[Closed] Car options - do I want a diesel estate?

I would say a modern diesel would do you fine for that. THey used to sell at a premium which made the maths more complex but after diesel-gate the prices have swung in their favour.

I don't think I'd go for a diesel when you're doing so many short hops.

I've always steered clear of diesels with a similar sort of suggested use as I gathered lots of short journeys were not good for them. Not sure whether that's still the case though.

its the 2-3 miles twice a day that'll kill DPF. barely gets warmed up before you turn it off again.

Doesn't look like enough regular longer journeys to offset it.

First and foremost, a diesel isn't best suited to short trips, they can be a more more efficient than petrol cars, but they do that best at a constant speed. They're okay to drive in town, but older ones can cause a lot of local air quality issues.

So, the school run and shopping run won't be great. The commute is okay and of course on the longer runs it'll be great. That said, comparing my diesel with my wife's petrol, the MPG will be similar at worst, but my diesel is way better most of the time.

Modern diesels with DEF / Adblue and stop-start are far better at being less toxic in town, but I don't think they're as 'less bad' as petrol.

As for running costs, older gen turbo diesels had lots of problems when they got higher mileages, or never taken on a decent run. Injectors leak causing over-fuelling and massive trails of black smoke/soot, DPF clogged, EGR clogged and because of their high torque killed expensive flywheels and clutches, but I guess most of that era have been recycled by now. Modern ones (5 years or less or so) are probally no more complex or prone to giving you massive bills than modern small petrol turbo cars.

I've caused problems in a modern diesel (focus '19 plate) with similar usage. I'd go for petrol or petrol hybrid ideally. I#m trading mine in for a petrol today in fact.

Anyone here run a big petrol estate? Would be interesting to hear real world fuel consumption, my (admittedly never thought of as good) Mondeo estate is bad enough as a diesel

Anyone here run a big petrol estate? Would be interesting to hear real world fuel consumption, my (admittedly never thought of as good) Mondeo estate is bad enough as a diesel

I suppose it depends what you class as big. I had the original Octavia VRS for a while with the ubiquitous VW 1.8T engine, got around 35mpg everywhere.

Now have a Subaru Forester 2.0T and generally get 20 - 25mpg around town, 30ish on long runs.

Oops - can't read.

mashr
Free Member

Anyone here run a big petrol estate? Would be interesting to hear real world fuel consumption, my (admittedly never thought of as good) Mondeo estate is bad enough as a diesel

Not estates but...for the same journeys (2 years on each) i got :

2019 focus 1.5 ecoblue diesel hatch: 47 mpg
2012 octavia vrs 2.0 petrol hatch: 34 mpg

I'm a saddo that tracks fuel with an app not the car's onboard computer, so those are pretty accurate.

However the octavia was 'breathed on' so may have been slightly worse on fuel than the factory map.

By my calculations that's 6500 miles a year maximum.

If the work commute is 15 miles round trip the dpf won't be able to regen in that time, especially not during winter.

So the only chance it might have is your bike trips. You'll likely be running into issues where it'll be trying to do an active regen but can't complete it, which is when you'll run into problems and it'll need a dealer visit.

You're looking at an extra £350 a year based on 6.5k miles a year and going from 45mpg to 33mpg.

I'd say go petrol.

I do a similar style to you, but far less short trips - more 20-50 mile 45min journeys and crucially 5-6 minimum long trips of 150-400+ miles each year.

ta11pau1
Full Member

By my calculations that’s 6500 miles a year maximum.

If the work commute is 15 miles round trip the dpf won’t be able to regen in that time, especially not during winter.

So the only chance it might have is your bike trips. You’ll likely be running into issues where it’ll be trying to do an active regen but can’t complete it, which is when you’ll run into problems and it’ll need a dealer visit.

You’re looking at an extra £350 a year based on 6.5k miles a year and going from 45mpg to 33mpg.

I’d say go petrol.

I do a similar style to you, but far less short trips – more 20-50 mile 45min journeys and crucially 5-6 minimum long trips of 150-400+ miles each year.

