Petrol equivalent to current diesel mpg

DUTR

soupdragon10 wrote: »

Just to clarify I am cutting down my number of journeys rather than the distance per journey. As I live in a rural area my shortest journey is at least 6 miles, and usually much longer.

I wanted the information primarily to ensure that when I change my car I get something that isn't worse cost wise. I would take into account insurance, tax etc. but as a 60 year old female with a clean driving record most small/medium sized cars seem similar in these respects.

I am looking to get something 3-5 years old, and haven't ruled out another diesel, but have read somewhere that they are less cost effective if your yearly mileage is under 15000 miles per year.

Not sure the age of your current car, modern cars whether petrol or diesel are more efficient than older cars.
Ive been looking at the screen for my car, I do 6 miles to work, in the morning up to about 3 miles I'm doing about 15mpg by the time I get to work it is on 28.2mpg(busy city driving), coming home this evening, the traffic was heavier and the time I got home it was showing 24mpg, it really depends on your driving style and enviroment.

Paperbird

soupdragon10 wrote: »

Just to clarify I am cutting down my number of journeys rather than the distance per journey. As I live in a rural area my shortest journey is at least 6 miles, and usually much longer.

I wanted the information primarily to ensure that when I change my car I get something that isn't worse cost wise. I would take into account insurance, tax etc. but as a 60 year old female with a clean driving record most small/medium sized cars seem similar in these respects.

I am looking to get something 3-5 years old, and haven't ruled out another diesel, but have read somewhere that they are less cost effective if your yearly mileage is under 15000 miles per year.

Ignore the 15000 miles per year. That was based on buying new cars and selling them after three years. ( The diesel engined car cost more than the petrol version and you deeded to do over 15000 miles per year to save that amount from the higher mpg the diesel gave )
For rural driving avoid a diesel with a DPF.
A neighbour has recently changed from a diesel passat to a small petrol engined car and while they get a similar mpg and slightly lower overall running costs what they have lost in comfort and safety would rule out a similar change for me.

almillar

For rural driving avoid a diesel with a DPF.

Why?
For urban driving, with short runs sure, and even for diesels in general, but why rural?

Gloomendoom

Paperbird wrote: »

For rural driving avoid a diesel with a DPF.

:huh: Another "Why?" here.

We have had a diesel with a DPF for over two years now that gets used almost exclusively for rural driving and it behaves just like any other car, petrol or diesel, that we have owned.

jaydeeuk1

Stoke wrote: »

Does stop start really help with the fuel economy? I remember driving a 3L Lupo I wanted to buy with it's stop start and the seller was never convinced that it really helped if your trip was in an urban area but he thought it might help on a longer run...

Since I bought my car in Sept 2009, the readout reckons the 'stop start' has been active for 23 hours 20 minutes and whatever seconds, so thats 23 hours where the engine switched off when normally it would have been running - a lot of it is stop start for a few seconds here and there, so no sane person (or at least one who values their battery and start motor) would turn ignition off and start back up manually. Thats a lot of petrol saved imo. I live in the sticks in Derbyshire and still get good use out of it.

daveyjp

My car doesn't record stop start activity, but I once did a none scientific test using a watch stop watch to see how often it was activated. Over a typical 5 day working week it was 2 hours.

Paperbird

almillar wrote: »

Why?
For urban driving, with short runs sure, and even for diesels in general, but why rural?

Because they need a minimum RPM for several minutes to do a complete regen. Continually changing gear as in city or rural driving results in an incomplete regen.

Gloomendoom

Paperbird wrote: »

Because they need a minimum RPM for several minutes to do a complete regen. Continually changing gear as in city or rural driving results in an incomplete regen.

Do you actually do much rural driving?

Paperbird

Gloomendoom wrote: »

:huh: Another "Why?" here.

We have had a diesel with a DPF for over two years now that gets used almost exclusively for rural driving and it behaves just like any other car, petrol or diesel, that we have owned.

I've had my diesel with a DPF for over five years and mine also drives just like it should too.

The engine will need around 10 miles to get to the conditions needed to start a regen and as far again to complete it's regen cycle, if at any time during that cycle it no longer meets the required conditions it will continue it's cycle but will not be regenerating at it's required efficiency.
Some makes are more tolerant of it but continued incomplete regens results eventually in a clogged DPF.

I have a relative that uses his diesel ( with a DPF ) for just rural and city driving and he had no problems at all for the first 40,000 miles and then it needed the DPF replacing.