One of Mercury Racing’s most loved power packages, the 525EFI looks to have gone the way of the flip phone as Mercury Racing evolves forward with a new version to be recognized as the 540EFI. The new engine features their popular digital throttle and shift feature. While Mercury Racing did increase displacement from 502CID to 523CID aiding in the increased horsepower output they also claim to have increased additional torque by over 10% basically adding another 50ft lbs of torque. Best of all this engine is designed to run on the lowest of grade fuels 87 octane.
So we could just give you the reprinted jargon about how the engine uses the latest in Mercury’ racing 555 ECU technology, cylinder head advancements, CNC machine engine blocks, and so on; but there is more to the story and if you have followed the industry for very long you know that the 525EFI had one of the most restrictive intake manifolds ever and this is was what lead Mercury Racing to add dual throttle bodies to create the 565EFI
What the press pack doesn’t acknowledge is this engine features an entirely new intake system similar to the new 520EFI engine we are huge fans of. I would be willing to bet money these engines perform much better than their modest rating. These engines will bring another generation of performance enhancement opportunities to the aftermarket as well.
Either way Mercury Racing has just improved an all ready incredible power package, and if that wasn’t enough they have taken a cue from the aftermarkets demand of a shorter lower outdrive offering. Now the engine can be ordered with a new 2″ Shorty lower unit Bravo One XR stern drive featuring a dual water pick up. Not to mention after all of that Mercury Racing dropped a redesigned logo to public as well.
