I state now that any GEV with 0 to 2 attack cannot exceed 4/3 movement without roads, no tactical load or jet assisted take-off.
For each 1 DEF, 1 ATT, or 0.5 RNG it slows the GEV down by 1 MOV (starting with MOV1 then applies to MOV2 then back again). This gives the GEV up to six points to spend among it's three traits, ATT, DEF and RNG but leaves it's MOV to 1 hex per turn if they are all spent (in my honest opinion, it's greatest strength). You would probably notice that I made range expecially expensive. This is because to give range, you have to have both electronics, barrel lengths AND heavier ordinance. The technology is just not there yet to carry vast amounts of weight in a small package and then speed at the movement suggested (see below for tech level reference). Additionally a GEV with loads of fire power and DOES move fast would most likely be a prototype and would therefore be invaluable and not expended in battle where it could be captured, studied and replicated by the enemy. A GEV/PC can barely handle fifteen 1,500 lb power armored infantry, their equipment and support (a whopping 24,000 lbs or about 12 tons of an 84 ton craft(empty)).
Now if there are vast amounts of ocean or large amounts of rivers or roads, I say go for it and beef up your GEV!
There are no benefits for removing ATT, DEF or RNG unless you strip it down to almost nothing (tactically useless), then would it then go as fast as 5/4. Who needs a racing GEV on a battlefield unless as a scout anyways?
So, A GEV as this one:
MOV: used to be 4/3, now is 2/2.
7 vp or around 1 armor unit. This thing is like a Light Howitzer with long a lot of mobility.
Have I broken the GEV/artillery mechanic?
Make it move OR shoot?
Have it lose a movement point in order to shoot?
I don't know... so many questions.
MOV: use to be 4/3, now is 2/1. (just as heavy as a heavy tank with weakness and strengths!
5.7 vp or just 1 armor unit. Although this better than a Heavy Tank over water and rivers, try using this GEV Tank in forest or have it survive a cruise missile blast...
I don't know, add 50% to the vp cost if it's a GEV and goes beyond 4 att, 4 rng, and 4 def and still retains it's speed?
GEVs are meant to be cheap and expendable. If they become tanks on skids, we are looking at another tech level jump into Hammer's Slammers territory here. I think Steve Jackson meant for the GEV to be a light raiding type of vehicle, not one that breaks the tactics of the game.