Was driving into strong winds with my 08 Unlimited that has 3" lift and 35 BFG/KM2 and couldn't keep my speed at 70mph. Had to keep spiking the speedo at 3000 plus Rpms and to keep speed I had to maintain it at 3000 RPM. Anything I can do to fix this problem?

 

What gears are you running?

Being that I'm still on stock 3.21 gears with 35s, I don't use 5th or 6th gear on the highway. I'm on 4th the entire time up to 75 MPH. I'm usually in the 2,600-3,000 RPM mark while on the highway to maintain speed.

 

Re-gearing is the only thing, short of a HEMI!

 

Drop down a gear....doesn't matter if you're auto or standard-top gear is overdrive,which is designed for flat surfaces and no headwind for fuel saving reasoning.
Remember when no vehicles had it? They had balls to spare.
Shift down 1 and you'll find the balls still exist but they're not the default setting
You'll probably notice that doing this will bring up your mpg's in hilly or headwind conditions.

 

I am running 3:21 axle ratio. Will upgrading my gears help? What should I upgrade to and how much does that cost?

 

I have an auto, but 5.13 gears for my 35s. I drove from Philadelphia to where I live (about 1.5 hours - 50-60 of it on highway) last night in the middle of a wind storm. I mean 20-30-40 mph winds. It's also hilly. Only moderate inclines, but still hills...

I put the cruise control on at 70mph and it didn't shift once, honest, the entire 50-60 miles I was on the turnpike. Winds, hills, nothing caused it to shift. Just rode at 2300-2500 RPM the entire way, depending on if I was climbining the hills or descending them.

While I was stock a few weeks ago, I did a similar thing (3.73 gears and 32s) and I had constant downshifting to maintain speed.

Gears are the best thing I've done...

 

Looks like that is what I need to. How much did that set up cost with install?

 

I run 4.88 with 35's, because mine is a daily driver and it dries perfectly. 70 miles an hour at 2000 rpms. It just purs down the highway and gets great gas mileage. You could see 1000-1500 bucks for the gears and install. Depends on where you get it done. Shop around, but you want someone that knows what they are doing.

 

So............ run it at 3,000 rpm on the odometer until you decide to up-shift. That, of course, unless you want to spend up to 3,000 on gearing. Three thousand rpm is right in the power curve.

 

The rate varies by geography. There are several threads that discuss the cost, but its somewhere between 800-1500.

With gears and Flashpaq programmer (`$300) the Jeep drives the way it should.