13,8 V idling charging voltage ok ?

[James Sweet]

I don´t know which kind of gas guzzlers the gasoline versions of the 850
are, but the 2,5 l Audi TDI diesel runs on about 6,5 - 7 liters/100 km
(makes 36 - 33,6 mpg), which was good fuel economy at that time for that
car size.
Franz47

The gasoline versions are not too bad, not as economical as diesel though.

Still, diesel tends to be more expensive than premium gasoline in the
US, and for a while it was a lot more expensive, so the lack of
popularity is not too surprising. We had a lot of really bad diesel cars
back in the 80s too, and only a relatively few good ones from Europe.
It's starting to gain some popularity but it's still mostly used in trucks.

 

[franz47]

Still, diesel tends to be more expensive than premium gasoline in the US, and
for a while it was a lot more expensive, so the lack of popularity is not too
surprising.

Traditionally, diesel was definitely cheaper than gasoline here in central
Europe, only since about 10-15 years the diesel has practically reached the
gasoline prices. Especially in Eastern Europe befor the fall of the iron curtain
diesel was much cheaper than gas. Now they have the same price structure as we.

We had a lot of really bad diesel cars back in the 80s too, and only a
relatively few good ones from Europe.

I think there were years when there were more new diesel cars registered
annually here that gasoline cars, though they still are more expensive than
gasoline cars, only god knows why they are more expensive.
Franz47

 

[James Sweet]

I think there were years when there were more new diesel cars registered
annually here that gasoline cars, though they still are more expensive
than gasoline cars, only god knows why they are more expensive.
Franz47

Why the cars are more expensive is easy. A Diesel engine is more complex
and requires much stronger components. Tighter tolerances, stronger
materials, more precise machining and higher rejection rate. Components
like the injection pump, injectors, plumbing, fittings have to be much
stronger to tolerate the extreme pressure, you need a bigger battery,
wiring, starter motor, heavier suspension components for the heavier
motor, it all adds up to a more expensive car. Generally you make that
back in fuel savings though.