But I would rather have 12 years much better driving experience with my diesel.....!

But I would rather have 12 years much better driving experience with my diesel.....!

Yeah, enjoy your "driving experience" don't worry about about the pedestrians that have to put up with the b***** din of lines of diesel cars - or the children with asthma from the particulates. 'Been saying for 20+ years since the ecoloons forced people to swap pretend pollution(CO2) for real pollution (diesel particulates) that diesel passenger cars should be banned. Not to mention the huge number of diesel spills killing motorcycles. Still, as long as you get your "driving experience" eh?

Just had a quick scan through this report and as usual it is deeply flawed. They don’t factor in depreciation at all, it’s simply the added cost of the diesel cars list price v fuel saving. Some cars depreciate much more slowly with a Diesel engine even today and especially on larger models particularly SUV’s which would skew the figure back down. The Ford Kuga for example is in much lower demand used in thirsty petrol form than the diesel despite it being a good engine.

Quite right, and I bet it doesn't factor in the differences in insurance (not sure about VED), usage patterns, reliability and the cost of parts and servicing, issues to do with DPF cleaning, etc, etc.

I have had the same problems with the Warranty Direct ratings for car relaibility for similar reasons for years - they too, IMHO, are too simple in how they put together their ratings with a distinct lack of comprehensive, reliable data that gives an overall picture. Too many variables, in my view are often missed, often because their don't provide a black and white report that make good headlines to gain clicks/attract business. Sadly reflected across much of the journalism world these days.

Back in 2015 I bought one of the small petrol engined tsi turbo in a 14 month old Superb - mainly because it was so much cheaper to the equivalent diesel at the time, many £1000s infact. I calculated with my mileage it would take over 15 years+ of additional fuel cost to spend more than the saved capital (that is still sat in my bank!). That was presuming 42mpg with the 1.4petrol and 52mpg with the 2.0diesel version. After the purchase this calculation has probably improved further as my real life economy seems to be about 46mpg and there is now a bigger price difference between petrol and diesel.

There have been discussions that small engined turbo petrol cars would be overstressed - doesn't feel like it thus far as mine feels very relaxed on the open road running at about 2000rpm at 60mph. I've now done about 73,000 miles and it hasn't turned to putty as yet and doesn;t really burn any oil.

However fast forward to today would I buy a diesel or a petrol doing my same mileage (15,000.year) - to be honest I'm not sure.

• Nearly new diesel cars seem to be much better value these days thanks to deselgate. Ignoring list prices there seem to be bigger new discounts on diesel cars - well the ones I've been looking at.
• New PPF/OPF/GPF technology being introduced - myself I'd wait for this to bed in!
• DPFs seem to be much better these days - some early implementations were awful.
• HOWEVER even though there is a slight lack in low down tourque (still pretty good on mine though) I'd miss the "zap" of petrol as the revs rise and my petrol is very quiet indeed on my commute

Diesel stench...if you run it with recycled cooking oil the only stench you get is that of chips. Mmmm chips.....

I like your thinking but may I suggest the oil from frying doughnuts? Mmmm, doughnuts. However, you might get pulled over by the police more often than usual. :)

OK tried my same cost spreadsheet with more up to date fuel prices and. updated with my real life MPG. 15,000 miles a year with £1.30 for diesel @ 52mpg and £1.20 for petrol @ 46mpg gives a petrol fuel saving of only £74 year! - would now take 50 years in saved fuel costs to recoup the original extra £3800 I would have spent at the time of purchase.

Fuel.....Price.....Miles price mpg gals litres £year £diff years

diesel £14,500 15000 £1.30 52 288 1313 £1,706 £0

petrol £10,800 15000 £1.20 46 326 1484 £1,780 £74 50

Interesting figures. Only thing I would add is that many diesels are cheaper to buy than petrol equivalents due to diesel Gate. Also larger cars the mpg gap is larger. I had a Seat Leon 1.4 Tsi which regularly got over 50 mpg. So little point in getting a diesel in that type of car. But you look at large 4x4s and you quickly in to the early 20s with petrol and you don’t get the torque you get in a diesel.

This thread prompted me to re-do the calculations I did back in 2015 and the thing that surprised me was the effect the difference in the price of fuel had on the figures. Back in 2015 the price of petrol and diesel was nearly the same. Long term it seems possibly less relevant but I suppose I still have the £3800 still in the bank gathering interest - well not a lot!

I agree that things are now different post dieselgate and there are great deals on diesel cars new and old - it is almost a full reversal compared to when I bought my car, no one wanted a large petrol car then! The Which article is looking at list prices - well I for one won't be paying anywhere near that when I buy my next car, well I do live in Yorkshire!!! If you look at some broker sites prices can be different eg Carfile Skoda Octavia SE the 1.6 diesel ends up nearly the same price as the 1.0 petrol with an 18.5%(approx) discount on the diesel and an 11.5%(approx) on the petrol

Edited by Big John on 29/04/2019 at 21:19

The above is true, but list prices is the only sensible way to do comparisons ( both petrol and diesel cars can be discounted) What would be interesting is to factor in the relatively new expense of add blue ( £15 every fourth tank) and dpf / dual mass flywheel clutch replacement cost and the new london emission charges Dont get me wrong I love Diesels and have owned many of them alongside petrol cars since the citroen zx and xm days in the 1980/90s . Its just anything post 2017 seems to leave me questioning its actual long term viability over petrol.

As I buy cars outright I usually look at the price I'd pay

It's true some petrol cars don't have Dual Mass Flywheel (mine doesn't) but most of the more powerful ones do have them.

