Posted by Troy Rudolph on August 04, 1999 at 12:55:28:
In Reply to: '80 528i Auto to 4 or 5 speed? posted by raz4000 on August 04, 1999 at 12:06:49:
Mine is a '79 so it came with a 4-speed. I converted to a 5-speed a few years ago. For me the advantage was highway crusing. The ~19% overdrive drops the revs quite a bit. At 80mph the thing was turning ~3900 rpm in fourth. Now, in fifth, it turns slight less than 3200 rpm. As a result, the car is much quieter and much smoother on long trip. Also, the gas mileage is much better. It went from around ~19 to around ~25 on the highway. Of course, the around-town figure didn't change.
Since you have an automatic, you'll also get a big boost in performance. You'll most likely pick up a full second on the 0-60 time. But, if you spend a lot of time in traffic, you'll have to shift. Everything is a compromise.
Now if you could find a way to install a 4HP22 (four-speed overdrive auto) in there, you *might* have the best of both worlds. I have no idea how to go about it though.