When does diesel become more economical

Eoin

Hi Folks,

I realise there is no definitive answer to this as each car varies, but I was wondering roughly how many miles you need to be doing a week before a diesel engine is more economical than a petrol engine.

In the next few months I am moving house, and my commute will go from about 6 miles a day to over 40 miles per day. I currently drive an 1600cc Alfa 156. It is quite thirsty for a 1.6 as I get about 350 miles out of 50 euro (well, probably less mileage than that at the moment, due to the current petrol prices).

So, I am wondering whether it makes sense to:

1) Hold on to the Alfa (most likely)

2) Change to a diesel car

3) Change to a smaller petrol engine (least preferred as I want a comfy car for the commute).

thanks in advance,

Eoin

prospect

All depends on the cars individual mpg rating, and they type of commute, etc. Also, alot depends on the difference in price between petrol and diesel, going into the future, which is anybodies guess.

I travel about 45 miles a day, and I am fed up to the teeth putting petrol in the car. I am changing in january, and will deffo be getting a diesel. Not only for economy, but I just prefer turbo diesel engines, esp the 1.9Jtd..

Prob not the answer you wanted, but my tuppence...

css

It all comes down to comparing the costs per mile. The more miles you do, the more economical diesels become. Before diesels had higher road tax, but with the newer ones (more depreciation if bought new) you won't get the road tax.

My advice would be to buy something 3-4 years old if you wanted a diesel. Bear in mind the diesel needs more regular maintenance, not much of a problem if you can DIY it though.

Companies usually use the 25k mark as a general guide, but for everyone it's different. It's basically down to comparing costs.. Doing 40 miles a day wouldn't warrant a diesel in my books, but it all depends on your personal choices!

11811

well considering the price of diesel right now i dont think the difference is as great as it used to be!I drive a diesel myself and get between 400 to 550 miles out of a 60 litre tank depending on types of journeys,average would be bout 450.so you would get maybe 100 miles more out of a tank for 60 euros (ish).the only bother is u have to service diesel engines more often,every 5000 miles on average so this side of things works out a bit dearer!

Eoin

css wrote:

Companies usually use the 25k mark as a general guide, but for everyone it's different. It's basically down to comparing costs.. Doing 40 miles a day wouldn't warrant a diesel in my books, but it all depends on your personal choices!

oops, just did the figures and only realised now that 40-50 miles a day works out as 10-12,000 miles a year, which is barely the national average. I certainly didn't think that the average person drives 50 miles a day...

Sorry for the stupid question, but taking an average diesel and petrol car - which is more efficient in traffic?

css

eoin_s wrote:

Sorry for the stupid question, but taking an average diesel and petrol car - which is more efficient in traffic?

Diesel by a mile..

prospect

Cuddleworthy wrote:

u have to service diesel engines more often,every 5000 miles on average so this side of things works out a bit dearer!

Are you sure about that? :eek:
I had a diesel Renault Van, (which incidently ran perfectly, and completely problem free), and it had service intervals of 18,000 miles.

Eoin

css wrote:

Diesel by a mile..

hmm, that might make it worth my while to switch then as I can envisage a combination of motorway and city driving...

Thanks for the help...

What would people recommend around the 10K mark?

Eoin

css

eoin_s wrote:

hmm, that might make it worth my while to switch then as I can envisage a combination of motorway and city driving...

Thanks for the help...

What would people recommend around the 10K mark?

Eoin

Now you're opening a can of worms. Everyone will recommend different cars, my advice for a commuter, is get ABS and AC, most important features to have! After that there's loads of different choices!

alias no.9

Cuddleworthy wrote:

I drive a diesel myself and get between 400 to 550 miles out of a 60 litre tank depending on types of journeys,average would be bout 450.

I really hope you're driving a 530D or similar, 400 to 550 miles from a 60 litre tank works out at between 30mpg and 41 mpg.

