Basically the biggest question about GL-5 fluid seems to be: Can I use GL-5 fluids in applications that call for GL-4? Google “GL-5 vs. GL-4” and you’ll find lots of opinions on the subject. It’s no wonder why people are confused.

One of CRP Automotive’s Innovation Council members, Don Fields, has been their point person with the BIMRS group on this topic. Don’s the owner of Mr M Car Inc. in Farmingdale, New Jersey and a BMW specialist.

To answer this question, CRP asked an engineer from Pentosin to test their GL-5 fluid, which is their Double clutch transmission fluid called FFL-4. They ran two tests on both for comparison: one that measures the level of gear protection and a second to measure copper corrosion. To learn more about what CRP uncovered, watch this episode of “Inside the Brands”.

For copies of the test results you can email CRP at info@crpindustries.com