Does a diesel make sense?

[gchild]

Thinking about changing to diesel saloon. Not sure what yet, maybe e320 cdi or 530d

I only do about about 7k miles a year, mainly town. Given that, does diesel make sense or settle for equivalent petrol model and stomach the mpg difference?

 

[LTD]

Personally, I don't think you'll do the mileage to warrant the mpg difference.

If you are buying used, get a large engined petrol version. The extra toys and comfort factor will outweigh the mpg savings.

As always, it's your decision - drive both types and make your own mind up.

 

[corned]

The cost of the fuel will be a very small factor in this decision, given the mileage covered.

The better residual prospects of a diesel, however, might sway your decision...

 

[ace571]

Personally, I don't think you'll do the mileage to warrant the mpg difference.

If you are buying used, get a large engined petrol version. The extra toys and comfort factor will outweigh the mpg savings.

As always, it's your decision - drive both types and make your own mind up.

+1

Take a look at the petrol powered equivalents and see if they are available for less than the diesel version (likely)

To offset the price difference of a diesel you'll probably need to be doing more than 7k a year.

Don't forget diesel is 8-12p more a litre at the moment!

 

[wemorgan]

Difficult question to answer with true impartiality. I suspect most diesel owners will vote for the diesel option and vice versa.

The acid test will be when you test drive both options and make your own conclusion.

For me, I prefer the greater low rpm torque for town driving. Give me a high rpm petrol for B-road runs and track days

 

[Deleted member 37751]

How much are you spending and how long do you intend to keep the car?

 

[st4]

Depends. Diesel might cost 10% more BT the car will use 30% less fuel. If saving a fifth or more if your fuel bill is important look at the diesel. If you couldn't care less dont unless you like the diesel car anyway.

In this segment finding a diesel motor will be easier as 80-90% of used ones are diesels.

Given the quality of diesel engine these days it's not a poor relation but for responsiveness and aural pleasure the petrols do win hands down.

 

[A210AMG]

Hello

I do about the same and NEVER thought I would drive a diesal...

However having had big engined petrol cars I still get fed up of watching the fuel guage go down so quick and costing £100 plus to fill up. Almost working out journeys by the cost of fuel in my head...not good.

Now we have 2 diesal cars, both do over 40mpg wifes closer to 50mpg, even towing and loaded up mine does 26 - 28mpg a dream away with a petrol.

It means now we just drive anywhere we want and I don't think about the costs. In the real world it probably as quick as most petrols also like for like. I can get 700 miles from a range and it seems to have the same fuel in for ages.

Yes petrols cheaper but its a knock on when you sell it, petrols cheaper to buy but you use more....

I'm happy swapping and now I look forward to drives and want to try and break 50mpg

 

[LTD]

Does the DPF become a factor with such short journeys ?

 

[Dieselman]

Does the DPF become a factor with such short journeys ?

Definitely, the engine oil will become polluted with diesel and the DPF will clog.

 

[st4]

Does the DPF become a factor with such short journeys ?

Only if the car has one...

If its 7k miles a year and a few long journeys no. If its lots of small journeys a big issue. Part of owning a diesel means you must plant it once a week to clear her out. It's big fun

 

[LTD]

If its 7k miles a year and a few long journeys no.

Never seen many long journeys 'in town' as the OP suggests will be the primary running.

Does 'booting' a diesel now and again clean out the DPF ?

 

[A210AMG]

How do you know if your car has one?

I try to use mine on longer runs and if needs be give it some beans every now and again on 'the' run...

 

[corned]

How do you know if your car has one?

By all accounts, now and again it goes very sluggish, uses quite a bit of fuel, and stinks of burnt rubber. This is the DPF 'regenerating'.

Personally, I think Dr Who made a better job of it...

 

[wemorgan]

Motoring becomes a bind once you starting worrying about whether your journey is good for the DPF or not, or any other latest car technology addition. The OP needs to buy the car that's fit for purpose (dreadfully over used phrase, sorry), whether that's petrol or diesel.

 

[ace571]

How do you know if your car has one?

General rule of thumb, downturned exhaust pipe - no DPF.
Straight, open, petrol type tailpipe - has DPF.

 

[st4]

Never seen many long journeys 'in town' as the OP suggests will be the primary running.

Does 'booting' a diesel now and again clean out the DPF ?

Booting the car decokes it. Any slightly remaining residue gets combusted. Exhausts can get deposits not far off soot left in them. A good blasts clears it.

A DPF and it's regeneration are an entirely separate issue. A good constant run will allow the engine to facilitate particulate burn off which at town speeds isn't possible. A DPF is a fuel burning device and needs a level of power output to get it to work.

 

[st4]

General rule of thumb, downturned exhaust pipe - no DPF.
Straight, open, petrol type tailpipe - has DPF.

Not really. I don't have a DPF and I have two proud open straight pipes. Most engines that are EU5 and above will require a DPF.

When a DPF is fitted the car will make a different sound from time to time with a corresponding rise in engine speed in either a gear or idling.

 

[blue gnome123]

Interesting question. The negatives of having a big diesel in town is that you may have problems with DPF (my 2008 e320cdi doesn't have one) and with short journeys a big diesel will likely rarely get up to temp.

Costs wise at 7K per year round town the difference in fuel costs will be less (35mpg diesel=~£1200, 30mpg petrol=~£1300) than other issues like servicing (more for a diesel), tax, loan repayments and insurance. Residuals are the biggest factor in your costs.

A petrol will be cheaper to buy and have lower residuals (you then have to factor in how long you will keep the car to this calc). A smaller power petrol might be the right car for the job? 528i or e200.

We have a Honda Accord petrol that we use for shorter journeys and the e320cdi for longer journeys.

 

[mattc]

Nat's e320CDi is averaging 17.9mpg because she drives 4 miles a day in the school run.
A petrol would probably offer something similar but worse annual tax duty.
she loves the low down torque for use around town. it does get a run out at the weekends.