Yes exactly. My regular 'long' journey was only 20 miles, and it wasn't enough. Approx once a month my Focus would start saying something like "FILTER FULL - LONG DRIVE TO CLEAN NOW" and I'd have to take it for a long drive (40 mins) onto the motorway. Waste of fuel and my time.

It will cost you more in maintenance of a diesel than in the extra MPG on such short journeys.

I had been doing 20-25k a year in a people carrier, often loaded with 'stuff'. A diesel was a good tool for the job.

I now do 15k a year, in a (large) estate but smaller than the cars I have had before. I would change to petrol if our current car died tomorrow.

IMO, the extra maintenance of a diesel is about even to the extra MPG, particularly when urban MPG in a diesel is so much lower than the headline, appealing figure that you are reading.

You are doing less than 10k per year - perfect for one of the smaller, turbo'd petrols IMO, possibly even a hybrid...

2012 octavia vrs 2.0 petrol hatch: 34 mpg

Sounds about right. 2014 Octavia VRS Petrol estate I would say 35 mpg for me. I can get more like 40 mpg on long journeys. But most long ones the car tends to be fully loaded and often bikes on top, which brings it back down to ~35.

EDIT; I'd also say after my experiences with a modern-ish diesel (2010 2.0 VAG group TDI engine - pre-Adblue, but modern enough to have stop/start etc), I wouldn't touch it for your use. I was only ever doing long journeys, and had no issues with the DFP, but did have expensive issues with EGR cooler. The DMF was also beginning to make very expensive noises when I got rid.

1.8 Avensis petrol, get about 42mpg wherever I go at whatever speed. I had a diesel Peugeot estate and short journeys killed it, ended up replacing the engine. I spent a fair bit of time trying to find a petrol estate that was good on fuel and there didn't seem that many.

When buying my current car, the dealer said to avoid diesels for short journeys. They had lots of diesels available and struggled to find me a petrol version which made me believe them.

I've just switched to a 2l CR-V and I'm finding 25mpg pretty upsetting (maybe 35 on motorway). I wish I had gone hybrid.

My preference would always be for petrol but I ended up in a diesel as looking for large estate cars around 3 years old the petrol choice was minimal without spending significantly more. A Seat Leon was the only car that seemed reasonably common as a petrol but was a bit small.

3.0L Naturally aspirated BMW petrol touring with an auto gearbox gets 35-38 on a run at 65-75, and 26-30 everywhere else.

Newer cars with the 6 and 8 speed autos get better results.

Anyone here run a big petrol estate? Would be interesting to hear real world fuel consumption, my (admittedly never thought of as good) Mondeo estate is bad enough as a diesel

Used to have an MG ZTT with the 2.5 V6, averaged around 25 mpg absolute tops but that was mainly local pottering with a monthly trip to Aberdeen and back.

I know it's not an estate but we had a Honda Civic 1.8 Si for a while and that was very reasonable as a family car. 42-ish mpg average and with a decent sized boot. Depends how much load space you need though.

PHEV all-day is the answer, you may see a diesel hybrid in the not too distant future..

Skoda Superb estate 1.4 petrol. 47mpg on the motorway. 52mpg A roads like Glasgow - Skye. 42mpg last time I checked brim to brim with a mix of short local and longer journeys.

3 liter BMW 335d touring here.

I had the trip computer on for a 4 mile commute to work on Friday. 17mpg.

Normally I ride to work. Fuel is only part of the reason.

The other thing is where can you use a diesel now and in the future. Mine is 2014 and euro 6. It is acceptable in London and the other clean air zones.

Will it be in 5 years? 10? Im not so sure. It depends on how long you keep cars if that's something to take into consideration.

My Berlingo petrol gets 50mpg on a long run. 40's for towns and dual carriageways.

Thanks for the feedback, pretty much confirms what I suspected - that I don't do enough miles to make the diesel work properly. Back to waiting for the right petrol version to come along.
Thanks all.

