TwinCitiesS8

Top Gear runs a D3 Audi A8 4.2TDI from London to Edinbourough and back on one single tank of fuel! Amazing!<ul><li><a href="http://www.bbc.co.uk/topgear/clips.shtml?13">http://www.bbc.co.uk/topgear/clips.shtml?13</a</li></ul>

Beartrap

(I think there were three parts.) It's well worth it.

Shows you what we're missing over here.

A8bil

As much as Jeremy is oft accused of being a German car hater (check out his review of the porsche 911), his admiration for the engineering incorporated in that TDI is unbridled. Should be...that's a 20.2 (Imp.) gal. tank, which is several gal short of my A8L, and he was still able to do 800 miles.

Can't wait for when you can run bio-diesel in them.

Bill G.

hranaRS9oolalathumpr

Love him or hate him, Clarkson has never produced a spot that I'd wished I hadn't seen.

greenbird

550 miles on a tank averaging 68mph with winter tires. I bet I could get 650 or 700 with summer tires and limiting to 65mph.

tozoM8

$3.79 premium vs $4.39 diesel here in Chicago. The purchase price is higher too.

A8bil

Maybe...three years ago I drove my A8L from San Francisco to San Diego and part way back on one tank. Total mileage before fill up was 588. A good part of the drive, however, was spent at 80+ on I5 and about 30 miles was spent putzing around in Poway and Rancho Santa Fe. Probably could have exceeded 600 easily had I kept it to under 75 and had more freeway at the end. Mileage computer showed an average of 28, but it tends to read a little high.

Strange thing was when I drove back up to SF, I averaged around 24.5. Must be because I was driving uphill.

Bill

skiracer

1 gallon of gasoline = 123,222 BTUs energy content
1 gallon of Diesel = 130,500 BTUs
1 gallon of Ethanol = 75,700 BTUs.

Using Tozo's price of a gallon of gasoline as a baseline ($3.79/gal), then based only on energy purchased, the cost of Diesel should be:
$3.79 *(130500/123222) = $4.02/gal
The cost of Ethanol should be:
$3.79 *(75700/123222) = $2.33/gal.

These prices per gallon would reflect parity between the fuels as far as cost per BTU (which is what you are buying the fuel for in the first place).

The comparison for gasoline to ethanol is almost a perfect match for relative MPG between the fuels (since they are burned in the same way in the same engines), but the comparison with diesel isn't quite as straight forward. Since a diesel engine burns the fuel at much higher compression ratios, a greater percentage of the available energy in the fuel is converted to mechanical energy and less is lost to thermal energy. Diesel used to be a real bargain in terms of cost per BTU and cost per mile, but the oil companies have figured that out and are charging prices that reflect the realities of modern engines as well as the true energy content of the fuel.

audikillsbmw

They said they'll be bringing them next year.