Petrol or diesel Leon SC

Jun 15, 2013
268
2
Without trying to sound completely useless (failed that then) are there likely to be DPF issues with a brand new car over its first 3 years? Surely filters will be checked and cleaned at service time. I'd have thought if this was such a major issue there would never be any sales of diesels anywhere.

Thanks for helping a complete novice :)

Si.

DPF's cannot be cleaned in the way ordinary filters are cleaned and are not part of any service schedule. They have to regenerate and providing your use allows regeneration's to take place when required you will have no issues. A regeneration normally takes about 15 miles or 20 minutes based on my personal experience but that was not with VAG cars.

If you use your car mostly in town for short journeys it will not get hot enough or run at a suitable speed for long enough for a regeneration to occur. Taking the car for a weekly thrash on the motorway will achieve nothing unless the ECU decides a regeneration is needed, in fact thrashing it will block the DPF faster since you will be making more soot. If you use your car mostly in town get a petrol. TSI's are brilliant, mine is very nearly as economical as my old diesel and when you take the difference in cost per litre into account my running costs are virtually identical.

My personal experience over 5 1/2 years with DPF cars has been fine. My old car did 37,000 miles in just over 5 years and never had an issue. Most of those miles were my commute which at 15 miles/30 minutes gave the DPF plenty of time to regenerate. But after driving the 1.4 TSI I was happy that it was a better drive than any diesel I had owned and after 4 months my opinion has not changed but the mpg at 46 ish is better than I expected.
 
Jun 15, 2013
268
2
Difference in price between petrol and diesel is only £800 and that is cancelled out over the 3 years due to residual values and the need to pay road tax.

When I bought in June the difference between the 140 PS petrol and the 150 PS diesel was £2000. In my estimates I allowed for getting 1/2 that back after 5 years based on previous experiences. Looking on here and at Honest Johns Real MPG site I estimated that a 150 PS diesel would average 54 mpg and the 140 PS petrol 44 mpg. The RFL is £10 cheaper on the 150 PS diesel. Petrol is about 5p a litre cheaper.

Over 5 years and 40,000 miles my fuel savings with a diesel would be about £850 at todays prices, add in the RFL and its still under £900. If I got the expected £1000 more in PX in 5 years time I would still be out of pocket.

In the past I have bought diesels because of the way they drive, hate modern torqueless, high revving engines petrol engines, love the lazy way a diesel drives. But the TSI drives just like a diesel but with a wider power band and less lag it was game set and match.

If I was doing a higher mileage I would still buy a diesel but it would need to be nearer 15,000 miles a year to tip the balance for me.
 

Psyman79

Active Member
Apr 19, 2012
24
0
Aberdeen, Scotland
Thanks for all the info.

Think i should be okay with the diesel, don't do a great deal of city driving since i moved a few months ago. Commute is mostly dual carriageway or fast A road so hopefully wont have any issues. Do quite a few trips to Glasgow/Edinburgh every year for gigs too (about 200 mile roundtrip).

The 1.4 TSI probably would've been fine for me but it doesnt come with a DSG at present and that is one of the main reasons for the new car.

Thanks again,

Si.
 

Bobanegra

Active Member
Oct 15, 2010
310
0
Stirling
The diesel/petrol debate is one I'm having with myself too, when I had my Leon FR TDI I was regularly doing up to 700 miles over a weekend but when I switched to the Boc I wasn't making these trips anymore so petrol seemed the better choice especially as the consumption figures between the two were pretty similar.

I don't think it'd be worth getting a diesel now as long drives are at a minimum and most of my journeys are relatively short so the engine wont get the chance to properly warm up therefore efficiency would be down. As things stand the efficiency of both the 1.4 and 1.8 TSI engines are excellent - both (on paper at least) better than my previous two cars in terms of road tax and fuel consumption… I guess I'm just waiting to see what figures the Cupra comes with.

