I recently bought a diesel passat which seems so far to have been a sensible choice.
It's a 2015, it meets Euro 6 so no charges for cities, but it also doesn't have an AdBlue system so nothing to worry about breaking down there. A quick check of the DPF health showed it only has a 52% ash build up so it should outlast the rest of the car given it's taken 113k miles to half fill it. Cleaning the ash out isn't really complicated or expensive these days anyway.
It gets run for both short stop start journeys around town and occasional long runs for work once a week and touch wood hasn't had any emissions related issues yet. You can feel when it is doing a regen as the idle rises to 1,000rpm and sometimes you interrupt it when you stop, no problem it just resumes it next time you turn it on. Doesn't seem to dump any fuel into the oil like some engines do when this happens as the level hasn't risen in 6,000 miles.
With my mixed use it gets an average 52mpg and diesel costs the same per litre as petrol now, so it's costing me a lot less in fuel than the petrol Seat it replaced which never managed to average more than 37mpg.
a decent slowing/braking event event at motorway speeds in our Zoe can add several miles to the guessometer.
it doesn't actually add that much range though. If you imagine coasting to a halt at 70mph - its pretty unlikely you'd get "several" miles - and that would be the case if you had 100% recouperation during regen.
Dunno – its a 2019 diesel Merc E Class
I would guess the dealer is brimming it at service time. the tank is a pretty big 25l - I suspect they've done that to avoid user inconvinience. For comparison, our zafira has a 5l tank (I think) and it needs more every few months - maybe 2l per 1000miles consumption.
A quick check of the DPF health showed it only has a 52% ash build up so it should outlast the rest of the car given it’s taken 113k miles to half fill it.
My Mercedes was on 12% at 82k miles. 52% sounds like a lot. Possible that someone's used the wrong oil at some point.
Doesn’t seem to dump any fuel into the oil like some engines do when this happens as the level hasn’t risen in 6,000 miles.
It can burn the oil as much as its letting fuel into it, so the level can stay the same.
it doesn’t actually add that much range though. If you imagine coasting to a halt at 70mph – its pretty unlikely you’d get “several” miles – and that would be the case if you had 100% recouperation during regen.
My EV had a little gague showing you how many miles it recovered each time you'd brake. Coming off a motorway from 70 would add about 3/8 of a mile. The only place I ever managed to gain a mile was going down Dinmore hill on the A49 which is about 3/4 mile of 1:10
A quick check of the DPF health showed it only has a 52% ash build up so it should outlast the rest of the car given it’s taken 113k miles to half fill it.
How is this check done?
What puts me off another diesel is the oft quoted 'average' lifespan of 100k miles for a DPF.
Our 10 yr old Polo ended up asking for a regen really frequently (yellow dash warning light), so I assumed that the DPF was getting full up with ash.
If there is a way of knowing what the current DPF health is fairly easily and changing a DPF is actually not that expensive a deal these days, then I might reconsider for our next used car.
For my particular use it’s financially better to run two vehicles...I consume a lot less fossil fuel by splitting my driving between a van (33mpg) and small diesel car (60mpg).
The saving in fuel by not using the van 100% of the time more than covers the running costs for the second vehicle (fuel, VED, MOT, consumables, insurance, servicing), with a comfortable surplus towards deprecation and unknowns.
Obviously I have no idea about your financial arrangement, but surely just looking at running costs doesn't consider the cost of buying the second car (or failing to sell the second car)...?
A 1.5 dtci grand Cmax has spcome up near us.
We have never had a diesel before , will a 4 mile stop start commute each way be bad for it?
Every other weekend it will have a 130 miles round trip on the motorway.
zippykona
A 1.5 dtci grand Cmax has spcome up near us.
We have never had a diesel before , will a 4 mile stop start commute each way be bad for it?
Every other weekend it will have a 130 miles round trip on the motorway.
It should be fine.
I think I said it earlier in the thread, but probably easier to repeat than find it.....my Wife commuted for ~4 years or so to her previous job in a 2 litre diesel Ibiza and that was <2 miles away. It presented no issues.
A regular 130 mile round trip should blow the cobwebs away.
The only thing I would say to caveat this, is that several years ago the local garage I use mentioned that we would be better off running branded fuel in our cars, rather than supermarket fuel. He said that whenever he sees dpf & EGR valve issues with diesel cars, most times when asked the driver says they predominantly use supermarket fuels.
