If anything, it protects the engine mounts. Lots of reports and posts on odyclub.com about mounts getting thrashed due to VCM activation.Jury is out for me on the tuner still...I'm more concerned with fuel dilution with the DI being it is a short tripper and I'm in a very cold climate. I can smell fuel in the oil during the winter, I'm giving M1 0W-40 a spin to see how it does on about a 9 month/4,000 OCI. One thing I noticed immediately after the change was that VTEC activation seemed less harsh, and as many find the engine has quieted down some. Not like that matters though as all you hear is the injectors anyways!