I know holding off for a Cupra just to see fuel consumption figures is a bit against the point of owning one but it'd be nice to be able to gauge how much its going to cost me in road tax and petrol as well.

If I was forced to pick one from what's available now it'd be the 1.8 TSI DSG.
 

Fred99

Active Member
Sep 21, 2013
448
1
Granada, Southern Spain
DPF's cannot be cleaned in the way ordinary filters are cleaned and are not part of any service schedule. They have to regenerate and providing your use allows regeneration's to take place when required you will have no issues. A regeneration normally takes about 15 miles or 20 minutes based on my personal experience but that was not with VAG cars.

I found an excellent article about DPF on a VAG forum. Unfortunately I cannot post the URL as I have less than 15 posts but if you do a Google search on

"DPF Regeneration Information - Must read for all drivers of DPF equipped cars"

it should be at the top of the list. If anyone thinks it is useful perhaps they could post a proper URL link.
 

Hugo Nebula

Active Member
Dec 7, 2007
290
0
Manchester
Difference in price between petrol and diesel is only £800 and that is cancelled out over the 3 years due to residual values and the need to pay road tax.

Fuel price doesn't really affect me either as i currently use v-power or momentum 99 in the cupra which is the same price as diesel anyway.

I'll probably be doing about 10000 miles/year but my commute is only a 15 mile round trip.
I hadn't thought about there being issues with short distance driving, could well be what puts me off the diesel. I'm not very knowledgeable when it comes to cars, i just buy what i like at the time :)

Regarding my calculations, it was just to see what sort of MPG figures people are actually getting as my monthly savings over the Cupra are what is winning the argument with my wife.

Thanks for making me think more about diesel :)

Kind regards,

Si.

I've had a CR diesel for two years, with a Monday-Friday commute of 13 miles round trip and a few stop-start site visits in between. I've never had a problem with a DPF; I couldn't tell you if it's ever even come on!

"Your mileage may vary" is the Americanism, but it's true. Over the years I have found that my average MPG for all my cars is close to the urban figure, so I tend to use that in my calculations. It may be worth looking at your current MPG, and working out what percent it is worse ('cos it almost certainly won't be better) than the combined figures for your current car, then applying this rate to the manufacturer's figures for your choices.

That said, until Seat get their finger out and stick the DSG in the 184 BHP TDi Leon, I would prefer a Golf GTD or an Octavia vRS.
 

Shiners

Active Member
Jun 29, 2013
78
1
Scotland
VAG DIESEL PARTICULATE FILTERS

Courtesy of David Bodily Volkswagen Technical Support Specialist

Diesel Particulate Filter (DPF)

Detailed below is important information outlining the function and features of the Diesel Particulate filter which all members of your team need to be aware of.

Diesel particulate filters are becoming more commonplace on diesel engines, particularly sizes 2.0L upwards. This is in order to reduce the exhaust emissions as required by European legislation.

The prime reason for a DPF is to reduce particulate matter entering the atmosphere. Particulate matter is found in the form of soot, which is produced during diesel combustion. The DPF traps most of the soot which would normally travel down the exhaust and into the atmosphere. The DPF can hold a certain amount of soot, but not a huge quantity and therefore it needs to go through a process called ‘regeneration’ in order to clear the soot loading. When the soot goes through a ‘regeneration’ process it will be converted to a much smaller amount of ash. The ash is non-removable. There are two types of ‘regeneration’, passive and active.

During long motorway journeys, passive regeneration will occur. This needs no intervention from the engine control unit. Due to the raised exhaust temperatures on a long journey (temperatures between 350 and 500°C), the procedure occurs slowly and continuously across the catalytic-coated (with platinum) DPF. The catalytic-coated DPF is situated close to the Engine, therefore the exhaust gas temperature is high enough (500°C) to ignite the soot particles. Due to this soot is burned-off and is converted into a smaller amount of ash.

