I have some Nitto Trail Grapplers (2000 miles) on my 2012 JKU now and getting horrible mileage, 15.5-16 hwy. One tire alone weighs 72 lbs. The Terra Grapplers (same size, 285-65-18) weigh in at 52. Could it be justifiable to sell the trail grapplers for a lighter tire? How much difference would a negative 80lbs of un-sprung weight make. They look awesome but the JK will probably see very little trail time. Thanks for the help fellas.

 

Rotational intertia is over 3x more detrimental as static inertia (at the given radius). Pulling 80 lbs of rotational inertia up to 50 mph or whatever speed, is similar to adding roughly 300 lbs to your vehicle during acceleration, so it will effect city driving more than hwy given this. You also have more rolling resistance that has to be overcome constantly. AND more leverage which could hurt depending on what gears you have.

 

Do you have a pro cal? I like my Nitto Trail Grapplers (35s) and get between 16-17 depending on how I drive during the week. I've found once I break 70mph the mpg suffers tremendously.

 

3.73 in the pumpkins. Might try to keep around 65 next trip. Who buys a Jeep for the mileage anyway?

 

what he said. rolling resistance will do more to hurt your mpg than slightly heavier tires.

 

Are you running with OD on? If yes, turn if off. You should gain a couple MPGs. I get around 18.3 hwy, driving at 60mph with cruise control, 35s Goodyear MTR/K. I also have a Superchips running 87 tune, but I doubt it does much other than set the tire size.