No combustion byproducts get into the tranny fluid so they aren't comparable. I've seen gm recommend 60k miles of towing. I'm nearing 170,000 and plan to at least check level and take a sample my tranny shifts perfectly and I push it but only have the six.

Wife's has given me some weird shifts but I think because I reset the adaptations so it could learn her behavior

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)