Speaking of cars, Diesel vs gas engine

[(vikm)]

I plead ignorance to the nuances behind the diesel and why it may or may not be better than a standard engine. It almost always seems to me that every single time I'm behind a car that is pouring smoke out of the exhaust like something out of Spyhunter, it's a diesel Mercedes or VW (or a car with a blown turbo).

[Speedy]

Your BMW Diesel will get better mileage than the sticker says and your gasser will get less. Once you go Diesel, you never go back to gas. Diesel fuel may not be at every station but you will drive by a lot more stations without needing to stop thanks to the increased MPG. Diesel fuel has lubricants added now that we are using ultra low sulfur fuel. My two TDI's have 10k oil change intervals, the equivalent gasser has 5k oil changes. There is a reason big trucks use Diesel: economy, economy, economy. I've run both gas and Diesel big trucks. The Diesels cost half what a gasser cost to run. And they last twice as long. Your resale will recoup the $2100 additional you will pay. It is messier to fuel a Diesel because the pump nozzles tend to get oily. My wife likes her Diesel because I always fuel it.

But you might consider electric.

[bruceko]

The car I am looking at is the Audi Q5 tdi
Around here most stations have diesel but once we get out of the local area I am not so sure

[gabester]

I know that diesel engines convert the fuel more efficiently than gas engines.

Can someone explain to me why they don't make diesel-electric hybrid cars? This would seem to make the best of all possible vehicular worlds - the battery provides the quick pickup and performance and the diesel extends that mileage longevity even further and allows you to cruise down the highway at decent speeds.

I have no particular feeling about this scenario... but do like the sound of biodiesel.
g=

[davester]

Racer X wrote:
lower maintanence frequency and engine longevity are why diesels are hugely popular overseas.

I'm not sure where you're talking about, but in Europe that was only true in the olden days. The main reason europeans buy diesels is that fuel prices are almost twice as high as here (or more in some cases). Maintenance costs are essentially the same as modern gas cars, and most people don't keep their gas cars to the point where engine longevity is an issue any more (i.e. well north of 100k miles on modern gas cars).

[JoeH]

gabester wrote:
Can someone explain to me why they don't make diesel-electric hybrid cars? This would seem to make the best of all possible vehicular worlds - the battery provides the quick pickup and performance and the diesel extends that mileage longevity even further and allows you to cruise down the highway at decent speeds.

g=

I recall reading that work on ones was being done in Europe, and came across another mention that Rover was planning on bringing a model to the US in the near future. I do know there are buses on the road already in the US that are diesel-electric hybrids. Several were included in a recent purchase of vehicles for the Transit Authority that includes the area around the university where I work.

[Racer X]

gabester wrote:
I know that diesel engines convert the fuel more efficiently than gas engines.

Can someone explain to me why they don't make diesel-electric hybrid cars? This would seem to make the best of all possible vehicular worlds - the battery provides the quick pickup and performance and the diesel extends that mileage longevity even further and allows you to cruise down the highway at decent speeds.

I have no particular feeling about this scenario... but do like the sound of biodiesel.
g=

I have always wondered that. A small aluminum diesel with wet sleeves.

[Gareth]

gabester wrote:
Can someone explain to me why they don't make diesel-electric hybrid cars?

The reason I read, is that both electric and diesel are high torque at low rpm designs so it's rather redundant and the trade off from an electric to a gas engine is better suited to a hybrid drivetrain.

Or, maybe it's because the US is a major consumer of hybrids and it's hard to sell diesels to Americans (especially back when the Prius first came out). No idea, just making that up.

[davester]

What Gareth said is correct. Diesel and electric torque characteristics are not complementary whereas gas and electric are.

[Spock]

428 ft/lb Vs 215 ft/lb - if you intend on towing anything get the diesel.