I have three truck bays, one at each wash for the past 21 years. It depends on how much truck traffic you get to make a decision about price. If the bay does not produce, charging more would only pay for the cleanup problems / mess. However, if the trk bay in your opinion does bring in extra revenue, charge more. I am currently $1.50/3min in all bays trk and car. My problem is the height of the car bays 11'6". It's great for the rec. vehicles, but it also attracts dumps, cabs overs, rollbacks etc., even though there is a trk bay at each location. The only way it would work for me to charge a different price, would be to somehow lower the car bay entrance/ exit. Until then, charging more will only lead the trks into the car bays for the lower price. If I lower the height, I would charge double for the truck bay, $3/3min or maybe even $5 for 5 or 6 min to start. That way I would at least get $5 for the mess.....