Active ‘regeneration’ is when the ECU intervenes when the soot loading in the DPF is calculated to be 45%. The procedure lasts for about 5 – 10 minutes. Specific measures are taken by the ECU to raise the engine exhaust temperature to above 600°C, these include switching off the exhaust gas recirculation and increasing the fuel injection period to include a small injection after the main injection. The soot particles are oxidised at this temperature.

The ECU will trigger a regeneration process, if for some reason this is aborted, ie. customer slows down, stops etc, the process will be resumed when regeneration conditions are once again met, above 60km/h (38mph). This will continue for 15 minutes.

If after 2 attempts of 15 minutes, a successful regeneration has not been possible, the loading will increase. At 50% soot loading, the ECU will continue to maintain maximum exhaust temperatures of 600°C to 650°C to cause a regeneration process. The system will try to run a regeneration process for 15 minutes. If unsuccessful, the system will repeat this process for a further 15 minutes, if still unsuccessful, the DPF light on the driver display panel will then be lit.

The owners handbook states, the DPF symbol lights up to indicate that the diesel particulate filter has become obstructed with soot due to frequent short trips. When the warning lamp comes on, the driver should drive at a constant speed of at least 60 km/h for about 10 minutes. As a result of the increase in temperature the soot in the filter will be burned off. If the DPF symbol does not go out, the driver should contact an authorised Volkswagen repairer and have the fault rectified.

At 55% soot loading the DPF light is lit on driver display panel. At this point the customer should follow the advice in the handbook. If they ignore this information and continue driving the vehicle until the soot loading reaches 75% without successful regeneration, additional warning lamps will light up. At this point the customer will also be complaining of lack of power, etc.

At 75%, regeneration is still possible with the use of the VAS tester. Only when the loading is above 95%, is it necessary to replace the DPF unit.

Operating Status System Response

45% DPF Load Level 1
Normal Regeneration

50% DPF Load Level 2
Regeneration at maximum exhaust temperatures

55% DPF Load DPF lamp
Regeneration from 60 km/h onwards
("See operating manual")

75% DPF Load DPF, SYS and MI lamp
Torque limitation, EGR deactivation,

Regeneration via VAG tester only
95% DPF Load Replace the DPF Unit

The Warranty department has confirmed that if there is no fault on the vehicle and DPF regeneration has been unsuccessful due to the customers driving style and the customers failure to comply with the instructions in the handbook, DPF replacement will not be paid for by warranty.

Common causes for complaint

• Frequent short journeys – Regeneration conditions are not met.
Not recommended for sale in the Channel Islands and inner city driving.

• Customers who continue to drive the vehicle with DPF light on – Continued
driving with the DPF light on and without successful regeneration results in
excessive soot loading of the DPF, to a point where it is above 95% loaded.
At this point regeneration is not an option and replacement of the DPF is
necessary.

• Fault 18434 particle filter bank 1 malfunction – Common fault code. This does
not only relate to the DPF itself, but the entire exhaust gas handling system. This
can be caused by defective temperature sensors, pressure sensors, additive
system components (if applicable), poor connections, wiring issues, etc.

Important Information

• Before diagnosing a problem vehicle or attempting to perform an emergency
regeneration, it is important to obtain a full diagnostic log and read out relevant
measured value blocks. These MVB’s contain important information on the
condition of the DPF system and are essential in diagnosing the fault. When the
DPF light is illuminated, it does not necessarily mean that the DPF requires
regeneration. For further advice, please contact Technical Support with the
information from the diagnostic log and MVB data.

