I have recently changed jobs and my daily commute to work there and back is around 12 miles and im worried about the dpf getting damaged with constant short journeys given the fact that this component is not covered under warranty. My question is would i be better off trading the car for a petrol FR or would the dpf be ok?
-
Welcome to our new sponsor Lecatona, a brand dedicated to enhancing performance for VAG group sports cars, including SEAT, Audi, Volkswagen and Škoda. Specializing in High Pressure Fuel Pump (HPFP) upgrades.
i only do 9 miles to work and then 9 miles back again but its along an 'A' road at roughly 60mph and never had DPF light on within in 6 months of owning the car 
*TOUCH WOOD*
lol
*TOUCH WOOD*
lol
Dunc C
Guest
to give you an example, i do delivery driving in my car. i've never had the DPF light come on (touch wood). all you need to do is keep an eye out for the signs of the DPF regeneration cycle. Higher idle about 1000rpm, You may also hear a barking like noise as your driving along with it kicks in. when this happens just give the car a 5-10 min high rev burst on a dual carriage way when you can. I would say delivery driving is one of the most short journey intensive kinds of driving, so if it's fine for me it's fine for you. it's all down to how you drive.
hope this helps
hope this helps
My daily comute is just 4.5 miles each way which is roughly 1 mile at 30, 1 mile at 40 then 2 miles which are supposed to be 60 but tend to be crawling at 10-20. Although, the 30 and 40 tend to be crawling too.
Had car now since end oct and no warning light.
i think ive once or twice had the regernation take place as ive noticed the smoke/steam from under the bonet when stationary and the 1000rpm idle.
All that commuting being said, every month, i have at least a 3 hour journey in top gear with the revs about 2200-2500 so that should keep me clean.
As a systems designer, i do feel that the DPF is a poor/underengineered system.
There is no harm in designing something which needs to "regenerate" itsself, however its a shoddy compramise when you need to rely on the some chance external happenings to aid this process.
By chance happening, i mean, that you are in a position to drive in such a way that the exhaust gas temperature is high enough to regenerate the DPF.
Even just sitting stationary and holding a high number of rev's isnt going to give a high temperature.
- 3000rpm, for example, by just holding the rev's there when stationaly will not use much fuel, and so not produce much heat.
- holding the same rev's going down a steep hill in a high gear where you need to accelerator will produce very cool gasses, under 100c as your just moving ambient air.
This is why the manual disctates a minimum speed and rpm. The rpm provides the air flow rate for the DPF and the speed (which requires power and fuel) provides the exhaust gas temperatre required.
The DPF should produce its own heat from the oxidation of the unburnt fuel thats injected just after combustion is complete, and it does, but its efforts will be hampered by low exhuast gas temperature.
A quick burst wont do much in the long term. Its not likle blowing dust out a filter with an air hose, the regeneration of the DPF is actually the carbon particles being burnt, much like coal dust being burnt. It takes time to burn off the soot.
This is all why i think they are a poor design. The problem is that the manufacturers have to include this but need to keep the cost down, so its minimaly sized and employes a crude and unreliable management technique.
Stuart
Had car now since end oct and no warning light.
i think ive once or twice had the regernation take place as ive noticed the smoke/steam from under the bonet when stationary and the 1000rpm idle.
All that commuting being said, every month, i have at least a 3 hour journey in top gear with the revs about 2200-2500 so that should keep me clean.
As a systems designer, i do feel that the DPF is a poor/underengineered system.
There is no harm in designing something which needs to "regenerate" itsself, however its a shoddy compramise when you need to rely on the some chance external happenings to aid this process.
By chance happening, i mean, that you are in a position to drive in such a way that the exhaust gas temperature is high enough to regenerate the DPF.
Even just sitting stationary and holding a high number of rev's isnt going to give a high temperature.
- 3000rpm, for example, by just holding the rev's there when stationaly will not use much fuel, and so not produce much heat.
- holding the same rev's going down a steep hill in a high gear where you need to accelerator will produce very cool gasses, under 100c as your just moving ambient air.
This is why the manual disctates a minimum speed and rpm. The rpm provides the air flow rate for the DPF and the speed (which requires power and fuel) provides the exhaust gas temperatre required.
