From the RT3 manual:
I listed the amount of time needed to reach top speed for each level here. Repeated for easy reference:Acceleration - Measures how fast this locomotive reaches top speed from a standing start.
Code: Select all
Hrs: Level:
4 Instant
15 Virtually Instant
25 Ultra Fast
36 Very Fast
47 Fast
58 Above Average
69 Average
80 Below Average
90 Poor
101 Very Poor
112 Extremely Poor
Same data in a graph: In my old explanations I used the term "linear" acceleration, but I believe the correct term is "constant" acceleration. In constant acceleration starting from standstill, during a given period of time an object will have an average velocity of approx. half of the final velocity (hope I got that right, sorry in advance to any math geniuses).
Since we know how long acceleration to top speed takes for a given level, we can translate this to say that a train accelerating to top speed is essentially traveling at top speed (for illustration assuming a flat-ground route, so this is constant for the entire journey) for HALF the period of acceleration.
From the list above we see that Above Average takes 58 slow time hours (half- normal days). Halve that to give 29, so during those 58 hours the train will travel approximately the same distance as 29 hours at top speed.
Compared to a train already maxed out at constant top speed (no acceleration time) here's the percentage of this distance covered by the various acceleration levels. Notice the scale is large enough to see 6-month journeys (360 half-days). And finally a comparison to see the mileage advantage of a higher/faster acceleration level. This is once again expressed as a %. ***If anyone wants a spreadsheet that generates specific values or one with a range of most values in a big table. Let me know.***
For the purpose of comparing locos, we will see different top speeds. I'm not 100% sure, but I believe that the factor of benefit/disadvantage for differing acceleration levels can be calculated separately from the factor of benefit/disadvantage for outright speed differences.
What about grades?
Obviously, there are grades in a real game, which for one means that a maximum speed will be the target of acceleration instead of top speed. Any grade severe enough to cause deceleration will most probably will increase the amount of total time on a run that a loco is accelerating. Downhills are accleration boosts, but on the overall I believe a train on a graded route will be more affected by it's accleration rating than on flat-ground. Basically, my guess is that the higher/faster levels probably have somewhat more advantage on graded terrain. I don't think it's too much, so I'm not going to delve into details for that.