• If a problem vehicle arrives with the DPF light, the engine management light and
the emissions light on. If during your diagnosis and reading of relevant MVB’s,
you find that the soot loading exceeds 75% (but is still below 95%), an
emergency regeneration procedure must be performed with the VAS tester.
Further to this, the customer needs to be educated. They need to understand
why the lights have appeared on the dash panel. Their attention needs to be
brought to the owners handbook instructions, so that they are aware of what the
DPF light means and what to do when it appears. This should prevent
unnecessary repeat visits for regeneration purposes.
I have also found that as the car gets older 30K+ miles, you will notice that the regeneration takes place more often.
ALWAYS, check your oil before any long journey, as DPF regeneration can use a fair bit of oil.

Some questions and answers that may help;
Question: The glow plug symbol is flashing. Why? What should be done?

Answer: The DPF regeneration has not been completed during normal driving and now DPF has reached its maximum saturation at which it can still be regenerated. The limit value depends on variant and Model Year, but is in the range of 105% - 125%.Possible causes for this are:

a.) Frequent short distance journeys, i.e. high soot loading while at the same time regeneration of the DPF does not take place because the conditions necessary were not fulfilled.

b.) Frequent interrupted regenerations, i.e. the engine was switched off during regeneration. Applies to short journey drivers who have at least fulfilled the conditions for triggering regeneration. If the glow plug light flashes, the vehicle

a.) Engine running since start for longer than 2 minutes.
b.) Calculated saturation higher than 80%.
c.) Coolant temperature over 70°C for at least 2 minutes.
d.) No DPF-relevant faults stored in system.
e.) A defined vehicle speed threshold must have been exceeded (e.g. for >80% loading, 100 km/h)


Question: Under what conditions is regeneration interrupted/ended once it has started?

Answer: Normally when regeneration has been successfully completed, or:

a.) After a maximum regeneration time (20 - 25 min.).
b.) If the engine is switched off or has stalled.
c.) If the engine is left idling for a long time (5 - 10 min.).
d.) If 1000°C is detected by the exhaust temperature sensor.
e.) If during regeneration, a fault is detected on the components relevant for combustion (injection/intake system).
If a regeneration is interrupted once started but before it has been 50% completed, the glow plug lamp flashes on the next engine start (cold or hot) and regeneration begins again once the operating conditions (see 3) have been fulfilled.

Question: How long does complete regeneration take? a.) In the most favourable case? b.) In the least favourable case?

Answer: a.) Under constant conditions, i.e. the exhaust temperature necessary for regeneration always lies above the required value, for example during motorway/cross-country driving, the average regeneration time is 10 minutes.

b.) Vehicle conditions such as long down-hill descents, frequent driving in the low-load range (city driving, idling) allow the exhaust temperature to fall. If the conditions for triggering regeneration were fulfilled, the active regeneration time can be extended up to 25 minutes (depending on engine type). If complete regeneration is not possible within this period, the regeneration will be interrupted.

Question: How does regeneration affect the oil life?

Answer: On each regeneration or attempted regeneration, a certain diesel fuel amount is injected into the engine oil which reduces the oil life. If the "INSP" light in the instrument cluster comes on, the engine oil is exhausted and must be changed. Failure to do so could damage the engine.
 

Lawto48

Active Member
Aug 26, 2013
61
0
Personally I think it's a catch 22 with a diesel (I have had 3) to get the torque and enjoy it !(which is great)you have to put your foot down which in turn gives you no better mpg figures than a petrol. To get the best mpg from a diesel you need to be on long runs on the motorway where it comes into its own. Plus I found trying to drive diesels on short journeys a lot harder to drive than petrol as gear change is crucial.

Picking up tomorrow:D. 1.8tsi fr man , black, tech pack, convienance pack, driver assist pack, seat sound, spare wheel, led light package
 

Psyman79

Active Member
Apr 19, 2012
24
0
Aberdeen, Scotland
Thanks to everyone for the help and advice :)

I've ended up ordering an Audi A3 S-Line 1.4 petrol, manual :)

Seat dealer wasn't offering me anything towards new car so A3 works out same monthly price as Leon SC.

Thanks again.

Si.
 

