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Ive had a 2015 ed for 2 weeks now.i swapped the 265/70/17 for 275/60/20 goodyear wrangler sa.they are 1.31" taller than what it came with.when i get on the thruway the current mpg read on the dash drops to 20mpg.the slightest incline it drops 17.is the dash wrong due to the tire size or could i really be getting bad mpg with these slightly larger tires?and why only on the thruway?i wanted the 20" stock wheel upgrade but would i be better off switching the tires to a smaller diameter closer to what it came with?

I should also mention that i never drove the truck on the thruway prior to switching the wheels.i took it home and changed them the same day.im not familiar with the truck but it seems like on the windy roads to my house as soon as i hit a slight incline i have to push pretty good on the pedal just to try to maintain speed.maybe its a diesel thing?i am going to start towing a 20' enclosed trailer 5 days a week for work and i am worried what the mpg will be if its already not where it should be.im already at $80 in 2 weeks not driving far and babying the pedal.
 

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You went from a 31.6" tire to a 33" tire, so your gauges are telling you you aren't going as far as you actually are unless you got a tuner to adjust the calibration for the new tire size. Your shift points will be off too
 

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wrangler sa = Silent Armor ?


the *larger* tire diameter should actually help fuel economy a bit, due to the reduction in effective gear ratio..
BUT you raised the truck a smidge which will make your aero a bit worse..
more significantly you switched tire type from the SR-A to the SA .. that difference will cost you dearly in fuel economy.. I wouldn't be surprised if that was a 10% fuel economy reduction
 
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