The DPF should produce its own heat from the oxidation of the unburnt fuel thats injected just after combustion is complete, and it does, but its efforts will be hampered by low exhuast gas temperature.
A quick burst wont do much in the long term. Its not likle blowing dust out a filter with an air hose, the regeneration of the DPF is actually the carbon particles being burnt, much like coal dust being burnt. It takes time to burn off the soot.
This is all why i think they are a poor design. The problem is that the manufacturers have to include this but need to keep the cost down, so its minimaly sized and employes a crude and unreliable management technique.
Stuart
Thanks for the indepth reply stuart, i agree with you that the regen system is poorly designed and is abit of a pain in the arse tbh. I dont want to change me car as it hasnt let me down yet and it nearly two yrs old (touch wood) and also the fuel consumption i great for a performance car.
Why do all these people have TDI 170's when they only do a handfull of miles to work and back?
Don't they know they need to be doing 20k miles a year to make a diesel pay these days?
Don't they know they need to be doing 20k miles a year to make a diesel pay these days?
I agree if you do a handful of miles a TDi may not be the best choice but it certainly isn't 20K to make a diesel pay. I would love to see a break down of the figures that back this up (have read this a lot in the press recently).
On 12K a year I'm saving money, there are a lot of other factors to take into account.
Not going into the figure again but many people including the press argue you need to take into account a TDi is more expensive to buy.
Yes but you will probably get back that difference or more when it comes to resale. Nobody wants petrol cars nowadays.
Case in point my Cupra, still sat at a SEAT dealer unsold almost 5 months since I traded it in at the Audi garage. Price drops each time I look, I reckon by time the car is 2 years old it will be worth 50% of the original price.
What a load of bull, I agree you need to be doing more than a few miles to work and back but nowhere near 20k a year. Even if you do 12k a year you are saving the pennies, even around town in a derv you will be very unlucky to get less than 30mpg, and in a petrol you will have to do a decent run to get more than 30mpg...
Phil, im keeping an eye on your Cupra, when I can get it free with a tank of petrol I might get it for weekend fun
From when I did the figures it's about £700 saving in fuel on 12K a year with a diesel.
Yes a diesel is more to buy but you will probably make the extra back at resale so that evens itself out.
Road tax is cheaper mine is £130 a year or thereabouts, not sure what the FR TDi is but it's lower than the petrol.
Servicing maybe slightly more not massive. Struggled to get the figures but can't imagine it being a massive amount more, not anymore than the saving in road tax.
Dave is right, even round town you are getting near double the mpg.
To the OP, I would keep the FR TDi unless you start having lots of problems. Cost to change would be silly unless you went for a used FR Petrol.
I would personally bear it in the back of my mind that is the DPF light does come on, then you need to give it a good run to clear it.
Yes a diesel is more to buy but you will probably make the extra back at resale so that evens itself out.
Road tax is cheaper mine is £130 a year or thereabouts, not sure what the FR TDi is but it's lower than the petrol.
Servicing maybe slightly more not massive. Struggled to get the figures but can't imagine it being a massive amount more, not anymore than the saving in road tax.
Dave is right, even round town you are getting near double the mpg.
To the OP, I would keep the FR TDi unless you start having lots of problems. Cost to change would be silly unless you went for a used FR Petrol.
I would personally bear it in the back of my mind that is the DPF light does come on, then you need to give it a good run to clear it.
Using the offical figures for the leon FR 2L petrol and diesel doing a combined, say 400 mile journey.
Diesel @ 47mpg uses 8.51gal, or 38.6L (know 47 is possible as ive had 45 sitting at 80)
Petrol @ 35mpg used 11.42gal, or 51.9L
Diesel costs 96.9p/l so the trip costs £37.40, or 9.35p/mile fuel
Petrol costs 88.9p/l so the trip costs £46.13, or 11.54p/mile fuel
So, using combined official figures, the diesel costs 2.19p/mile on fuel less to run than the petrol.
