For sheer laughs?
This took me about 2 seconds to find with a quick google search, you sitting there dismissing it without anything to back it up is nonsense, as I said engineers won't set them to stay on after ignition for a laugh will they.
http://www.beru.com/products/diesel-col ... lugs-ge-gn0 -
Look, I don't actually "know" - which is why I'm curious. However, all the evidence points to the fact that glowplugs will not stay on for a long time after the engine starts, so little that efficiency can't possibly be impacted.
From YOU OWN link...This means: the glow plug not only heats prior to and during the starting phase, but also up to 180 seconds after starting
180 seconds. That's 3 minutes. You still think that changing your glowplugs will have a noticeable hit on economy? Because frankly your evidence that's supposedly supporting that hypothesis, is proving the opposite.0 -
I guess if you are just using the car for 5 min runs to drop the kids off at school and to the shops it may have an impact. But until we see figures for how much fuel is wasted/not combusted on cold starting it is impossible to put figures on it.0
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Well, I've done the service and over 500 miles I've filled up twice and got 49mph and 53 mpg... I might have to expect that this is the car's capability. I'd hoped for a bit more, but it's still slightly cheaper per mile than the 407 was, tax is 145 pounds less and insurance is lower so all in all it's much better.0
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YeehaaMcgee wrote:Ah. There's your answer.
Pug diesel engines are just in a different class.
Just so as you know, the (05-11) Focus 1.6 and 2.0 diesels use an engine jointly developed on by Ford and Peugeot. The 1.8 used an previous generation Ford block, I'm not sure its as good as the 1.6 or 2.0. I have no idea about the current Focus. http://en.wikipedia.org/wiki/Ford_DLD_engine
bluechair -
I get a nose under 50mpg doing my twice weekly 100mile+ motorway/a-road/country lane run at up to about 75mph, and that's in a 2006 2.0 estate. I use cruise control a lot. If I dawdle along at 60mph it gets about 65mpg. That's GPS speedo and pump receipts, btw, not trip computer. My speedo and trip computer both overread by 3-4%.
In honesty, I'd expect a bit better out of the 1.6. :?0 -
The one thing I can point to is it's the 90bhp engine, not the 110bhp. It might just be a bit too gutless to manage it's weight.0
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My mate has a 90bhp Eco Focus, bought on the strength of the 115bhp Ti-VCT I used to own. The Eco has a useful amount of low rpm torque but elsewhere it feels a bit subdued, like driving the with the air con on.0
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I wonder why the 90bhp eco will get higher mpg than my 90bhp (other than it being an estate). They do have eco tyres which I wouldn't want to go for, I've heard bad things regarding braking distances.0
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Most important if your trip is less than 10 miles your diesel engine wont even get warm, and then there econemy is't very good.
Diesels are slow slow to warm up in comparison to a petrol engine so for short journeys an effiecient petrol is normally a better option.
And as to pug engines, who cares when the cars are made of tin foil and bits fall off them
which i have seen 
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YeehaaMcgee wrote:Oh, are we back on the warmup malarkey again?
They do take sodding ages to warm up.
More of a pain in winter... If you're one of those without a magic electrical windscreen.0 -
However, the actual cylinder temperature is not the same as the coolant temperature.mrmonkfinger wrote:YeehaaMcgee wrote:Oh, are we back on the warmup malarkey again?
They do take sodding ages to warm up.
More of a pain in winter... If you're one of those without a magic electrical windscreen.
The thermostat doesn't even open to begin cooling the engine on most diesels until 90degrees C. Now it may take the head and the engine block a while to reach that, but the internal cylinder temperature will be far, far hotter.0 -
I might be wrong, but isn't one of the functions of the glow worms to preheat air to allow more complete combustion?
But again, without figures is really hard to say what the difference in fuel is.0 -
Even if it is, it's already been posted, that the experts claim that the very maximum time a glowplug will be on is 3 minutes, In the coldest conditions.supersonic wrote:I might be wrong, but isn't one of the functions of the glow worms to preheat air to allow more complete combustion?
