That is VERYYYYYY high. There isn't a strong consensus on what the best ratio for this stat is. Technically it just has to be >1, which means you are making +EV river calls.

If your river call efficiency is THAT high, that means that you are folding in a lot of spots that you could otherwise be calling. Remember, even facing a river pot size bet you only have to be good 33% of the time. So a call that is correct 40% would be losing majority of the time but still the correct call.

Again this is a cash game specific perspective. This might be different in sng's, given you don't get that money back once you lose it. so maybe a river call efficiency of 2.53 isn't sooo bad for tourneys, but I have no clue.