I've an 07 octavia vrs 2.0 TFSI. About 38mpg "on a run" but typically 20 - 30mpg on shorter trips. Quite hilly around here, plus it's an old car, neither of which help.

I've noticed estates are in short supply so maybe that's an issue as well.
SUVs have been much more fashionable, so 2nd hand they seem to be much more readily available.

Last time I checked Car Giant they had about 100 estates, but 1200 SUVs.

By my calculations that’s 6500 miles a year maximum.

Pretty much bu99er all - fuel economy wouldn't be high on my 'preference' list.

45mpg and £1.50 per litre = £975
30mpg and £1.50 per litre = £1462

About £10 per week difference...

18 plate 2.0l diesel Audi A6 Quattro Auto averaged 41 mpg over 62,000 miles
64 plate 2.0l diesel BMW 320d xDrive Auto averaged 44 mpg over 68,000 miles

Whats peoples distance to trigger a regen on the dpf then? I know there will be variables like ambient air temperature, throttle loading etc
I would have thought 12 plus miles of driving to be enough to get the car to operating temp, then a sustained min or so of 2000rpm or higher and it meets parameters for starting regen
I would imagine switching off mid way or never letting it complete would also be bad.

Went from an 04 2.5l V50 5 pot atmo petrol estate (would not do 40mpg on the motorway, even at truck speeds) to a 66 plate 1.6 Astra CDTi estate that'll break 65mpg sitting around 65mph on motorway runs. It doesn't get used often but the Astra's a peach for long runs. 🙂

I've run a few big estates/SUVs over the years and with a not too dissimilar usage as the OP and I'd go petrol over diesel any day.

The petrols have averaged between 25-35mpg with more modern stuff like Octavia and Mondeo's being towards the top of that range.

Diesels are dirty, shit for local air pollution, sound like tractors, only really get efficient once up to temperature, and don't like short journeys.

Engines themselves are generally pretty reliable, it's all the stuff that's bolted on like turbos, DPFs, EGR valves and the like that tends to break. And diesel engines tend to have more of these extras than petrol engines. And a lot of those extra bits don't like short journeys.

singletrackmind
Full Member

Whats peoples distance to trigger a regen on the dpf then? I know there will be variables like ambient air temperature, throttle loading etc
I would have thought 12 plus miles of driving to be enough to get the car to operating temp, then a sustained min or so of 2000rpm or higher and it meets parameters for starting regen
I would imagine switching off mid way or never letting it complete would also be bad.

Depends on the weather and the speed of the road, but on a 50 limit DC, it takes about 25 minutes in mine at the moment to get the engine to the right temperature and start the regen. Then the regen took 10-15 mins.

In summer it gets up to temp a lot faster though. And also if you've got a nice bit of motorway you can hoof up to 70 on.

Whats peoples distance to trigger a regen on the dpf then? I know there will be variables like ambient air temperature, throttle loading etc

Mine just regens every 200miles, once up to normal engine temp- c 10mins. It then takes 15mins to run the regen cycle. Horrible, stinky and harder to drive if in stop-start town traffic. Fine on a quick A road/ motorway etc.

Whats peoples distance to trigger a regen on the dpf then? I know there will be variables like ambient air temperature, throttle loading etc
I would have thought 12 plus miles of driving to be enough to get the car to operating temp, then a sustained min or so of 2000rpm or higher and it meets parameters for starting regen
I would imagine switching off mid way or never letting it complete would also be bad.

There's generally 2 types of dpf regen, for any regen to happen the engine and exhaust has to be fully up to temperature, the system uses the high exhaust temps to burn off the soot in the filter.

So, passive regen would take place on a normal long drive with the car up to temperature.

An active regen, when this happens the car will stop the stop start function, increase the revs slightly, and if it's occurring when you stop you'll hear the fans stay on for a time after, and the car well be 'hot' even after turning off, as it's trying to increase the exhaust temps to do the dpf regen.

In winter, the car won't even be fully warmed up by 3-4 miles in, so no 12 miles ain't enough. I've done an 11 mile commute from work and the car has been doing an active regen when I got home.

