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-   -   Break-in MPG? (http://www.jeepgarage.org/f73/break-in-mpg-50980.html)

mufugger 11-30-2012 02:40 PM

Break-in MPG?
 
Hey everyone,

This is now my 3rd JGC. Started with a 2000, then a 2008, now in a 2013 black overland with saddle. LOVE it so far.

My only issue, 900 miles later is I'm getting terrible MPG's. In my 2008 4.7, I could get between 20-23 on the highway depending on whether I was going 65ish or 85ish.

With my 2013 5.7, I average about 17 or so highway, regardless of speed. I try hard to feather the throttle and trigger ECO mode as much as possible, but I can never get close to averaging the advertised 20 on highway.

Does it get better after break in? I know there's a lot of postings about this..but I guess I'm curious if this is what I should expect out of this vehicle, or if it will get better after break-in. Any thoughts/comments appreciated and welcome!

ColdCase 11-30-2012 02:58 PM

Re: Break-in MPG?
 
I saw a small increase at about 5000 miles. You need to use cruise control to get the best mileage. Fuel now days has so much more ethanol and perhaps water in it from time to time and station to station that its hard to make consistent comparisons.

SnoFire 11-30-2012 03:00 PM

Re: Break-in MPG?
 
I know in my wifes Hyundai that once you get over 80mph she isn't in ECO mode anymore.

GBJeep 11-30-2012 03:14 PM

Re: Break-in MPG?
 
I have owned mine a little over a year now and the mileage is not as advertised. Very happy with my Jeep, but this also depends on how much highway driving you do.

sly1types 11-30-2012 03:23 PM

Re: Break-in MPG?
 
I only have 2900 miles so I may not be the best source...

I got a little better now than when It did with less than 1k on it. I even got a highway tank at 17.5 mpg driving 78-80mph.

I have got 19-20, but I was only going 60-65 and trying to keep the eco light on.

Like someone else said I don't think the mileage is as advertised, but ohh well I really like the Jeep in all the other aspects.

mufugger 11-30-2012 03:46 PM

Re: Break-in MPG?
 
The thing that boggles my mind is that my 2008 4.7 was advertised at 19mpg highway. My 2013 5.7 was advertised at 20mpg, yet the highway mileage is worse? That's a bummer.

I love my new jeep, but that definitely seems a little bit misleading.

glassmtn 12-01-2012 03:45 PM

Re: Break-in MPG?
 
Have you checked fuelly.com? I imagine the V8s are somewhat accurate for overall mileage as they should all be 4x4s. The V6s may have some 2x4s mixed it.

eric.

JTS97Z28 12-01-2012 03:55 PM

Re: Break-in MPG?
 
I have logged every fuel fill up in my 2012 Overland V6 since new. I know you have the V8, but for what its worth I did not see much change in fuel economy from new to current mileage of 9,200 miles. I assume newer motors are built where things don't need to "loosen" up like they used to. Expect minimal changes at best. The Hemi is a great engine, but its not going to be spectacular on fuel economy so don't think your going to be getting 20mpg around town after some miles because you wont. It may improve some, but it wont be significant.
Good luck with the new Jeep and enjoy that thing, they are amazing vehicles!

James

SnoFire 12-01-2012 04:00 PM

Re: Break-in MPG?
 
Hopefully your not using E85... If you even can?!?

avalys 12-01-2012 04:53 PM

Re: Break-in MPG?
 
Tire pressures make a huge difference. The recommended Jeep factory pressures on my Overland with the ORA II package were 33 psi front and rear (18" tires). That's pretty low. I have been running 36 or 37 psi and it seems to do much better.

Remember that those are cold pressures. If you have to drive even a few miles to get to a filling station, your tires will not be cold. Tire pressure changes by about 1 psi with each 10 degF. It is hard to judge tire temperature with your hand. Best approach, if you don't have a compressor, is to measure the tire pressure before leaving and then make a note of how many pounds you need to add to each tire, and then add that much when you get to the gas station regardless of how the pressure's changed once you get there.

Similarly, if you fill up your tires with a compressor after the car has been sitting all night in your inside your 60F attached garage, and then go out driving in 30F weather, you will be down by 3 psi once the tires cool.

mufugger 12-01-2012 06:09 PM

Re: Break-in MPG?
 
You ain't kiddin about the tire pressure. I went out and saw all 4 tires were at 33psi. I have the 20" rims, the max psi is 51! That's how it came from the dealer..Filled up all four tires to ~50psi and went for a spin.

I did about 8 miles on the highway at 60ish and averaged about 26mpg! What a difference. That same stretch would have netted me about 17mpg before filling up the tires.

Thanks for the thought, what an amazing difference.

JTS97Z28 12-01-2012 06:48 PM

Re: Break-in MPG?
 
Quote:

Originally Posted by mufugger (Post 718314)
You ain't kiddin about the tire pressure. I went out and saw all 4 tires were at 33psi. I have the 20" rims, the max psi is 51! That's how it came from the dealer..Filled up all four tires to ~50psi and went for a spin.

I did about 8 miles on the highway at 60ish and averaged about 26mpg! What a difference. That same stretch would have netted me about 17mpg before filling up the tires.

Thanks for the thought, what an amazing difference.



Uhhh, you filled your tires to 50psi? :eek:

Please put them down to the recommended 36psi for the 20" wheels. DO NOT run at the max designed PSI rating...for the your safety and others. That means when your tires warm up your pushing probably 53+ psi. Not good!


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