How much can a diesel save you over petrol equivalent?
 

I've read that 15k a year is the point at which a diesel starts becoming financially beneficial. Is there a simple formula (taking into account fuel costs, servicing, initial outlay, etc) for working out the percentage that a diesel will be cheaper than the equivalent petrol car? eg. VW Golf TDI vs VW Golf FSI.

I know any 'magic' formula is only going to give a rough idea, but I'm lazy :) and don't fancy sitting down with a calculator and a copy of WhatCar for hours on end to work out exact numbers for specific models.

Just look at the pence per mile.

Even at 15k/annum you'll need to keep the car a few years to make any saving if they cost more than a petrol. Buy a secondhand oil burner and it makes much more sense.

F

Diesels tend to sell for more second hand than their petrol equivelants, so you'd need to take that into account too.

I had a Passat TDI, got over 600 miles to a tank (£50 to fill it)
Was only the 100bhp one but they are quite quick due to better torque on the oil burners.
A TDI golf would probably be quicker than a FSI one too ;)

You need to look at pence per mile - that will give you an idea of what any car will cost over 36k and 3 years. Diesels will sell better in a dying market, and if you are doing more than 10-12k / year, people will accept a higher millage diesel. And 9 times out of 10 the diesel is quicker and more flexible in the real world than the petrol. The downsides are the initial purchase price, noisy / smokey / smelly diesel, having to put smelly fuel in and engines are noticibly heavier and effect handling.

The FSI is menat to be a cracking engine though in the new veedubs, so try both and see what you think.

Depends on the model and manufacturer. Diesel will hold it's value better on most models and a 2.0 140bhp diesel is going to feel far more powerfull than a 2.0 petrol as it will have far more torque.

Servicing isn't so much of an issue now, infact VAG diesels on variable servicing go upto 30k miles while the petol only has a 20k mile limit.

If you are thinking of increasing the power of your car most turbo diesels can be increased by around 30% for a few hundred quid while a N/A petrol will cost a fortune to get the same increase.

From a pure finance point of view I think you would have to pick two models and compare them, there isn't really an easy calc milage figure that you can use.

Even if the diesel works out more you may find it's a far better car to own and drive. Just try a Mondeo 2.0 petrol against a Mondeo TDCi 128 or a Passat 2.0 petrol against a Passat PD130 to see what I mean.

Cheers
Lee

From my experience I'm saving about £200 per month changing from a petrol to a diesel. That's purely fuel cost. Nothing else taken into account like insurance etc. Can't fault that as a saving!

OK, so that is going from an E39 M5 to a 330d, but even from a 330i to a 330d you'd get 10-15 miles per gallon more which equates to about 120-180 miles per tank. That's about £12 every time you fill up, so monthly about £65. Still not a bad saving.

My 330d is "worth" a couple of grand more than a 330i of the came age and spec, but then it was a grand more in the first place. :)

You pays yer money you takes yer choice. ;) I loved the sound of my M5, and the BM petrol straight six is fantastic. Yes, petrol engines will always always sound better than diesels, but I'll take the diesel for the time being.

Matt

I changed from Volvo T4 to Passat PD130 sport. I do 15K miles a year. Passat has averaged a true 48mpg (real, not trip computer figures) over 2.5 years compared with an average of under 30 for the T4.

That's £700 per year saving. Then road tax is cheaper by £40, insurance about £100.

It's a company car so the initial cost wasn't an issue for me but the Passat saves £40 per month on benefit-in-kind tax too. As I pay for my own fuel it's a big overall saving which has already paid for buying & running my classic bike :)

I can easily get 480 miles out of my Fabia Vrs when driving conservatively. My old Fiesta 1.25 petrol would get me about 275 miles. Cost to fill up

Fabia 1.9 vRS £35 ~ 480 miles
Fiesta 1.25 zetec £28 ~ 275 miles

So considering the Fiesta is/was an economic car to run, the Fabia is just bloody fantastic!!! :)

Of course the only downside is that you are so tempted to enjoy yourself in the Fabia that maintaining the conservative driving style can prove too much, so instead its big :D for Fiesta type running costs.