So, that's what I try to do - run branded fuel where possible. This comes up on here every now & again and can be a topic of great debate/argument over whether there is any difference. For me, it seems like a sensible precaution to take & having taken my car to this mechanic for ~20 years now, I trust his advice.
Our 10 yr old Polo ended up asking for a regen really frequently (yellow dash warning light), so I assumed that the DPF was getting full up with ash.
Not necessarily, it could be another fault that has caused the engine to smoke and is filling up the DPF. The car knows the ash load and the current soot load as different values and they are both accessible using OBD2 readers Is expect.
Obviously I have no idea about your financial arrangement, but surely just looking at running costs doesn’t consider the cost of buying the second car
We borrowed the money, and the reduced fuel cost can be offset against the loan repayments and insurance.
Re branded v supermarket fuel. Surely as there are only a few refineries in the UK, all the diesel is coming from them and therefore the same to all end retailers, ie standard or posh with some additives.
Maybe mostly supermarket fuel users are mostly running about locally hence filling up when shopping and the high mileage bunch are filling up anywhere so use more branded fuel..... dunno? That might fit the pattern of dpf/egr issues.
Obviously I have no idea about your financial arrangement, but surely just looking at running costs doesn’t consider the cost of buying the second car (or failing to sell the second car)…?
Correct that it doesn't consider the second vehicle cost, but I'm (very) lucky that I own both vehicles outright: it wouldn't make financial sense if I had lease or loan payments on top. One downside is tying up funds in the second vehicle though. I appreciate it's a rather narrow set of circumstances that make this a plausible situation.
zippykona
A 1.5 dtci grand Cmax has spcome up near us.
We have never had a diesel before , will a 4 mile stop start commute each way be bad for it?
Every other weekend it will have a 130 miles round trip on the motorway.
Another +1 to 'it'll be fine' for pretty much what @stumpy01 says. Issue with any used vehicle is not knowing what previous use it's had - you won't know (for sure) if previous owner has done exclusively town use with zero long journeys. Same can be said for any used purchase though.
The only thing I would say to caveat this, is that several years ago the local garage I use mentioned that we would be better off running branded fuel in our cars, rather than supermarket fuel.
We found that both the Galaxy and V70 'preferred' branded fuel from MPG point of view, and I don't know about the rest of the engine. I also a few times year filled up with the premium fuel before a long trip to help it 'clean out'.
Current 1.4tsi does get better mpg on Shell - and currently our local Shell garage is same price as Tesco.
He said that whenever he sees dpf & EGR valve issues with diesel cars, most times when asked the driver says they predominantly use supermarket fuels.
It could be a statistical anomaly though because most people use supermarket fuels most of the time, so it is highly likely that whoever comes in with a DPF or EGR issue they will have done that. You would need to gather two samples of people, those who use branded and those who use supermarket fuels, and assess incidence of problems in each group.
molgrips
It could be a statistical anomaly though because most people use supermarket fuels most of the time, so it is highly likely that whoever comes in with a DPF or EGR issue they will have done that. You would need to gather two samples of people, those who use branded and those who use supermarket fuels, and assess incidence of problems in each group.
Yeah, exactly. It could be.....or it could not be. I have no way of verifying this myself.
So for the few pence/litre extra it might cost I am happy to use branded fuel wherever possible.
I just wanted to make the point that it might be a factor why we have so far seen no engine issues despite a daily short commute with a diesel engine, in relation to zippykona's question about usage case for the car he's potentially buying.
We had a new Toyota Corrola Estate PHEV as a hire car in Sicily last year. It averaged 69.9mpg over 1200 miles with 4 people in it and the Aircon running all the time.
I would be buying a small car with a big diesel engine. We have a BMW 1 series with the 2l turbo diesel engine. Its plenty quick enough, averages between 50 and 60mpg, it does 48mpg with the full bike carrier hanging off the tow bar. At the same time its eco. We bought it second hand, so no manufacturing pollution, and only attracts £20 year in VED its deemed to be so green.
My Mercedes was on 12% at 82k miles. 52% sounds like a lot. Possible that someone’s used the wrong oil at some point.
doesn't the ash get burned off periodically anyway, so the amount you show on your reading is like looking at the amount of fuel in your tank at 80,000 miles and basing the fuel economy on that?
doesn’t the ash get burned off periodically
As understand it, the soot is what is burned off during a regen. The ash is left over from traces of engine oil that have been burned in the engine, which is why if you have a DPF you need low-ash oil. It cannot be removed because it's the non-combustible residue - that's why they call it ash.
I notice that a 17 Cmax has £35 tax and an 18 £180.
