[Maxib37]

What floats your boat and why...

[tawia]

Diesel = MPG + Torque. Better for everyday.
I love high powered petrol too but can never afford the running costs

[ovekvam]

Diesel has a more massive midrange torque punch, and slightly lower fuel costs.

Apart from that, petrol is better at everything.
- Starts easier on really cold days
- Makes less noise and vibrations
- Has a wider and more flexible rev range
- Copes better with short trips
- Smells better
- Less NOX emissions

Comparing a turbo diesel with a turbo petrol engine with same displacement, the petrol engine will usually have more power as well. The difference in fuel consumption has become smaller the last few years.

Unless the car will be running all day long as a delivery car or taxi, I would go for petrol.

[theotherjohn]

As Tawia said
Diesel = MPG + Torque.
& less road tax which isn't such a big deal now but makes it much easier when the time comes to sell on
Although modern diesels have smoothed out the torque curve a lot; there's not the sudden "push in the back" grunt than my direct injection TDi Golf which I sometimes rather miss

[ovekvam]

If you compare two 2L turbo engines, one petrol and one diesel, you will find that the diesel has the highest torque peak. The petrol engine has more torque both on high (5000) RPM and low (1000) RPM.

When it comes to road taxes, that could easily change even more in favour of the petrol engine. More and more cities are implementing restrictions for diesel engines because of the high NOX emissions. In Norway it's getting more and more difficult to sell diesel cars because people are afraid of increased diesel taxes.

[AusF20/F48]

Its a personal thing
Go with what you like
Both engine types are excelent.

I prefer the 2lt bi turbo petrol in the 125i

[ovekvam]

Originally Posted by AusF20

I prefer the 2lt bi turbo petrol in the 125i

I believe it is twinpower turbo, not bi turbo.
Bi turbo means two turbos.
Twinpower turbo means one turbo with two inlets.

[logiclee]

Although I have a history of some high powered petrols my current VW has VAG's latest TDi technology, I've had several TDi's and like the mid range. My wife's previous cars have been TDi's

So looking at a replacement for her we had settled on either a 118D auto or 120Dauto.

As we needed to try different suspensions and seats one of our test cars was a 116i. We couldn't believe how smooth it was and the spread of torque. Maximum torque from just 1350rpm and although peak figures not as high as the diesel the gearing is lower so in gear performance feels strong. We were trying Auto's and felt the 116i with 8 speed Auto was a better drive than both the 118D and 120D. Sure the 120D was quicker but the 116i never felt underpowered.
So we asked for figures on the 116i and were surprised to find for our mileage it was the cheapest option.

So we went to the dealers for a diesel and eventually came back with a petrol on order.
The new direct injection turbo petrols have to be tried before you make up your mind.

Cheers
Lee

[Diesel130]

Petrol... provided it has 6 cylinders too

[AusF20/F48]

Originally Posted by ovekvam

I believe it is twinpower turbo, not bi turbo.
Bi turbo means two turbos.
Twinpower turbo means one turbo with two inlets.

Thanks, however, to be 'correct' it can be called anything
The only word recognised for the device is 'TURBOCHARGER'.
Each manufacturer can call their version what they like
It can be called a two stage, Bi, Twin power, multi stage or whatever
The reference was to the petrol (gasoline) (benzene) engine in the 125i. Sorry, if I was not being specific enough.

[wolz]

I went for diesel mostly for the lower consumption and good performance. Starting up at cold winter-temperature is no issue nowadays, at worst there is a second or two delay before start but I think most ppl can live with that. Same with noise and vibration imo, almost the same as petrolengines nowadays. Only downside is the boring engine-noise I think.

What i find impressive with the diesel now from bmw is the fact that it pulls really good from ~ 1700rpm all the way up to 4500rpm. Back in the days diesel engines really died as the revs went up and the rev-span where the action was were really narrow.