But again, without figures is really hard to say what the difference in fuel is.0 -
YeehaaMcgee wrote:Even if it is, it's already been posted, that the experts claim that the very maximum time a glowplug will be on is 3 minutes, In the coldest conditions.
only the engine management unit knows for sure when you're running at normal economy, and that will be working from an engine block coolant temperature sensor
from experience, I lose economy on short trips in cold weather, noticably so.0 -
And air-mass meters, and exhaust meters etc etc etc.mrmonkfinger wrote:only the engine management unit knows for sure when you're running at normal economy, and that will be working from an engine block coolant temperature sensor
Seriously, the cylinders heat up to operating temperature much faster than the block does. Hell, if it didn't then a diesel engine just wouldn't work unless it was in a furnace.0 -
yeehaa wrote:Seriously, the cylinders heat up to operating temperature much faster than the block does. Hell, if it didn't then a diesel engine just wouldn't work unless it was in a furnace.
true... and all this make precisely squat difference to a 45 minute tripbluechair84 wrote:I wonder why the 90bhp eco will get higher mpg than my 90bhp (other than it being an estate). They do have eco tyres which I wouldn't want to go for, I've heard bad things regarding braking distances.
Round town the eco engine does that automatic stop-start thing. Plus other optimisations.These low-emission, high-economy models come with fuel-saving measures that include longer-legged gearing, an intelligent alternator, economy-optimised engine management, low rolling resistance tyres, wind-cheating aerodynamic modifications, low-friction oils, a low-drag alternator and air conditioning drive-belt system and a gearchange indicator light.
In addition, the 109bhp 1.6 TDCI engine is optionally available with auto start-stop. This system automatically turns the engine off when the car is stationary to save fuel, in common with the similar systems pioneered by BMW and Mini over the past few years. We spent six months with this ultimate version of the Focus Econetic, to see how economical it is in reality and to discover whether its generally excellent qualities are enhanced by these eco modification0 -
The gear-change light surprised me. The only one I've seen is in my father's Golf 1.6TDI which he got brand new last year.
It suggests that you change up very low in the revs - much lower than I would have considered. I think it's at roughly 1,200 RPM if memory serves me right. Basically just slightly above tickover!0 -
YeehaaMcgee wrote:It suggests that you change up very low in the revs - much lower than I would have considered. I think it's at roughly 1,200 RPM if memory serves me right. Basically just slightly above tickover!
that would certainly be an 'economical' acceleration :shock:
PS this weeks highly exciting ford economy update: 260 miles, 70-75 on motorways no holdups, but did follow a lorry round the a/b road section in one direction @ 45-50... 52mpg (showing 55 on the dash).0 -
How well does this work in practice?mrmonkfinger wrote:This system automatically turns the engine off when the car is stationary to save fuel
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.0 -
.blitz wrote:
How well does this work in practice?mrmonkfinger wrote:This system automatically turns the engine off when the car is stationary to save fuel
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.
Mixed reports on this, as they wont work until the engine is nice and warm, so for the first 10-15 minutes. Then if they break there very expensive to repair which pretty much wipes out there fuel saving. Also stop starting an engine are some of the worst points of strain on an engine :S0 -
You know i though I was the only one who was bit geeky about MPG.. i have an 05 BMW 320d - I have seen the MPG creep up in the last few months having noticed it drop by 1 or 2 MPG's over the winter. I only do 22miles per day total in my commute and have never bettered 41MPG (Cross country too) yet on motorway runs it quickly stretches to 49mpg + Wish I had bought the petrol.0
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Redhog14 wrote:You know i though I was the only one who was bit geeky about MPG.. i have an 05 BMW 320d - I have seen the MPG creep up in the last few months having noticed it drop by 1 or 2 MPG's over the winter. I only do 22miles per day total in my commute and have never bettered 41MPG (Cross country too) yet on motorway runs it quickly stretches to 49mpg + Wish I had bought the petrol.
I have the same car from the same year (163BHP). Averages in the low 40's driving local (but it's very mountanious around here). Average low 50's on a motorway run with cruise control on.2011 Canyon Nerve AM 5.0
2009 Specialized Rockhopper Disc
I might have alzheimer's but atleast I don't have alzheimer's0 -
.blitz wrote:
How well does this work in practice?mrmonkfinger wrote:This system automatically turns the engine off when the car is stationary to save fuel
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.0
