Petrol versus diesel
These comparisons are simplistic. I had an STX petrol 4 x 2 and now an ST diesel 4 x 4. Fuel around town in the petrol was 12.3 litres per 100 km regular as clockwork over 4 years. Diesel is 10.3 litres per 100 km same trips. That makes diesel 16% cheaper than the petrol on a straight mileage comparison.
Over 18000 km per year (the dealer's national average and, as it happens, my own average) the petrol runs out at 2214 litres per year and the diesel 1854 litres, a difference of 360 litres. With diesel an average 9c per litre dearer (benchmark $1.24 for petrol and $1.33 for diesel) that's $2,745 per year for petrol and $2,465 per year for diesel, a difference of only $280.
The diesel is, however, $2,000 dearer to buy up front. Finance that difference at 10.25% and the difference reduces by $205 to $75! Then throw in two $280 services (5,000 and 15,000) for the diesel and you are $485 behind in the diesel.
...and we haven't looked at what a bad "fix" bill might be for the two cars.
As a "driver", the Nissan V6 beats the diesel hands down. For towing, once you get out of first, the diesel wins.
I have no idea (other than the general population's readiness to swallow all the bulls...) why the re-sale on the V6 is so poor.
If they still made them, I'd still be in a new V6 4 x 2.