Swahealy

Active Member
Aug 26, 2013
107
0
London
A3 works out the same monthly as a Leon SC? Seat dealers are offering £1000 pounds deposit, Tech pack for free,4.9% APR or they should be? I will get my 1.8 TSI FR next weekend and I doubt that I could have got an A3 for a similar price. But who knows, I never bothered to enquire as a Golf mk7 1.4 GT was nearly £25 grand so I just assumed the A3 would be more.....
 

Swahealy

Active Member
Aug 26, 2013
107
0
London
Oh and reading all that guff about DPF in a diesel would REALLY put me off even thinking of driving one if I did not already think of it as tractor juice lol!! ( I know, modern diesels are alot better than they were:))
 

Psyman79

Active Member
Apr 19, 2012
24
0
Aberdeen, Scotland
Probably should've mentioned that i dropped the DSG from the Audi which is why it worked out the same, plus, Audi gave me metalic paint free so that was another £500 saving :)
 

Fred99

Active Member
Sep 21, 2013
448
1
Granada, Southern Spain
I currently have the Mk1 Leon with the 110PS 1.9 Diesel. I bought that because I liked the way it had so much torque at low revs. I have been more than happy with the fuel consumption which has averaged around 48-50mpg over its life.

When I first looked at the Leon mk3 as a replacement I automatically looked at the diesel options. I was tempted by the 2.0 150PS but eventually went for the 1.4 140PS petrol on the basis of a test drive where I was frankly amazed at the spread of torque from 1500rpm onwards - at least as good as my present car and probably better.

As for fuel consumption, I do a relatively low mileage now (about 6k) and the cost of fuel is not really an issue (it's cheaper here in Spain although diesel is still cheaper than petrol by about 6p a litre). The official consumption of the 1.4 petrol is exactly the same as my existing 1.9 diesel so I am happy with that - I am not looking for a reduction in cost.

The petrol option is nearly £2000 less and that means it will take me about 15 years to break even. Also it will be wonderful to not hear that diesel rattle when I start it up and it will be wonderful to see 6k+ on the rev counter after so many years! All my previous cars were high performance petrols and it was only retirement that forced me into a "sensible" option.

Only two weeks to go - I can't wait!
 

Shiners

Active Member
Jun 29, 2013
78
1
Scotland
Probably should've mentioned that i dropped the DSG from the Audi which is why it worked out the same, plus, Audi gave me metalic paint free so that was another £500 saving :)
I thought your main reason for changing car was to get an automatic?:confused:
 
Jul 29, 2013
859
1
Essex
I'm still not convinced by the cost comparison logic being used by some. It still looks like a tdi fr is cheaper than a 1.4 tsi fr over 3 years even if you don't drive it to me - notice here how the tdi is 2k more OTR but less a month because on a PCP you are paying for the depreciation and finance costs on the capital: http://www.nationwidevehiclecontrac...=51023&variant2=51026&Submit.x=82&Submit.y=18

Fuel and tax is just gravy, the more miles you do/longer you own it the more you save.
 
Last edited:

Psyman79

Active Member
Apr 19, 2012
24
0
Aberdeen, Scotland
Yeah, moving to an automatic was one of the main reasons for a new car, just decided that it maybe wasn't as important as i first thought. Now that i'm not living in the city centre my driving style has changed. See how i'm feeling in 3 years when PCP deal is over.

Si :)
 
Jun 15, 2013
268
2
I've ended up ordering an Audi A3 S-Line 1.4 petrol, manual :)

Seat dealer wasn't offering me anything towards new car so A3 works out same monthly price as Leon SC.

Find that very difficult to believe. When I bought my 1.4 TSI the best deal I could get on a Golf 1.4 TSI GT was £5000 more. The A3 was even more expensive, did not even consider it.

But I did not get mine direct from a dealer, I used a Broker to introduce me to a dealer who actually wanted to sell a car.
 
SEATCUPRA.NET Forum merchandise