[ovekvam]

Originally Posted by wolz

I went for diesel mostly for the lower consumption and good performance. Starting up at cold winter-temperature is no issue nowadays, at worst there is a second or two delay before start but I think most ppl can live with that. Same with noise and vibration imo, almost the same as petrolengines nowadays. Only downside is the boring engine-noise I think.

What i find impressive with the diesel now from bmw is the fact that it pulls really good from ~ 1700rpm all the way up to 4500rpm. Back in the days diesel engines really died as the revs went up and the rev-span where the action was were really narrow.

But the turbo petrol engines have an even wider RPM span, and even better performance.

The diesel engines do not make much heat since they are very efficient. To compensate for this on cold days, various electric heaters are used. This drains the battery energy, and eventually the car will not start. Many diesel car owners need to use external chargers in the winter.

There is also a problem with exhaust gas being recycled into the intake, and this system is condensated and then frozen. It has caused a lot of problems in Norwegian diesel cars. Same with te crankcase ventilation system.

[tawia]

As for battery draining cold starts etc, come on guys, it's 2012 not 1912!

[will-w]

I went for a diesel as I was doing 18,000 miles a year.

I've just got a new job where I'm doing 5,000 miles a year.

I wish I had gotten a 118i instead of 118d. It's not the end of the world as I've not filled up for over 3 weeks now

[rickk]

Originally Posted by ovekvam

Twinpower turbo means one turbo with two inlets.

Actually, I think that's twinscroll

If I recall correctly the latest marketing bla on TwinPower was that it stands for DFI + Valvetronic.

- Rick

[rickk]

I own a E46 320d which isn't bad, but it also reminds me how much I like to redline a car which is why I prefer petrol all the time.

That's why I'm very happy with the recent improvements in fuel consumption and torque in petrol engines.

[ovekvam]

Originally Posted by tawia

As for battery draining cold starts etc, come on guys, it's 2012 not 1912!

Exactly. Everything in the car is electric now, but there is still only one power source. I know a fair share of people who run out of battery power with modern diesel cars in the winter. It was less of a problem 20 years ago.

[wolz]

I've never heard of anyone having that problem, nor have I experienced it myself. They must have been unlucky.

[ovekvam]

Originally Posted by wolz

I've never heard of anyone having that problem, nor have I experienced it myself. They must have been unlucky.

It is not about luck, it is about how you use the car. If you drive primarily short trips, the battery will never be sufficiently charged. The diesel cars have an electric heater for cabin air, the seats are heated, the rear windscreen, the mirrors and lots of other small things that soak electric power.

Petrol engines take less energy to do a cold start, and the engine produces more heat, so less additional heating of the cabin is necessary.

[logiclee]

On smaller uk diesels you don't get all the fancy extra heaters so not a lot of battery issues but my wife only does short trips and she would complain all the time in freezing conditions that her car took ages to defrost and was very slow to warm up (VAG 1.9TDi).
Partly why we are happy to be swapping her back to petrol.
My Passat 2.0CRTDi does have aux electric heating system and gives warm air within the first minute or two but it does really hit fuel economy when this is on with the heated seats, heated screens, heated mirrors, heated washers, headlights, blowers, wipers etc.
Luckily it then normally gets a 30 mile high speed run so no battery issues either.

Cheers
Lee

[BMW-RaceR]

Petrol!
For the reasons explained in this thread.
I would only consider diesel if long distance commuting was the main purpose of the car and you were not doing track driving, or frequent short trips.

[tawia]

My E90 320d had all these things burning in the winter, short trips, car was 7 years old on factory battery and NEVER did I have issues with battery charge, or lack of it!

Could have bought an M135i for the same price as my forthcoming 125d M Sport (with lots of extras) and trust me, I had many a sleepless night deciding which to buy but I decided on the d in the end cause I want to enjoy the car everyday and not have to think about putting £20 in the tank everytime I open the door. Sure, maybe if I was earning more money I wouldn't have to think of these things but with a girlfriend that wants to get married/house etc I had to think about costs and with the same 450nm torque as the 35i I'm sure I will be smiling anyways... @ 50mpg