[gravitycop]

test drive a BMW 5 series diesel

2009 X5 35d vs. 2004 X5 4.8is: http://www.motortrend.com/roadtests/suvs/112_0902_2009_bmw_x... http://www.motortrend.com/roadtests/suvs/112_0504_2005_luxur...

              35d    4.8is

        hp:   265     355
     lb/hp:  19.3    14.1
      0-60:   6.7     5.9
  1/4 mile:  15.1    14.3
  60-0, ft:   128    114

http://www.motortrend.com/roadtests/suvs/112_0902_2009_bmw_x...

Though the engine produces a stunning 425 lb-ft of torque at just 1750 rpm, the forward surge doesn't feel dramatic. [...] X5 owners shouldn't feel too cocky [...]

Press the pedal to overtake [...] and the engine note invades the cabin. [...]

We often hear tall tales of European diesels, stories of ridiculous fuel economy, supercar acceleration, and unmatched utility. [...] the truth isn't quite so dramatic

[jacquesm]

Comparing a 3.5 liter diesel with a 4.8 liter petrol car, that's like comparing apples and oranges.

Topgear on those same cars, better data: "

All the bigger BMW engines are wonderful and the X5 boasts three of the best. You can go for a ‘base' 3.0i petrol(268bhp, 0-62mph in 8.1 and 130mph), the diesel version of the 3.0litre (232bhp, but because of the extra torque 0-62mph in the same 8.1 and the same 130mph top end), or go for the range-topping 4.8-litre V8 with 350bhp, 150mph and 0-62 in 6.5."

So, exactly the same performance for two 3.0 liter engines by a quality manufacturer, one diesel, one petrol.

And yes, if you increase the displacement the petrol engine will get more power but that is no longer a fair comparision.

[gravitycop]

if you increase the displacement the petrol engine will get more power but that is no longer a fair comparision.

Why? Are they both turbocharged? http://www.google.com/search?q=bmw+x5+35d+biturbo Do they both weigh the same and take up the same amount of room in the engine bay? Do they both cost the same?