I have spoken with the redline and royal purple people and, of course, they don't suggest using an additive but the people at Lubegard do suggest it. The folks at Redline suggested their D4 product for the Subaru SVX and were worried that the Lubegard could cause the fluid to be too slippery and cause excessive seal swell. The folks at Lubegard semi-agreed in that they suggested against their HFM product in the black bottle as it may contain too much friction modifier. However, they insisted that their product (they suggested the red bottle) only conditions seals and does not swell them. Lubegard also claims that their additive could decrease ATF temperatures by as much as 40F. I also know first hand that the red bottle is very good at keeping the clutch plates in Subaru center differentials from binding. So, I would think seal conditioning, lower operating temperatures and protection against differential binding would be a good thing. I am leaning towards Redline D4 with Lubegard in the red bottle. What do the experts here think?
On the topic of oils, I read something that implied that ester based products have more cleaning power than PAO based oils. Is that true based on your knowledge? As such, I would think using Redline and Royal Purple would create an even stronger need for seal conditioning, in addition to their inherent seal swelling, to prevent leaks.
On the topic of oils, I read something that implied that ester based products have more cleaning power than PAO based oils. Is that true based on your knowledge? As such, I would think using Redline and Royal Purple would create an even stronger need for seal conditioning, in addition to their inherent seal swelling, to prevent leaks.
