That is totally dependent on the vehicle and the situation (surface contact vs. gravitic, surface/atmo resistance, load vs power, etc.). In fact, in the real world these numbers are relatively hard to come by - except in specifically delineated test cases (i.e. 0-100-0, 0-60 times, etc. - which still leave a lot of wiggle room). Don't believe the vehicle design supplements make any mention of this, nor support it. And core rules don't offer much at all about such details.
Again, this is why I drop the whole '6 second' round thing - the most believable, and most playable metric is going to be referee fiat!
Relative accelerations/speeds are more important than actual numbers or mechanics - likewise relative timing of actions. I.e. - a motorcycle is generally going to out-accelerate an APC - so it can flee or pursue with ease (timing upto referee and RP goodness factors

. If you need mechanics, use task checks and DMs - maybe the motorcycle fails for any number of reasons (spot of oil/gravel; overheated engine; etc.).
The effects of shooting are, again, simply a skill check - i.e. they succeed/fail to varying degrees. The referee should account for variations in speed and maneuverability (vehicle books support 'agility') with appropriate DMs.
If you are trying to count ammo/shots - simply use extra rolls to determine number of rounds or number of tries (if you want to allow this level of detail). I.e. - let dice determine questionable time issues (just as they normally do with 1d6 for skill checks and 'counted' seconds, etc.).
Hope that helps - I know its vague - but, if you are asking the questions it means you have some expectations (be they real-world or Hollywood cinematic), meaning you can probably handle things in real time without much effort. Players generally don't give a darn, unless things seem way unrealistic (or they are 'losing' and their munchkin-ism is showing

.
P.S. - I'm pretty sure you will get more responses to this topic when more members get online, which might be more helpful...