Are there plans to make pre 18 diesels the same price as 18s?
Are there plans to make pre 18 diesels the same price as 18s?
No. The model changed because more cars were less polluting. Our car is £20, later of the same were the same flat payment you're seeing.
If anything they may change earlier cars back to a flat model
I have a 2l Turbo petrol car and a 1.6 turbo diesel van. The shortest journey I'll ever do (which is rare as I normally cycle) is a 20 mile round trip. I'll normally do 70 miles each way to work, spread over several days, both minor A and B roads, and a 70 mile round trip to the beach on minor roads.
Petrol 33mpg. Diesel 36mpg.
My adblue system failed. Basically between the manufacturer and various technicians we never solved the problem, but drained my wallet of 2k. In the end, the system was disabled for £200 by a mobile technician.
I would always get a petrol, if that's an option on your choice of vehicle. I would avoid hybrid looking at your mileage, you'll suffer mpg-wise.
If buying a diesel, I'd delete the adblue the day the warranty ran out.
If buying a diesel, I’d delete the adblue the day the warranty ran out.
But do you not care at least trying to do your best for the environment ?
Did you not read all his post?
If buying a diesel, I’d delete the adblue the day the warranty ran out.
Don't. It makes your car run better, see above. Sure, it failed on your car but anything can fail. That's modern cars for you, and emissions control equipment is the price of a better world.
<p style="text-align: left;">We bought it second hand, so no manufacturing pollution</p>
Slightly generous here. The car was still manufactured, and someone presumably sold that car to buy a new one - which was also manufactured.
Yeah, if you didn't buy used cars then their value would be lower which means someone woudl be more reluctant to buy a new one - possibly.
A rep came in moaning that she will have to pay ulez even though her diesel car is only £35 tax.
How does that work?
A rep came in moaning that she will have to pay ulez even though her diesel car is only £35 tax.
How does that work?
Zero tax & zero ULEZ for my dirty diesel 🤔
Upto end march 2017 ved was based on CO2 emissions, so low CO2 = low VED, but earlier than about Sept 2015 & it won't meet ULEZ limits on NOX at a guess?
Adblue systems aren't inherently bad - there are lots of trucks with them still working perfectly with many many hundreds of thousands of miles on them. And all manufacturers have put a lot of work into making them generally reliable - SCR is a much better idea than the cludge of EGR to reduce NOx.
On a different note, my son has been looking for a first vehicle, and there seem to be a lot of good, well priced Euro 4 and 5 diesels available in the SE (making a buying trip worthwhile). Small dealers are keeping and selling-on good but old part-ex cars that have only been changed due to ULEZ (so haven't had WBAC and auction slices added to the window price like a lot of 2nd hand sales stock). It would be environmentally bad to prematurely scrap otherwise functional vehicles so guess it is acceptable to use them up in areas less troubled by local air quality.
But do you not care at least trying to do your best for the environment ?
Erm, what on earth?? I spent 2k trying to do just that! Renault HQ France couldn't figure it out. My van was coming up to an MoT and it was basically a write-off, unless I deleted it.
It's such a common failure, there's a whole industry in deleting them. It's a fudge to pass NOx levels in towns. As I do near zero urban driving my deleted system has limited impact on the environment.
Don’t. It makes your car run better, see above.
Not necessarily so...my van is returning better mpg and running sweetly now the adblue has been deleted..... I'll either get a petrol van next (Nissan Townstar LWB) or another Trafic and delete the adblue at 3 years old + 1 day. I can't afford not to... the cost of these systems is prohibitive...No guilt felt on my part whatsoever!
An interesting read.
We dropped the 2nd car for an electric moped as we're out in the sticks so an ebike wasn't practical enough (tennis/golf 20 mile round trip, weekly trip into work 30 miles). It's worked well so far in case that's less of a jump for the OP.
Our only car, a 2016 Outlander PHEV, works well as the single car as it's essentially an EV during the week and then generally full to the gunnels with bikes/dump runs/IKEA/camping stuff at the w/e.
Yes, I'd like the mpg to be above 40 on petrol alone but 35 is more likely. And yes, the once high score of 30 mile range is now more like 20. But with a 4yr old scrambling all over it we're going to sweat this asset until he's driving! 🙂
It’s a fudge to pass NOx levels in towns. As I do near zero urban driving my deleted system has limited impact on the environment.
Just to correct this - SCR is most effective outside urban driving as it needs exhaust temperature to work - so you are definitely emitting WAY more NOx without an SCR.
