I don't think you'll have any "ill effects" on your car. I use it in alot of my vehicles, in alot of different areas. Engine oil...standard trans...differential etc... I have a 67' Chevrolet pickup with a lifter noise (valvetrain in engine) and did an oil change with Lucas...no more noise and oil pressure is back up where it belongs.Also a good concept..."ain't broke, don't fix it". And with 240k and no problems...you're doing something right.my .02Crowldog