Does the stock Sport gearing return better MPG at 70mpg on a mostly flat highway with cruise on? Stock is 3.21 and the option is 3.73?

 

19 mpg on stock JKu Sport 2012 6 speed with 3,300 miles on the average reading =]
I drive with cruise control usually at 55mph

 

I do mostly city with a few quick stents on the highway. The computer reading (which has been fairly accurate when compared to doing the math) says 14.5 MPG overall. I do live in the NE so the colder weather will have a slight negative baring on the MPG.

I have a stock JKU Sport S with 3.21 AT. I wanted to see something closer to 16-18 in the city but we'll see what the summer brings.

 

Logic will say that the 3.21 will get slightly better mpg's. However I have yet to find anyone on these forums that thinks 3.21 is better overall than the 3.73. At least several people with manual trans have said the 3.21 makes 6th gear kind of useless. I have the 3.73 and am so glad i ordered that option. Also, at 70mph I think the poor aerodynamics of the jeep overshadows the gearing effect. The Prius does not really get good mileage because of the hybrid, it is more about the shape of the vehicle. Put a gas only engine in the Prius and the mpg will almost be the same as the hybrid. Seems like most cars targeting the fuel efficient market are gravitating to the Prius-like shape.

 

Rubi manual, 4:10, ~8K miles. Average since new is 18.8mpg - primarily highway commute.

 

I get around 16-17 mpg. My jeep has 33" tires , "2 inch ome lift", auto trans and 3.73 gears.

 

Rubicon 4 DR Auto, 4.10, stock tires with 2400 miles I get about 18MPG, mixed City and Highway 50/50 driving.

 

Good to know, that makes the 3.73 a must have upgrade in my book

 

Buy a car if you are worried about good MPG.

 

2012 JKU Rubi 4.10's 3" lift and 35's... 15-16mpg.