SMC is also a good brand. 1/5. Assuming you are running 8s? Here are ome 4s packs from SMC:
https://www.smc-racing.com/index.php?route=product/category&path=67_96
Comparing smaller cars (less heavy) to bigger cars (alot more heavy)
Bigger and heavier cars will take more power (more discharged the battery comes) in order to get up moving / up to speed)
Sounds about right.
I agree with @Tunedpipe said.
More mah is more capacity, which more run time. But also depends on how you drive. Like the example between bashers are crawlers, crawlers last longer as your going slower.