Cruise Control 80mph @ 2500rpm

ChrisLiberty · **Joined:** Wed Jun 18, 2008 1:48 pm **Posts:** 13

Had my liberty just over a month now and we just got back from our first trip. It was about 250 miles to the beach for us. Just wanted to check and see if 2500rpm sounds right for 80mph.

daspes · **Posted:** Sun Jul 06, 2008 4:24 pm

Not sure I haven' had my libby that high in a long time, since gas was about 1.29 a gallon. I keep it between 60-65 now. Just did a 1900 mile trip last month. On one fill up averaging 70 I was getting 15 MPG, at 65 it was 20... I keep it slow now.

Cobalt-60 · **Posted:** Sun Jul 06, 2008 4:29 pm

Yeah, that is about right for stock (215s or 225s). I had been running it up in that speed range (most Interstates in GA are posted 70MPH and you will get run over if you are not doing 5-10 MPH faster than that) until last month. I agree with Mike, when I go up to the LOST ECS in August, I am going to set the cruise at 65, sit in the right lane, and take my time.

myjeepwalks · **Posted:** Sun Jul 06, 2008 4:38 pm

ChrisLiberty wrote:

Had my liberty just over a month now and we just got back from our first trip. It was about 250 miles to the beach for us. Just wanted to check and see if 2500rpm sounds right for 80mph.

Yeah that sounds about right. Like others said with the price of gas i've slowed down a bit myself. $100 per week in fuel just to go to work is starting to piss me off.

DryBones · **Posted:** Sun Jul 06, 2008 6:34 pm

65 mph gets me at just around 1900 rpm's which I find gets me my best mileage. once over 2000 rpm's it goes down fast.

InCommando · **Posted:** Sun Jul 06, 2008 8:09 pm

Years & years ago, someone posted that the 3.7L was "most efficient" at about 2,200 with efficient meaning a balance of power & consumption. Not sure it even relates, but it sounds cool.

ChrisLiberty · **Joined:** Wed Jun 18, 2008 1:48 pm **Posts:** 13

I averaged 19mpg! Is that because I'm still totally stock?

daspes · **Posted:** Sun Jul 06, 2008 8:17 pm

Yep, lift it and put bigger heavier meat on the corners, and the MPG's will go down.

Jeepjeepster · **Posted:** Sun Jul 06, 2008 9:54 pm

I hand calculated 18.6 with my 3" lift and 245/70/16 tires on 06 moab rims. I did not take into account the small amount of error the larger tires cause either(around 10 miles per tank).

Speed limit varies from 55-70mph with many hill climbs on that tank.

My engine is running right around 2500rpms at 80mph and 1800rpms at 60mph.

durangotang · **Posted:** Sun Jul 06, 2008 9:58 pm

These things'll go 80? I'll have to try it sometime :lol:

tjkj2002 · **Posted:** Sun Jul 06, 2008 10:17 pm

My engine is turning just a tad over 2800 rpm's at 80 mph(actually 2825 +/- 20 rpm),my speedo is correct(+/- 2mph).I'm running 265/75R16 Trxus MT's(31.9" tall),4.10 gears,still way under geared for the tire size(4.30 gears would be right on),and the 45RFE tranny.I get 19mpg at 78-80mph in my KJ,better then 20-21mpg on the flat lands(10mpg in town

!).

You guy's running the 42RLE have a higher OD ratio so you will have slightly lower rpm's at a set speed then a KJ with the 45RFE,but I'll keep the 45RFE for it's strength compared to the 42RLE.

Cruise Control 80mph @ 2500rpm

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