Here is an explanation: (the figures are made up, but
should be about right)
| Gear | MPH range | MPH gained | Time (s) | mph/sec (effective acceleration) |
| (v. low) | 0-5 | 5 | 3 | 1.67 |
| 1st | 0-15 | 15 | 5 | 3 |
| 2nd | 15-35 | 20 | 6 | 3.33 |
| 3rd | 35-70 | 35 | 10 | 3.5 |
| 4th | 70-100 | 30 | 20 | 1.5 |
| (v.high) | 70-100 | 30 | 40 | 0.75 |
Therefore you gain more speed per second OVERALL (not peak or average) in 3rd.
The reason behind this is that the actual act of changing gear takes a second or
two, and this has more effect on the time in lower gears.
I always find I'm 'mucking around' in 1st and 2nd, but 3rd is the gear where I
can really let the car go and watch the speedo rise.
With a longer diff 2nd would be better than 3rd. Depends on your setup.