Okay, I've been working on putting together a new mission for my group based on an idea from MotX. The team will be sent to rescue an Inquisitor from a Tyranid warzone. The Inquisitor will be with several thousand survivors from a city that was recently overrun and will refuse to leave with the Kill-team; they'll have to escort the entire convoy to the safety of a nearby hive and its starport if they want to complete their primary objective.

That brings me to a piece of the 40k universe I'm not overly familiar with. What sort of power/fuel consumption do Imperial vehicles have? I'm not sure about the DW vehicles from RoB, but I remember reading that more basic vehicles like civilian haulers use promethium. That's great, but how long could such a thing last? Right now I'm expecting the trip to take about a week, and I already expected that I'd want to include the convoy having some sort of tanker vehicle or other means of refueling. Are there other power sources used? Any info on the subject would be appreciated.

I can't say for sure, but I'd be shocked if you found any hard info on how much fuel they might burn. The only practical way to do it would be to have fuel consumed at the 'speed of plot'. If it would suit your story to have vehicles run out of fuel, then they do and if not then they don't. Scavenging missions could be fun subplots for the mission, as could be covering the convoy as they stop to refuel from a tanker vehicle. 'Rolling refuel' operations could be fun as well, where the vehicles transfer fuel without stopping. The kill team would have to provide security for any of these vulnerable moments.

The fuel source only really matters for 'fluff' purposes. On a sophisticated hive world, vehicles might run off large power packs similar to those used by lasguns. Other worlds might use promethium (Which is essentially gasoline). It really just depends on the mood you want to set. Would you have a tanker truck, or a large truck hauling a portable plasma generator?

That's about what I expected. I was just hoping someone had seen some more definitive information on this stuff out there in one of the books or something. My initial thought is to use a promethium tanker of some kind. I'll probably not worry about the actual vehicles used by the team (I figure they've got more than enough power to last a few days since I've never read about them needing refueling), but I figured the civilian vehicles wouldn't get off so easy. Which, of course, just provides more challenges for the team to overcome.

If we're talking STC vehicles, then there are a variety of power plants that they might use. I personally tend to always assume that Astartes vehicles have fusion reactors and thus don't need promethium.

Promethium itself is very variable in quality, but fortunately Imperial military vehicles can run on pretty much anything from methanol upwards. I imagine that given very high quality promethium, they'll run much further than on 'normal' grade fuel.

ive definitely seen old fluff which states that rhino's can be adapted to burn wood for fuel, so essentially you can make the rules as hard or as vague as you want. I agree with siranui on fusion reactors with the additional statement that if the space marines have a vehicle it should be able to run itself almost indefinitely

I've run into this problem, too. My solution was to look up the fuel ranges of comparable modern vehicles on the interwebs, and round up (promethium being more efficient than gasoline).

If it's a matter of gas, well... bio fuel amidst a horde of scared civilians is probably not so hard to come by... xD

Silliness aside...

www.fas.org/man/dod-101/sys/land/m113.htm -> You might want to take a few notes from real world APCs as reference for the transports, if you go the promethium route. The link also includes details like speed and such, so you can set a time frame for your adventure.