Not to sure about that, but I had a weird experience with a 150mah NiMH. It actually made my car slower

, I thought maybe after a few charges it would improve but did not. So needless to say it's out, I also tried the 100mah NiMH from a ZZ and got the same performance as the Tomy 50mah... so at least I've got a spare.
I don't know if I'm an isolated incident or if upgrading the battery is only positive when doing a "dual mod". Regardless I'm not looking for longer run time *short attention span (result of kbb having more than his share of all-nighters or was it all-weekenders... I forget)

, just more power+awesome handling.