Thanks guys, I did test drive a new VW Golf 140TDi last year and was well impressed, not only with the engine but by the ride/handling too. Haven't tried an FSI version but having got used to the scoob's power delivery I think I'd rather drive a diesel than a petrol.

Fabia leaves me cold TBH, not because it's a Skoda but because it looks so frumpy. Seat Ibiza Cupra TDi looks too chavved-up to start with. Leon Cupra TDi seems to fit the bill (if a bit dated), same goes for the MKIV Golf. Old Focus TDCi Sport is possible I guess (yawn), new Focus TDCi is niceish but I don't want to buy new again and get spanked on the depreciation like I did with the scoob :(

Ultimately it's going to be a step down either way so I can't get too excited about it. In fact I'm struggling to get my head around spending a not inconsiderable lump of cash on a car that doesn't excite me at all. The day I pulled up outside the Subaru dealer and saw my spangly new WRX parked up was awesome, and I've loved owning and driving it since. Probably the ideal car for me and my lifestyle, apart from the running costs!

I know as soon as I sell the scoob I'll regret it, but hey c'est la vie.... :)

Totally here what your saying

I did the same 3 months ago, swapped the Scoob for a Golf tdi 150. Not a bad car but not a patch on the enjoyment of driving the Scoob. Once you get the tdi going you can still overtake almost as easy as the Scoob, well its easy for a couple of cars but when its a 3 or 4 abd it runs out of oomph at a few thousand revs and you start grabbing for gears part way round its not the best. The Scoob you would just let it go to near the red bit. The figures and experience might say its as quick as a Scoob but it certainly dont feel that way.

The cash side is the compensation though. I've gone from £50 a week to £50 a fortnight in fuel alone thats a mix of rush hour town driving and country road. Insurance halved too, plus its on variable servicing so should be cheaper.

As mentioned, these cars arent cheap to buy even used, but that proves residuals are pretty good particularly on the German marks. Losing 10grand in 3 years wasnt funny with the Subaru.

Trouble is 3 months in and I've started to forget the running costs and I'm starting to think another couple hundred quid a month is going to be worth it for the smiles :) the Scoob brings.

Is the handling as bad & soggy as some have suggested? The MKV Golf I tried was excellent in that department. I think I could handle a slower car if it handles well through the twisties ;)

My thoughts on the models I've driven.
If you want a car that handles nice with plenty of feel then forget the MkIV Golf, Octavia Mk1 or the Leon, even the sporty models lack steering feel and involvement. The Focus drives excellent but the TDCi 115 is a bit week.
The MkV Golf and Octavia Mk2 are excellent but still expensive second hand, the new Leon looks good when it comes out. The new Focus is an excellent drive but I haven't driven a 2.0TDCi yet only a 1.6TDCi which felt a tad underpowered.
I went for the Octavia as boot space is important, they are better value for money, dealers are excellent and if JD Power is anything to go by I shouldn't have too many problems.

As ever go and try them for yourself, you pays yer money etc etc.

Cheers
Lee

New Focus will depreciate like nothing else even with a 20% discount on the Focus I felt the Fabia was the better choice, I haven't regretted my decision at all. :)

I bought a Saab 9-3 petrol LPT, for 4 grand on a Y plate recently, the diesels were all 2 grand plus dearer, that buys a lot of petrol, it does 30 mpg anyway so whats the point of a diesel ?

Saying that wee have a Sharan Diesel, wouldnt entertain a petrol one (well perhaps the V6 but I aint stupid), big cars need torque to even move, drove a 2.0 petrol and it was feeble, 46 mpg on a run cant be argued with.

So it depends on what car and its intended purpose.

We have a Fiesta 1.4 duratorque diesel - whoever drives the most miles on any day takes this and the scoob with the other driver. With good driving technique we get 500miles from £30 diesel with the fiesta, doing upto 1000 miles per week - the corsa we had before it gave us 300mile from £30. that's a saving of £1500 for the 42000 miles we have done in the fiesta over 2 years. we purchased the fiesta on 0% finance too, saving a few quid there as well. If we want to go out for a bit of fun - take the scoob.