So the anual fuel savings are:
@ 7.5K: £164
@ 10.0K: £219
@ 12.5K: £274
@ 15.0K: £329
@ 17.5K: £383
@ 20.0K: £438
@ 25.0K: £548
@ 30.0K: £657
If you then account for tax and insurance you have additional savings there. Service cost i noticed at my dealer is Cheaper! (Diesel £175, Petrol £195 for 1st/10K mile service)
Also, the diesel engine has more power (and hence more torque) at any given RPM than the petrol, up untill 4400rpm when the petrol keeps giving more power so for most in town and even on the open road driving, the diesel will be a more powerfull drive (note figures in kW, not HP):
Petrol Diesel
RPM Nm kW Nm kW
1000 180 4 200 15
1500 240 8 300 47
2000 280 45 350 70
2500 280 65 350 92
3000 280 80 330 105
3500 280 100 310 116
4000 280 120 290 124
4500 280 130 290 125
5000 280 150 200 100
5500 260 150 - -
6000 240 150 - -
6500 220 145 - -
Stuart
Edit: sorry, the table isnt desplaying properly but you get the idea i think
Diesel @ 47mpg uses 8.51gal, or 38.6L (know 47 is possible as ive had 45 sitting at 80)
Petrol @ 35mpg used 11.42gal, or 51.9L
Diesel costs 96.9p/l so the trip costs £37.40, or 9.35p/mile fuel
Petrol costs 88.9p/l so the trip costs £46.13, or 11.54p/mile fuel
So, using combined official figures, the diesel costs 2.19p/mile on fuel less to run than the petrol.
So the anual fuel savings are:
@ 7.5K: £164
@ 10.0K: £219
@ 12.5K: £274
@ 15.0K: £329
@ 17.5K: £383
@ 20.0K: £438
@ 25.0K: £548
@ 30.0K: £657
If you then account for tax and insurance you have additional savings there. Service cost i noticed at my dealer is Cheaper! (Diesel £175, Petrol £195 for 1st/10K mile service)
Also, the diesel engine has more power (and hence more torque) at any given RPM than the petrol, up untill 4400rpm when the petrol keeps giving more power so for most in town and even on the open road driving, the diesel will be a more powerfull drive (note figures in kW, not HP):
Petrol Diesel
RPM Nm kW Nm kW
1000 180 4 200 15
1500 240 8 300 47
2000 280 45 350 70
2500 280 65 350 92
3000 280 80 330 105
3500 280 100 310 116
4000 280 120 290 124
4500 280 130 290 125
5000 280 150 200 100
5500 260 150 - -
6000 240 150 - -
6500 220 145 - -
Stuart
Edit: sorry, the table isnt desplaying properly but you get the idea i think
Also need to take into account:
The FR Petrol is recommended to run on 98RON or above petrol which bring the price per litre closer to diesel.
35 mpg is unrealistic from the FR petrol, I had the Cupra which is almost the same economy and 30 mpg was more like it. Could maybe add 1 mpg on that for the FR petrol.
Will have to try and dig out the figures I came up with.
The FR Petrol is recommended to run on 98RON or above petrol which bring the price per litre closer to diesel.
35 mpg is unrealistic from the FR petrol, I had the Cupra which is almost the same economy and 30 mpg was more like it. Could maybe add 1 mpg on that for the FR petrol.
Will have to try and dig out the figures I came up with.
Absolutley agree with this.
Also diesel mid-range is far greater than petrol (apart from turbos) I looked at 3 series petrol and diesel and although the 0-60 time was the same the mid range of the diesel blows the petrol right out of the water
Good points you raise above which although a diesel might sound like an old tractor at times the real world driving is second to none, the low down grunt is phenomenal and you'd be hard pressed to be left behind in the mid-range, its traffic light grand prixs which let the side down!!!! However I find 45mpg difficult to believe, you must be very lucky, my FR never got anymore than about 40mpg at 80mph motorway runs and that was in 40000 miles of motorway driving!!!!
My average was never much more than 40 with a mixture of driving. (Perhaps my right foot is too heavy!!!!) ![[:@]](/forums/styles/seatcupra/oldforumsmileys/furious.gif "Furious [:@]")
I noted when I got my FR that is was only £400 more to buy over an equivalent age/mileage petrol. I personally saved that difference in 6 months worth of fuel given my mileage.
Generally speaking, it's 10% more cost at the pump for 25% more mileage.
Generally speaking, it's 10% more cost at the pump for 25% more mileage.
Read my first post, i stated that i recently changed jobs, my previous job involved abit of mileage hence buying the tdi leon, now im not doing the mileage due to my work being alot closer to where i live (6 miles to be precise).
Similar threads
- Question
