Can the $50k to $60k difference (if this is the case) can justify the fuel economy (0.64L/100km or 2mpg)?
Babybenz 發表於 2011-8-8 23:08 
Simon does 150km on a daily basis, assuming 90% of the daily trip is highway using top gear.
5sp final gearing ratio = 3.53
6sp final gearing ratio = 3.13
6sp has approx. 11.3% taller gearing than 5sp, and assuming 5sp is returning $1 per km, and further take a wild guess that the mechanical losses + extra gear weight of the 6sp gear box results in 1.3% losses, hence the net fuel saving is approx. 10%.
150km x 90% x $1 x 10% = $13.5 per day
Assuming 5 days a week, 52 weeks per year.
$13.5 x 5 x 52 = $3,510 p.a.
Assuming 3 yrs ownership
Fuel Saving = $10.5K over 3 yrs.
Further assuming a 6sp will have a $10K residual value over the 5sp model (of similar age), therefore you can consider a 6sp model with $20.5k premium over the 5sp model (base on fuel efficiency + residual value) |
