I was looking to do a drain-and-fill on my CVT for my 2015 Mitsubishi Lancer. Castrol's Transmax CVT fluid meets the "MMC DIAQUEEN Fluid J4" spec that is required by the manufacturer and is one of the most affordable options I can find that meets this spec.
As with any drain-and-fill procedure, a considerable amount of old fluid will remain in the transmission even when drained in areas such as the torque converter — my question is regarding the assurance that since Castrol's fluid meets manufacturer specs, that when the remaining OEM fluid and the new Castrol inevitably mix, there will be no ill effects on overall fluid performance (as in reactions between differing OEM and Castrol fluid chemistries).
I was told directly from Castrol that "Castrol cannot guarantee compatibility with competitive fluids as we do not know their proprietary formula, therefore we recommend a complete drain of the transmission and re-fill with CASTROL Transmax CVT Fluid."
Does anyone have experience doing drain-and-fills with differing brands of fluid? Was Castrol's response just the "safe" answer to go with? I paid a dealership $178 at ~37,000 miles for a drain-and-fill service (invoiced for 4qts fluid + labor), but the OEM fluid alone if I were to go the DIY route is $18.50/qt while Castrol's is $5.05/qt)
As with any drain-and-fill procedure, a considerable amount of old fluid will remain in the transmission even when drained in areas such as the torque converter — my question is regarding the assurance that since Castrol's fluid meets manufacturer specs, that when the remaining OEM fluid and the new Castrol inevitably mix, there will be no ill effects on overall fluid performance (as in reactions between differing OEM and Castrol fluid chemistries).
I was told directly from Castrol that "Castrol cannot guarantee compatibility with competitive fluids as we do not know their proprietary formula, therefore we recommend a complete drain of the transmission and re-fill with CASTROL Transmax CVT Fluid."
Does anyone have experience doing drain-and-fills with differing brands of fluid? Was Castrol's response just the "safe" answer to go with? I paid a dealership $178 at ~37,000 miles for a drain-and-fill service (invoiced for 4qts fluid + labor), but the OEM fluid alone if I were to go the DIY route is $18.50/qt while Castrol's is $5.05/qt)