You have explorer ships.
You have trade ships.
If you give a tradeship a decent range when it's hauling all the cargo (so that it doesn't make hauling terrible), it has uber-range when not hauling cargo.
If you give a tradeship a decent range when it's not hauling cargo (so that it doesn't compete with explorer ships), it has an abysmal range when it's hauling cargo.
Solution: MAKE CARGO WEIGH LESS (Do a handwavium thing, new tech that's now standard on cargo containers). REBALANCE ACCORDINGLY.
You have trade ships.
If you give a tradeship a decent range when it's hauling all the cargo (so that it doesn't make hauling terrible), it has uber-range when not hauling cargo.
If you give a tradeship a decent range when it's not hauling cargo (so that it doesn't compete with explorer ships), it has an abysmal range when it's hauling cargo.
Solution: MAKE CARGO WEIGH LESS (Do a handwavium thing, new tech that's now standard on cargo containers). REBALANCE ACCORDINGLY.