I know a lot of people are going to argue here, but the Jeep manual recommends ATF in both. I run synthetic ATF in my 300 and it shifts great! Don't have the T5 anymore, but I ran ATF in that for 10+ years.
90wt in the 300 (do not use ATF!!!!) My owners manual says 90wt. Not sure about the T5 I ran 50wt racing oil in mine for three years and it was still fine when I swapped it out. Run what ever you want in the T5 you are not out much if it blows up anyway.
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