Originally posted by Robtard
A few things to consider:What would be the cost of this 6-speed transmission with parts and labor factored in?
How much of your driving is highway-driving where you're in highest gear.
How much would your gas mileage from 5th to 6th improve? Most likely, it wouldn't be more than a few mpg. (really depends on the car and how many RPMs your car drops cruising at say 70 mph)
Because if it's going to cost you $2,500 to change out, you only cruise on the highway an average of 15 miles a day and it only gives you a 3 mpg improvement. You might want to just pocket that money for gas or invest in a highly fuel efficient car for the long haul.
Transmission would be expensive, but I would install it myself.
At least 95% of my driving is highway driving
I'm currently revving to 3,000rpm at 70mph and I've read of people just leaving the same gearing in the first five with the 6th dropping it about 1 grand to 2,000rpm at 70 mph, which is substantial.
Cost wouldn't really be an issue to me, honestly. My commute is roughly 40 miles a day, and I have too much fun with the car. I guess I could always get a 335d when it comes out and just make the M my weekend car, but I would never get rid of it. It's too much fun.