As of last year almost all direct injection cars will now be fitted with a particulate filter (PPF,OPF,GPF) so it's another thing to consider.

Myself - I'll probably (we shall see) buy another petrol next as I love the feel of a turbo petrol. They still have pretty good low rev pick up but then really fly as the revs rise. My older generation tsi pulls well from 1500rpm all the way through to 6000rpm. If you take it steady on a long run(er I rarely do!) you can get over 50mpg - not bad for a big barge. I managed 53mpg touring Germany and Austria.

I find modern diesels very tourquey indeed but the useable power is in a narrow rev band. I've also found some of them not as economical as you would have thought. I was rather unimpressed with a hire Mondeo diesel where I only just managed 40mpg.

Edited by Big John on 29/04/2019 at 21:46

How did you factor in the ancillary costs? Extra cost due to increased diesel specific congestion charges/ ulez . Certain Councils are talking about banning diesels from some towns. If that comes to pass you'll have to factor in park and ride fees etc. Like a ratchet these costs are going to increase and wont ever be reduced. Councils need money to pay for their vital work...Hopscotch Collectives etc.

Diesel is going to be killed off in this country by the Salami slice tactic. That way by the time you realise what's happening it'll be too late to protest. I guess you'd call these the political risks.

Lots of interesting points have been made. The biggest factor though is what you pay for the car. Big John mentioned the discount you are getting on diesel cars as they are being deserted by the public. I was given a sizeable discount of mine so it only cost about 500 more than the equivalent petrol (with a discount too) . In my case a diesel has worked out cheaper. I had the petrol version before and it was costing me 20-30 a month more on fuel. (Let’s say 25 average) plus the road tax is 110 cheaper (assuming that continues) . So in a year it was 410 pounds cheaper and by year 2 it has easily paid for itself.

The VED is no longer cheaper for diesels, and only was by a decent margin 8-10 years ago when a greater amount of new petrol cars were port injected and not GDI engines. The difference in CO2 figures for most is far less than it used to be, so many are only (before March 2017 new car VED changes) £10 or so more expensive, since March 2017 all non EV cars are the same at around £140pa.

As I said before, there are many factors that you have to take into account, not just falling new prices - as this will translate into falling used prices as well. If a diesel engined car is used predominantly for short journeys from cold, then most DPF-equipped models will inevitably suffer repeated problems as a result, which can get expensive to fix. Some fair better than others, e.g. the Honda 1.6TD, but as a result, it's likely their prices will remain firmer than those with more issues.

If you use a diesel-engined car for longer distance driving, then a new one will likely be a decent buy if it's well maintained and you only keep it for 3-5 years, negating any issues later in the car's life with the more complex emissions reductions systems. Whilst many newer petrol engined cars now come with PPFs, their design is more robust and also doesn't rely on adblue (which also needs heaters which seem to have reliability issues themsevles) and, due to its higher operating temperature, relies far less on active regens.

It depends on how often you are towing and what your general mileage is in comparison. What I'm surprised at is that no-one seems to consider hiring a diesel car capable of towing if they only need it for 2-3 weeks in total in the year, especially if they don't do much mileage or do mostly urban driving, running a smaller petrol-engined car otherwise.

As regards creeping along at low speed, from what I've seen and driven, the ability of petrol cars varies a LOT - my older Mazda3 petrol is terrible at that and wants to take off in 1st, and probably why the original clutch suddenly went in 6 months of changing jobs to a route where there was a decent amount of jig-jog traffic driving, whereas my old 1.0 Micra (manual), like a TC auto car, could easily creep along at walking pace in 1st and at about 7-10mph in 2nd with no right foot input and without stalling (obviously not on a reasonable hill), as long as it was warmed up. One of the main benfits of running a TC auto - which I swa when I test drove the new version of my car and the CX-3.

TBH I always could've gotten away witha Fiesta sized car for all the year except going on holiday, but I was lucky enough to buy my Mazda just when prices were very low and sourced a 25-30% discount on a new one, which was far cheaper than the smaller Honda Civic 3dr and Jazz which I was looking at. Often getting a supermini everyday car in petrol form is almost as economic to run mpg wise as a mid-sized diesel, especially if its used for shorter urban journeys.

I have owned diesel cars over the last 20 years and never had an problem within any of them and thats in spite of much advice that diesel was not for me as I don't do many miles. There is a lot of misinformation about, even from My current car is 4 1/2 years old and 30K miles and the DPF is in A1 condition.

It's not the total annual mileage that's the problem, but what that consists of: I currently only do 3-5k miles pa, but because that's made up of longer journeys, just less often (no 5 minute or less trips to the shops and back). If I ran a diesel on that usage pattern, I suspect I wouldn't have any issues.

Yours may be like that as well, or the car may be less susceptiable to problems than other diesels on the market, past and present. Your driving style may also lend itself to helping as well. I'm sure the Interweb has many FAQs about PPFs and how they work in general terms - Google is your friend.

How do you know when your DPF is full? I don't recall any non-commercial vehicles having a facility like that. It's a different story if the DPF actively regens every X miles, which means sometimes it's not needed (as they don't fill up uniformly as its dependent on usage type, not miles done) and thus wastes fuel - the problem comes if that limit is reached at the end of an important journey where you can't drive around for another 15 minutes.

To this day, I have no idea why all DPF-equipped vehicles don't come with DPF gauges and a warning, say, within X miles/time of an active regen being required and a countdown to when it will be finished, plus (in the manual) what to do to best facilitate this exercise. Am I right in saying that some (at least) HGVs have such facilities?