Popular Mechanics tries out the Jaguar XF diesel
I recently had the opportunity to spend some time with the new Jaguar XF, but here in the US we only get to select from among two powertrains, both 4.2L V8s, one with and the other without a supercharger. Over in the home country, XF buyers can also select from a pair of V6 engines running on either gasoline or diesel. The diesel is a twin turbo 2.7L that was originally developed with Peugeot and is built at the Ford diesel factory in Dagenham England. Popular Mechanics had the chance to spend some time with diesel XF and came away impressed in spite of the writer hating the new Jaguar's grille. The diesel V6 puts out 207 hp and 320 lb-ft of torque which is more than enough for the 3,900 lb sedan. With a 0-60 time of a respectable 7.7 seconds it gets a combined EU rating of 31.3 mpg (US). During the test PM driver managed 29.4 mpg (US) which compares very favorably with the 18 mpg I saw with normally aspirated V8 model. Will Jag bring the diesel XF to the US? At this point no one knows. With Tata Motors now holding the purse strings, anything is possible. If the new diesels from Mercedes, and BMW prove popular, its certainly possible.
[Source: Popular Mechanics]
Reader Comments (Page 1 of 1)
meme 11:39AM (8/08/2008)
"During the test PM driver managed 29.4 mpg (US) which compares very favorably with the 18 mpg I saw with normally aspirated V8 model"
Let's all say it together:
"Diesel != gasoline
Diesel MPG != gasoline MPG"
Diesel is about 15% more dense than gasoline, so it's really 25 to 18 mpg, not 29 to 18 mpg. An improvement, yes, but not a 61% improvement. Diesel MPGs should never be directly compared to gasoline MPGs, just like ethanol MPGs shouldn't be, unless you're talking about how far you can drive on a full tank of a given size. CO2 per unit distance, however, is always a fair comparison.
And, to preempt the argument that happened last time, I had the opportunity recently to speak with the president of an oil supermajor's US branch and ask him whether making gasoline consumes more energy than making diesel. He informed me that this used to be the case, but with the modern diesel desulphurization requirements, it no longer is. So, I'd consider that pretty authoritative.
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Phil 1:19PM (8/08/2008)
So using your figures, the diesel only uses 72% of the fuel (by mass) instead of 62% of the fuel (by volume).
Uing 28% less fuel is still very impressive!
In real life driving the diesel will be just as quick and enjoyable.
Diesel wins!
meme 4:19PM (8/08/2008)
Not saying it doesn't :)
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GoodCheer 6:37PM (8/08/2008)
meme: The only thing I would say by way of disagreeing with you is that diesel and gasoline are both
SOLD by volume and
STORED in fuel tanks of a certain volume.
Which is to say the interface that people have with fuel consumption is by volume, so that's how people think about it. Granted nothing else about them (like energy content, cost, or refining effort) and constant with volume, but what other suggestion would you have? What else would be nearly as meaningful or comprehensible, or accessible?
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