What is a Volvo TDI

Volvo was never selling it in the USA...

Very low consumption for such a big and powerful car. Avg only 6.5 liters per 100 km. I don't know US or GB MPG now...

It started in 1996 with 850 series, and lasted till year 2000 in S/V70 models. Volvo calls the engine D5252T - which is 5 cyl Audi 2.5 TDI engine with 103kW and 290 Nm of torque.

TDI is usually taken to mean Turbo Diesel with Intercooler, or perhaps Turbo Diesel Injection - depending on who you ask! Since all diesel engines are injected, I prefer the Intercooler version. Some cars (probably not Volvo) were available in TDI or plain TD (with no intercooler) versions.

The TDI designation has been common in the UK - and probably other parts of Europe - since at the least the mid 1990's.

TDI is usually Turbo Direct Injection.

Tim..

Tim.. schrieb:

And the current TDIs are no Audi-engines anymore. They are development of the light alloy 5-cylinder gasoline engine developped for the 850.

Current engines either have 163hp or 185hp. In Europe they come with a particles-filter which lowers emissions massively.

I'm owning the 185hp-version after selling my T5 (2001). I simply love the diesel-engine.

I *guess* in the foreseeable future Volvo will be selling the Diesel-engine in the US.

Joerg

Thanks for bringing me up to date. I agree with you, if TDI means injection rather than inter-cooler, it is redundant just as PCV Valve is redundant (Pollution Control Valve Valve).

Diesel engines have dropped out of favor here because the price of diesel fuel has gone up considerably and is hard to find at many gas stations and truck stops aren't very car friendly. Also, there are not many good diesel car mechanics around in the US so it is a chicken/egg situation.

Diesel and premium gasoline prices have been quite close and moved in tandem for a long time. So the attraction of a diesel engine would be if the improved milage is enough to offset what is usually a more expensive engine. The cost of operating a high mpg car like the Toyota Corolla or Honda Civic is probably a lot closer to the cost of operating a comparably sized diesel car because those cars burn relatively cheap regular gas while diesel fuel is priced above premium much of the time.

I believe diesel fuel is taxed at a lower rate than gasoline in europe and that is likely the reason for it's popularity over there.

Positive Crankcase Ventilation, actually.

Tim..

In some countries, yes, diesel fuel is taxed less than petrol (at least Finland). But diesel-powered cars are taxed more heavily than petrol-powered. I think this must be somehow different in elsewhere Europe where diesel-powered cars are far more common. Of course, reasons could include that diesel engines are more efficient and generally more durable.

In this case with VW Audi engines, TDI means "Turbo Direct Injection". I don't think that diesel engines before TDI was introduced were direct injection diesel engines...

All manufacturers call their diesel engines differently. TDCI, CRDI, DTI, CDI etc. Since Volvo started making their own diesel for cars it simply calls it D5...

I suspect that localities that have a large number of diesel powered cars encourage their use by lower tax rates.

I have yet to read of a study that shows diesel engines are any more durable, reliable or long lived than gasoline engines designed for use in passenger cars. In my experience both designs will last for several hundreds of thousands of miles IF they are maintained and serviced frequently.

Again in my experience the long term cost of maintaining and servicing a diesel engine is roughly the same as a gasoline engine.

It used to be that the major maintenance item on diesel cars was the frequent oil changes. Today the maintenance intervals seem to be the same as gas cars. However, most oil companies still recommend more frequent oil changes with diesel engines. Diesel engines are very simple. On the other hand, the gas engines are quite complex and service is more involved. Diesel engines have a service life 5 to 10 times as long as gas engines.

Diesel engines have different components from gasoline engines but they wear too and some are quite expensive to replace. Diesel engines use glow plugs which do go out. Diesel engines typically require more oil, use a larger more expensive oil filter and should have their oil and filter changed frequently. Air and fuel filters tend to be larger and more expensive.

Both gasoline and diesel engines designed for automobiles can and regularly do run for many hundreds of thousands of miles. Diesel and gasoline engines designed for industrial or commercial use will naturally have a much longer duty cycle built into the design, but they will cost a lot too.