SCR systems are categorically not inherently unreliable - I engineer these things as a day job and have never seen a whole system fail to the point it was impossible to know the cause. They are relatively simple systems. The main things that can go wrong are deposit buildup - can be cleaned off or just disappear during a DPF regen - or NOx sensor failure (most common failure I’d say).
Removing an SCR also won’t increase performance in any way - there is nothing they do that reduces performance in the first place and -as mentioned- allow much less EGR to be used = better mpg = lower CO2 = less soot = less DPF regens = less chance of DPF blocking.
They aren’t perfect, but they are very very good - near 100% conversion efficiency in extra-urban and highway conditions.
That Honda mentioned above uses an LNT - this stores Nox and then purges it by running rich for a while. I cannot make this as an absolute statement, but it’s likely over a witch the LNT won’t need to purge frequently with the result of great NOx and low CO2. On the road at high nox conditions, that might be a very different story. LNTs have basically been ditched by the industry even though they are a lot cheaper than SCRs because they are nowhere near as effective in real world conditions.
The amount of AdBlue used depends entirely on how you drive the car. Trundling down the motorway at 70mph will use almost none. Doing 90+ will drain the tank within 5000 miles.
My old Volvo V90 used to get about 15,000 miles to a tank of wee with mostly motorway driving at lower speeds.
I engineer these things as a day job and have never seen a whole system fail to the point it was impossible to know the cause.
I've seen a (small) handful. Less than 10. But then, i used to deal with warranty on emissions systems...
At the point i stopped dealing with them, we had around a million adblue/Eolys/SCR equipped cars in service. Faults were generally easy to diagnose and fix.
Generally those that were impossible to fix (other than rip out and replace) had been run with a fault for 10s of thousands of miles.
It’s a fudge to pass NOx levels in towns
It's not a fudge. It's the best way to solve the problem. By deleting it you are not solving the problem. I appreciate it's an issue, but we are where we are.
the cost of these systems is prohibitive
As above, it's not an inherent cost in the system. You were just unlucky. I also spent £2k trying to get my engine ECU working properly after a shit mechanic screwed it up, but that doesn't mean engine ECUs are 'prohibitively expensive'. They are just part of a modern car, and a part from which we all benefit.
In the old days motoring was about regularly replacing lots of stuff due to wear, then there was a period of really long lasting cars, but now we have cars that are generally much more reliable but you have a low chance of a really expensive bill. C'est la vie. Go electric next time. I firmly believe that the chance of a battery issue is going to be far less than something going wrong with all the intricate engineering under an ICE bonnet.
“Generally those that were impossible to fix (other than rip out and replace) had been run with a fault for 10s of thousands of miles.”
Mine had done no more than 250 miles after the warning on each of the three(!) failures.
All components had been replaced inc Adblue module, hence why Renault France couldn’t figure it out.
Hopefully there will be a clean alternative before too long, but EV vans don’t seem to be much use at the moment, so next one will be a new ICE vehicle, with manufacturers warranty…
Still looking. Octavia estate is favourite.
What are the 1.0 TSI engines like in one? I imagine pretty toothless, which is fine really, but how would it fare on a motorway cruise?
What are the 1.0 TSI engines like in one? I imagine pretty toothless
You don't need to imagine, you can look up specs. 115bhp and 200nm torque at 2000rpm. That would be fine on the motorway. It may be 1.0l but it's turbocharged.
What are the 1.0 TSI engines like in one?
I drove one as a test drive. Around town and two up it's fine
I sat in one this weekend up the A9 following our Leon 1.4tsi. Both loaded similarly with bikes and two people and luggage. Our Leon managed 10mpg more due to the more powerful engine.
Our Leon managed 10mpg more due to the
more powerful engine.lots of factors, unrelated to engine power
in the same car, under test conditions, the 1.0 is 20% more efficient. This is unsuprising due to its lower weight and 25% less frictional losses (due to fewer cylinders). Under the driving conditions you describe there's unlikely to have been a need to drive in lower gears for significant proportions of time so the difference in MPG would likely be a result of driving style, tyres, weights, differing aerodynamics, mis-reporting by the onboard computer or simply a fault with one of the cars.
115hp in an estate is not great imo. Our previous golf was that power but diesel. It was ok but sluggish (think when you want to pull into a gap), especially when loaded. The 1.0l petrol should be lighter and I think it's 5hp more which may make enough of a difference. Around 150hp makes a more pleasant and less stressful drive.
