Diesel cars

JaManSnowFlake

In a report on RTE today car sales are flat on March last year. What I found interesting is that 70.4% of new cars sold are diesel.

Is this due to a change in the taxation do the running costs of a diesel now out weigh a petrol?

http://www.rte.ie/news/business/2013/0408/380309-number-of-new-cars-licensed-creeps-up-in-march/

puddinboxxx

diesel cars will do almost twice the mpg as petrol cars,,if you do a lot of miles its way cheaper regardless of tax or anything

NIMAN

I also think diesel saw a big increase in sales mainly due to the change over to emissions as a guide to the tax rate of the car from 2008.

Diesels, with DPFs fitted, have lower emissions.

MetzgerMeister

puddinboxxx wrote: »

diesel cars will do almost twice the mpg as petrol cars,,if you do a lot of miles its way cheaper regardless of tax or anything

This is only true for long journies on motorways etc. There is nowhere near such a difference in stop/start town driving where the engine isn't getting up to operating temperature.

It's also this kind of driving that causes DPFs to clog up.

MidlandsM

There is a bit of a fad going on all the same with diesels.

Shure you have the likes of holy mary going into renault and buys 131 a diesel fluence, and only goes to mass 2 mile down the road and into the town, maybe 100 miles a week!

I see it all the time.

NIMAN

They were well marketed.

A lot of people would be better off with petrols for all the miles they do.

ironclaw

MetzgerMeister wrote: »

This is only true for long journies on motorways etc. There is nowhere near such a difference in stop/start town driving where the engine isn't getting up to operating temperature..

I appreciate that viewpoint and I agree with the petrol/diesel mileage debate. However, why are vans etc continuing to be fitted with diesel engines? Surely at this stage if this was true couriers / city transport business would be up in arms about it. Also I would imagine it would be a consumer issue if engines were failing due to persistent city driving.

Has diesel tech gone past this stumbling block?

Ardent

Was in frank keanes in blackrock recently getting my car serviced and got the usual trading up spiel. Looking at their stock list, not a single petrol car?! No demand I was told.

dgt

ironclaw wrote: »

However, why are vans etc continuing to be fitted with diesel engines? ?

I saw a petrol Boxer the other day. Must be frightening on petrol :eek:

Viper_JB

ironclaw wrote: »

I appreciate that viewpoint and I agree with the petrol/diesel mileage debate. However, why are vans etc continuing to be fitted with diesel engines?

Because diesel engines generally have more torque and pulling power surely?

sparksfly

We are using 5L/100KM average on a 1.9TDI Octavia and 8.1L/100KM average on a 1.4L petrol Hiyundai IX20.

Both doing similar type of mixed motorway / urban driving.

Previously had a 1.4L petrol Fabia and a 1.9L Diesel Mondeo.
Mondeo had less than two thirds of the running cost of the Fabia even though it had about 25% greater weekly milage.
The performance of the TDIs was/is vastly better than the petrol models.

I will not buy another petrol car again.

CiniO

Viper_JB wrote: »

Because diesel engines generally have more torque and pulling power surely?

Why would they have more pulling power?
If car reaches 100BHP max, then it's 100BHP no matter if it's petrol or diesel.

More torque produced by diesel engine is lost by higher transmission ratios.

So in general, having the same car in two versions (diesel or petrol) with similar BHP rating, will make those cars very similar performace.

GavMan

To be fair, with some of the (claimed) MPG figures new petrol engines are quoting, there could be a return to petrol soon.

I would certainly pick a modern, clean, economic petrol over a diesel if the option was there.

Then again, my old man went diesel and hasn't looked back. Not a huge mileage day to day either

CiniO

JaManSnowFlake wrote: »

In a report on RTE today car sales are flat on March last year. What I found interesting is that 70.4% of new cars sold are diesel.

Is this due to a change in the taxation do the running costs of a diesel now out weigh a petrol?

http://www.rte.ie/news/business/2013/0408/380309-number-of-new-cars-licensed-creeps-up-in-march/

It's mostly due to taxation.
Petrol engines use more fuel according to manufacturers data, so they have higher CO2/km emission ratings.
This makes them more expensive to buy (due to VRT based on emissions) and more expensive to tax (due to motortax).
That's why so many people go for diesels.

Viper_JB

CiniO wrote: »

Why would they have more pulling power?
If car reaches 100BHP max, then it's 100BHP no matter if it's petrol or diesel.

More torque produced by diesel engine is lost by higher transmission ratios.

So in general, having the same car in two versions (diesel or petrol) with similar BHP rating, will make those cars very similar performace.

Fair enough I don't drive a truck or anything but I would have thought that extra torque when getting the load moving would be useful, by pulling power I mean like trailer pulling power, so like....torque again I guess.

walus

JaManSnowFlake wrote: »

In a report on RTE today car sales are flat on March last year. What I found interesting is that 70.4% of new cars sold are diesel.

Is this due to a change in the taxation do the running costs of a diesel now out weigh a petrol?

http://www.rte.ie/news/business/2013/0408/380309-number-of-new-cars-licensed-creeps-up-in-march/

No wonders that the air quality in major cities has not improved at all for the past 10 years. More diesel engines more air pollution.

CiniO

Viper_JB wrote: »

Fair enough I don't drive a truck or anything but I would have thought that extra torque when getting the load moving would be useful, by pulling power I mean like trailer pulling power, so like....torque again I guess.

But you don't get any extra torque.
Higher torque from the engine is lost by higher gear ratios, so effectively you get the same kind of torque on driving wheels. (comparing diesel to petrol)
And it's the torque on driving wheel which you feel as pulling force.

So generally you might have f.e. 300Nm torque from diesel engine, and only 150Nm from similar power petrol engine. But on driving wheels you get the same value due to transmission.

Only advantage (or disadvantege) of diesel is that torque is available form much lower revs. Most passenger diesel cars get their max torque below 2000rpm, while petrol more like around 4000rpm.

So to get the same performance, you have to rev petrol engine to much higher revs. But that's just a characteristic of petrol engines and they are built to be revved.
Petrol's use more fuel, but are more suitable for city driving, short distance driving, etc. They are also cheaper to manufacture, and are simpler and therefore cheaper to maintain (maybe except really modern petrols with low emissions).

NIMAN

I have recently been thinking about a petrol car as our 2nd car, as it will be doing much shorter runs, but a big worry for me would be any resale value.

I think I might get a bargain, but I will have to sell for next to nothing if the rise of diesel sales continues as it has been recently.