Direct injection: At the end of the piston stroke, diesel fuel is injected into the combustion chamber at high pressure through an atomising nozzle. The fuel ignites directly from contact with the air, the temperature of which reaches 700-900 °C (1300-1650 °F). It was the initial method used in diesel engines. Direct injection was patented by Akroyd-Stuart in

1890. Rudolf Diesel used direct injection when he patented compression ignition in 1892.

Indirect injection: An indirect injection diesel engine delivers fuel into a chamber off the combustion chamber, called a prechamber, where combustion begins and then spreads into the main combustion chamber, assisted by turbulence created in the chamber. This system allows smoother, quieter running, and because combustion is assisted by turbulence, injector pressures can be lower, which in the days of mechanical injection systems allowed high-speed running suitable for road vehicles (typically up to speed of around 4,000 rpm). The prechamber had the disadvantage of increasing heat loss to the engine's cooling system and restricting the combustion burn, which reduced the efficiency by between 5-10% in comparison to a direct injection engine, and nearly all require some form of cold-start device such as glow plugs. Indirect injection engines were used widely in small-capacity high-speed diesel engines in automotive, marine and construction uses from the 1950s. Use of indirect injection was somewhat curtailed when direct-injection technology advanced in the

1980s.

As a follow up, TDI is an implementation of "common rail direct injection."

In older diesel engines, a distributor-type injection pump, regulated by the engine, supplies bursts of fuel to injectors which are simply nozzles through which the diesel is sprayed into the engine's combustion chamber.

In common rail systems, the distributor injection pump is eliminated. Instead an extremely high pressure pump stores a reservoir of fuel at high pressure - up to 1,800 bar (180 MPa, 26,000 psi) - in a "common rail", basically a tube which in turn branches off to computer-controlled injector valves, each of which contains a precision-machined nozzle and a plunger driven by a solenoid.

Most European automakers have common rail diesels in their model lineups, even for commercial vehicles. Some Japanese manufacturers, such as Toyota, Nissan and recently Honda, have also developed common rail diesel engines.

Different car makers refer to their common rail engines by different names, e.g. DaimlerChrysler's CDI, Ford Motor Company's TDCi (most of these engines are manufactured by PSA), Fiat Group's (Fiat, Alfa Romeo and Lancia) JTD, Renault's DCi, GM/Opel's CDTi (most of these engines are manufactured by Fiat, other by Isuzu), Hyundai's CRDi, Mitsubishi's D-ID, PSA Peugeot Citroen's HDi, Toyota's D-4D, Volkswagen's TDi, and so on.

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Since current gasoline engines have 10-25 year and 200-300 K mile lives, I dunno about the 5-10 times as long claim. 50 to 250 years or 1 to 5 million miles?

Mike

Forget about servicelife. The pluspoint of old style diesels was that once they had started they would keep running. With modern electronics and high pollutionstandards that has become a bit more doubtfull. Modern engines last long enough for something else to give up. However loads of bottom torque, 1000 km's on a tank and depending on the mileage slighty lower operating cost still count. As was needing only one companypump to fill the trucks and the cars

According to a study by the University of Colorado Leeds School of Business, diesel trucks have a service life of one million miles (which is 5 to 8 times the service life for cars you quoted). They accumulate this in about 7 years. I have no data on diesel cars, but it is probably less because most owners don't keep up the required maintenance, as simple as it is.

Oh come on now, at least compare engines designed for comparable applications. Comparing the service life of a truck diesel engine to that of an engine used in a car?

It is certainly possible to produce a car engine (gas or diesel) with an average service life of 1 million miles but the cost would be prohibitive for most owners. And purposeless because most drivers would not use it for that long.

It's time to kill that myth.

Well, 3 to 5 times as long. OTOH, if the hauling trucks were used for trips to the store to pick up milk I doubt the advantage would be nearly so great. Short trips take a toll on any engine. Mostly I see claims of double life for diesels compared to gasoline engines in equivalent service.

I'm not knocking diesels; the work truck I've had the past year is a turbo diesel and mostly I love it. (Not the balky six speed tranny, but that isn't a fault of the engine.) I've been warned to let it warm up a bit on cold days and it is a nightmare for merging or left turns in heavy traffic, but on the road it is powerful and the fuel economy is just about double what the previous "gasser" gave. That means I can go to remote areas far from home and not have to worry about finding an open gas station. A month after I got it I found myself in the far reaches of the Navajo reservation around midnight. The old truck would have been getting mighty low on gas by then. The torque characteristics are also very nice for off-road operation, especially in sand and for rock crawling.

I also hear the common rail diesels have better cold-starting and drivability characteristics than even the TDi's. They are even supposed to be better in terms of smell, although the characteristic diesel clatter is controlled only by sound insulation.

I understand your enthusiasm for diesels and I hope I live to see serial hybrids (electric cars with on-board generators) using advanced diesel power plants. It could be an amazing thing.

Mike