Turbo diesel cars

goldspanners

Dave101t wrote: »

every diesel ive ever seen has been a tdi or ctdi, i thought they were all turbos

you need to get out more then. most modern diesels are turbos, but the diesel got its slow reputation from the last generation of diesels without turbos.

Mark_Hewitt

A turbo in a diesel brings it up to (and somewhat beyond) the level of a petrol engine. So they all have turbos, but some are common rail and some not.

As far as I can make out common rail allows the same power/torque but with a smaller displacement, but I could be completely wrong!

AdrianHi

Mark_Hewitt wrote: »

A turbo in a diesel brings it up to (and somewhat beyond) the level of a petrol engine. So they all have turbos, but some are common rail and some not.

As far as I can make out common rail allows the same power/torque but with a smaller displacement, but I could be completely wrong!

Common rail is about getting a very high pressure reservoir of fuel physically closer to the injectors and engine so that when you ask for acceleration you get a lot less lag and more consistent power delivery through rev range. Also more refined.
Compare An Audi A4 2.0 TDi 170bhp (direct injection, not common rail) with a 3 year old BMW 320d 163bhp common rail.
The Audi doesn't do much until 2000 rpm, you get a peak of acceleration at around 2200 to 2500 rpm then it starts to tail off. On the 320d you get decent pull from 1500 rpm and it's a much more linear delivery of power up to around 4000 rpm.
On paper they both have similar performance figures, when driving the 320d feels quicker and is a more flexible easier drive.
http://en.wikipedia.org/wiki/Common_rail

Generally common rail systems more fussy on fuel quality, where as you can run all sorts of odd muck for diesel fuel in a TDi and it will keep going.

motorguy

Pssst wrote: »

Many modern cars are now sporting Turbo diesel engines in order to drive up power output and reduce emissions.

If you have one of these, have you realised the cost of repair should the turbo fail?

Also,do you realise the importance of keeping a check on oil level and also replacing the oil and filter regularly with good quality correct spec oil?

Does anyone know which vehicles are more prone to turbo failure?

I was discussing same with my local garage mechanic,a man who has been in business for many years. He seemed to feel that BMW seem a bit prone to failure and told me a particularly horrific and very expensive tale about an X5.

Mechanics love to put the fear of god into people. They all know some horror story.

There was an issue with 320d bmw's circa 2002 / 2003 that was later rectified, but its good to see your local mechanic just broad brushed the entire brand.

I personally wouldnt run anything as complex as an x5 on either a shoestring budget or without a proper warranty, so his x5 story is fairly irrelevant.

dieselhead

I do know from bitter experience that it is so important to change the oil regularly in a diesel, fortunately I have a good friend who is a mechanic and he taught me to change the oil myself.

However I like diesel engines, they give a lot of power, the turbo's provide speed and they go forever!