Pretty sure the ice side is actually much better than the fire side. Lets check every vehicle:
Beholder Incin x2 on Buggy Wheels
vs
Kami Elephant x2 on Small Tracks
Easy one, the fire vehicle is laughably bad. No reverse speed; Beholder and Finwhale are borderline useless on an Incin build; not great for long range, not great for close range, not great vs legs, can’t hit copters. On the other hand, Elephants tickle, but they freeze targets for your Narwhals, are easy to use, have great range and can bully copters; Kami is useful if you time it right before eating a Mast shot or need to stay in a fire puddle.
Howl Firebug x3 on Shivs
vs
Ghost Skaldi x3 on Shivs
The fire wheeled flamer deals insane damage, but once again, Howl and Oppressor provide next to no bonuses. It’s also one of the most explosive piñatas in the brawl. The ice “flamer” deals a bit less damage, but it has something like 10 times the range of Firebugs and reduces your target’s damage for the whole team. Ghost and Finwhale provide appreciable bonuses. It also seems a lot less explosive. In both cases, the Shivs are totally pointless when 80% of your opponents are tracked, have legs, or fly; and they are way too weak to tank a couple cannon shots.
Ghost Incinerator x2 copter
vs
Omnibox Jotun x2 copter
Puddle weapons deal pathetic damage against legged enemies (they’re mostly above the damage effect, when they don’t just jump out of it), and obviously can’t deal with copters. Out of those, Jotun at least has the good taste of slowing down flamers, reducing legs’ resists, and buffing your Narwhals massively.
BWC Warrior Mastodon x2 on legs
vs
BWC Warrior Narwhal x2 on legs
The one where there’s a debate IMO. Mastodons deal great damage. They also have worse traverse speed, worse projectile speed, and a wonky handling compared to Narwhals. Narwhals deal brutal damage on frozen targets and handle copters way better than Mastodons. 1v1, the fire walker probably has an edge. In coordinated teams, the Narwhal wins for me, no doubt.
Griffon Firebug x2 on legs
vs
Beholder Skaldi x2 on legs
Don’t pick the fire one, please. Just don’t. Melee range, no cloak, slow, it’s just not good. At least the ice one has decent range and the Beholder cloak.
As far as I can tell, every ice vehicle is better than its direct counterpart except maybe the mastodon/Narwhal pair, and the ice team has much more range, anti-air, support options and build+team synergy than the fire one does. Ice has 4 legit vehicles (don’t pick copters), while fire has… huh… 1.5, and that 1 vehicle is clunky af to use so may the Wasteland gods help you if it’s instalocked by teammates who won’t make the most out of it.