I put on a little over 500 miles this weekend and so far have not noticed much if any change in fuel mileage. I'm running the smarty jr on sw1 and have an mp-8 that i'm running at 50%. I would like to run the smarty higher, but the clutch slips badly, which is kinda weird since my pickup only has 40k on it. I think since most all of my driving is highway the larger size and rolling resistance of the tires is made up for with the rpm drop at cruising speed???
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