You need a proper run out, 45 mins or more for a passive regen. Less for an active regen but the car still needs to be fully warmed up which when it's 5 degrees outside is going to be only after 5-6 miles.

Also you can't choose when it does an active regen. The car will attempt an active regen if the dpf filter reaches a certain level and other criteria are met, things like fuel light not on, going over 40mph and car oil up to temp.

Ok, that's good to know. 17 mile commute, 30 to 40mins with the majority on nsl dc. Current engine is up to operating temp at start of dc, so 6miles in then its probable regen would start maybe 2 or 3 miles after that and be completed by switch off.

Also I think most cars now will give a warning light and ask you to follow specific instructions to perform a manual dpf regen, basically giving it a hoon on the motorway in 4th gear... Before it tells you to go and see a dealer.

If the fans stay in and it's hot and smelly when you turn the car off that's generally an inturrupted active regen and it'll try again there next time you drive it. Something to be aware of.

Oo,that's interesting - noticed the fan running on the Astra on touchdown occassionally, wondered what it was. 😉

I drive a mixture of school run (2-3 miles twice a day), supermarket (3-5 miles one or twice a week ), work (15 miles when back in office), bike trips (20-100 miles once a fortnight) and holidays (100 miles + once or twice a year).

As others have said, you'll maybe have issues with the DPF, I have a 2015 diesel Passat, I do 8 short trips in the week and then usually longer dual or motorway miles on the weekend which keeps the DPF at bay.

When the car doesnt get used on the weekend and I do a second or third week of short journeys only, the engine will do something that sounds like a jet engine when I turn it off, if I dont do a 4th gear 70mph for 10mins once at temp the DPF light will come on.

You need a proper run out, 45 mins or more for a passive regen. Less for an active regen but the car still needs to be fully warmed up which when it’s 5 degrees outside is going to be only after 5-6 miles.

Right, but you don't need to do a regen every journey. Just every so often when the filter gets full.

In 5 years of driving modern diesels, I've never noticed the car doing a regen. Maybe it's because it was mostly motorway / A road driving.

A 30 min commute is enough to full regen depending on the car, but could be much higher than that. Not all cars will want/need to completely empty the DPF,some will retain soot on the filter to provide enough load to work efficiently. The following articel by a well respected testing house in Poland is a nice easy read

https://iopscience.iop.org/article/10.1088/1755-1315/214/1/012114/pdf

But as others have stated - lots of short journeys will over-load to the point where a manual may be needed, ideally you'r looking for a car that will accumulate and regen over the longest period.

HOWEVER EVERYONE -

DPF's are not only a diesel thing, you now also have GPF's in alot of new gasoline vehicles. It's not thought they will cause as much an issue as the particle size is smaller, but herin is the issue. A DPF is >80% efficient often well upto 90% for some - (diesels are actually very good - so dieselgate hunters you're all a bunch of t055ers). Gasolines on the other hand are ~50-60%, and when cold under load are not efficient in the slightest. Some brands (cant say who) have expereinced school run issues with their little cars over-accumulating soot and manual is then carried out at a garage (the owners are seldom aware of what to do)

If it were me personlly - lets say my car could onyl last 3-400 miles for soot load to full regen, then if i knew within that 300-400 miles i would do at least a 30-40 min journey at a steady ish state, i'd be going diesel..

Depending on your budget it might actually be quite hard to find a decent petrol estate.

In 5 years of driving modern diesels, I’ve never noticed the car doing a regen. Maybe it’s because it was mostly motorway / A road driving.

Same here. 20k miles in 4.5yrs in van with euro6 diesel with all the adblue/DPF stuff and I've never noticed it doing a regen. I avoid local/short driving in it which might help. I also give it a traditional Italian tune-up at least once a journey once warmed - no idea if it helps, but I had sticky turbo vanes on my last van so hopefully using the full rev range helps.

you may see a diesel hybrid in the not too distant future..

diesel hybrids have been around a while, volvo, vw, pug and merc all make one, but they're extremely expensive and so have never sold well. I don't know if any of them are still on sale.