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Rpm question

907 Views 7 Replies 5 Participants Last post by  firemansdiesel
I have read a few post saying they are around 1500 to 1650 rpms at 70mph. Mines is just over 1850. Is this correct . Hand calc on mpg is about 17.49. That's is over 5 tanks and 50/50 hwy/ city
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Thought I would add this is an auto trans.
It's is a 2500 with 3.42 gears. The tac reads just over the line between 1500 and 2000 so I am guessing 1750 to 1850.
My SRW with 3.42's turn 1500 at 70.
Is this manual or auto
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