Itsuki_23

Diesel engines do cost more to produce than gasoline engines. Modern diesels have complicated after treatment systems - complex catalytic converters, particule filters etc. Turbocharged engines in general are more complex - first of all the expensive turbocharger, more complex exhaust system, intercooler + ic piping etc. Modern diesel engines use very state of the art high-pressure injection systems and injectors (for example piezo-electric) which are very expensive to produce. Modern diesel engines are very senstive to fuel quality, any failures are costly to repair.

I live in Europe and i have driven many diesel powered cars. Biggest advantage with modern diesel engines is achieved only during highway cruising. 1. With higher (4-5-6) gears the torque band is wider and more usable 2. With good gearbox it is possible to drive fast in low rpm range (accelerate and pass slower cars without considerably raising rpm - hence the low mpg on highway).
In urban driving conditions diesel looses it's advantages. In lower gears torque band is really narrow. Starting off from standstill with first gear the boost comes only at aprox 1800-2000 (also very suddenly with a rush), engine looses its efficency already at 3000rpm, it means the gearbox has to swith form 1 to 2 in a second after starting off from standstill. 1st gear in urban conditions is practically not usable. With modern automatic gearbox you can minimize those effects, but not completely remove them.

But the real concern is actual urban consumption...

Fuel consuption in urban conditions is not really that great. Good example is VW Touareg's V10 TDI 5.0 twinturbo diesel. First of the modern big superdiesels. European factory fuel consumption numbers with city driving is 16.6L per 100km - 14.1mpg. I know two owners of V10 Touaregs, real consumption in urban condition is around 12 mpg. Where is the sense here? RX400h has better acceleration, similar interior space and gets 25.8mpg in city - real numbers are close to 23-24mpg, which is also really good considering the size of the car. I have a family friend who is the owner of one of the first RX400h hybrids in my country. He has been driving it for 1.5 years without a single technical problem, odometer shows 48.000km-s (30k miles). Average urban/highway combined mpg is 27. And on highways he drives average at about 140km/h(87mph).

Also diesel fuel stinks. If you have to refuel the car yourself at the station (like we do in Europe), your hands will get dirty with diesel fuel and the smell doesnt come off even after you have washed your hands. Worse, if anyone has spilled some fuel on the floor and you accidentally step in it, then your whole car interior will stink with diesel. Then you are starting to feel like a truck driver

About IS220d and manual tranny... BMW sells most of its 320d diesels with manual gearboxes, because people in Europe who think economical also prefer a car with basic equipment. Auto tranny adds considerably to the price and gets slightly worse mpg. Same applies to the MB C200 CDI and Audi A4 1.9tdi and 2.0tdi. Those models (also BMW 318i and 520d, MB C180K(143hp), C 220 CDI and E200/220 CDI, Audi A4 1.6(102hp!!!) and 2.0 (130hp), A6 2.0tdi and 2.4...) are cash cows for the european luxury brands and make up most of the sales volume. That is why German brands sell a lot more in Europe than Lexus.

UK's one of most popular car shows on TV Fifth Gear:
http://youtube.com/watch?v=I6Uwz_pQWlA&search=lexus

UK's and Europe's most poplar car show Top Gear:
http://www.topgear.com/content/featu...ries/21/1.html


PS! So from a European car enthusiast viewpoint all this diesel-achieving-immidiate-huge-success-in-USA hype is sounding pretty funny to me.
With certain driving styles and conditions Hybrid cars dont get the factory mpg numbers, but lets not forget, same applies to diesels.