matt852

What are your rpms like at 80mph with what gearing and hows the gas mileage? Looking to build the jeep to my needs which will involve long cross country interstate driving at 70mph - 80mph frequently. I want to collect all the trail badges on the jeep app.

Thanks,

Matt

Wrangler22

I have a 2011 JKU 3.8L, AirAid CAI w/tb, 5.13 gears and running a 37's. I drove somewhere around 400 miles and averaged 17.1 driving 75 mpg on cruise control.

MrChuckles

I have a 3.8 on 37s and a 6speed and I'm not sure it can do 80mph. lol! I think I've hit 80 in 5th gear, but I haven't regeared and don't plan on it because I'm replacing the axles.

Biginboca

JKU with 3.8L 6 speed, 5.13 gears, and 37's. I get about 3k rpm at 80 and at that sped about 9-10mpg. Daily driving I get about 12mpg with 50/50 city/highway driving. I actually get better mileage city at like 14mpg.

I have a snorkel, heavy foot, and a lot of mods (see profile) including a Performance tune so my mileage is probably a worst case scenario.

Ajkaz

07 JK 3.8 6 Speed. At 75 mph I'm roughly at 2800 RPM with 4.88's and 37's. Before the Ripp I averaged 15.5 mpg, after Ripp I average 17 mpg if I keep acceleration moderate. Not sure what tire your running or plan to run, a lighter tire will make a significant difference in mpg on the hwy. The BFG KM2 & KO2, Courser MXT, MTR are all very light 37's, they are lighter than most Nitto, Toyo & Cooper MT 35's!

matt852

Thanks for the input everyone I plan on running the 37 stt pro which are light for a 37 but everyone I have talked I said they come in mounted at a 35.5-36.5.

karls10jk

I've got some 37" stt pro tires that I can go measure for you. It's an extreme, but 3.73 gears will put you into probably 13mpg range at 80mph. I know she's not a happy camper at 70ish and that's needing to stay in 5th. I *may* be able to bolt them on and get an exact rpm but they're tight on my setup.

matt852

Thanks Karl always there whenever I have questions haha.

Biginboca

Coincidentally that is the tire I'm running. I have the 13.5" width if it matters.

karls10jk

Late reply but I finally got them on- 36 1/8" on 17*10 racelines....and these are the 13.5" width. I will not be taking them up to 80mph.