DirkVoodoo

Well Diesel engines generally cost more, are heavier and in the last 10 years have evolved a lot more than the petrol engine. This also means that the sophisticated engine management computers can cause more trouble than in a petrol engine, as i believe is the case with some second hand S320 CDIs. Also, diesels have heavier particulate emissions which are more carcinogenic than petrol fumes :eek:

My Dad drives an 320 CDI at the mo, its got buckets of torque although i do find it a bit flat overtaking cars on the motorway. On the plus side, and more relevant to you, its a big 3 litre engine that still returns 36 mpg on a combined cycle. Its a bit "tractor sounding" when idle, you would know its a diesel next to you at the lights, but cruising on the motorway, or even dual carriageway, its amazingly quiet.

Interested? Check out the Honda Accord i-CTDi; 138 bHP @4000 rpm, 251lb ft @ 2000 rpm, gives a respectable while still returning (quoted figure) 52 mpg on the combined cycle!!! Driving on the motorway you might be getting into the 60s. Couple this with a respectable 0-62 mph time of 9.4secs.
Costs 40000 euro, whereas the base petrol model will only cost 32000. It is an "executive" spec though.

Autotrader has a 2004 one, 47000 miles, 28,500 euro

ToxicPaddy

Ive been told by a mechanic I know, that in cities diesels are more economical
but are more expensive to maintain and runas I was thinking along the same
lines as yourself a while back.. So I started observing my driving and mileage
with every tank of petrol.

A tank of petrol for me is approx 6o litres. When driving on the open road,
usually at weekends and when on holidays I can average close to 550 miles
from a full tank but usually around the 500 mark..

When driving in around Dublin on a daily basis, stopping and starting, short
journeys etc... Im lucky to hit the 400 mile mark from a tank of petrol..

My current car has just over 145k miles on the clock and Ive put 105k of
those myself on it in just over 5 years.. however when I sat down and did the
maths the petrol was still more economical with servicing only every 8k - 10k
miles and tax on a 1.6 petrol..

What I would suggest is that you try your car out on the open road and the
longer drive and just make note of how many miles youre getting from a tank
of petrol.. they if its still fairly expensive, look at another car with a similar
size engine and one which is known to be better on petrol, like any of the
typical fleet cars like avensis, mondeos, vectras etc..

Just my 2 cents..

Tox

ds20prefecture

Under 10k your best value will be with Peugeots and Citroens. The HDi is a fine engine.

The 2.0 Xantia HDi is a nice car, Citroëns weren't quite so approximately made back in 2000. The Xsara is smaller and lighter, so might be more fun. It's really ugly though.

The Octavia is worthy enough, but the non-PD VAG TDis are more than a bit rough.

Avoid the 1.8 and 2.5 BMWs (also used in some Land rovers, Opels and Volvos) - they're very noisy and not particularly powerful.

If you can find common rail you should go for that. (there's a nice multipla JTD on CBG - but that's a bit of a leap after something as gorgeous as your alfa)

If you can find a 320d BMW for under 10k you should run a mile It's a great car and worth more so there'll be something terrible wrong with it.

Eoin

Thanks a million ds20prefecture. The multipla is not an option for me. ever . Wouldn't mind the 320d, my budget will more than likely be more than 10K

DirkVoodoo - I love the new accord, think it is a stunning looking car, but out of my price range

ToxicPaddy wrote:

What I would suggest is that you try your car out on the open road and the
longer drive and just make note of how many miles youre getting from a tank
of petrol.. they if its still fairly expensive, look at another car with a similar
size engine

excellent advice Tox, definitely my plan

11811

alias no.9 wrote:

I really hope you're driving a 530D or similar, 400 to 550 miles from a 60 litre tank works out at between 30mpg and 41 mpg.

its a 306 d-turbo,the 400 miles would be mainly city driving,on normal runs it would be 500+ .the fuel mix is also richer than it should be!!!