The Official "My Gas Mileage *****" Thread

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lfhoward

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Air filter does nothing to improve fuel economy. NOTHING.

I've already explained that the throttle is what limits the amount of air to your engine more than anything. That's it's purpose, to restrict airflow to the engine. That's what's being "throttled".

A free flowing filter might allow a bit more air at wide open throttle, which is pointless to the discussion of fuel economy.

So, everyone enjoying recent fuel prices?
Not enjoying, no. Filled up at $4.459 yesterday and considered that price lower than most in my area (Philadelphia). But I am ok paying a bit more at the pump to not contribute to the Russian invasion of the Ukraine.

A couple of pointers:
The GasBuddy app has crowd-sourced maps of gas station prices, so you can find the lowest price in your area.
Lukoil stations have the lowest price in my area by 5 or 10 cents, but that is a Russian oil company. I will not get gas there.
 

Johnny O

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Surprisingly, my average 12mpg went up to 16 when the snorkel and Apollo were hooked up…even with the cyclone installed. As a caveat, I switched to ETOH free 87 too.
 

klc

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I get 12.9 to 14.9 with mostly in-town driving. I haven’t yet had the chance for a longer highway voyage. Going somewhere next week though, so I’ll be watching it. I’m getting the bat fuel injectors cleaned in a couple of weeks, and I still need to replace those bat spark plugs, but those are the last things on the to do list.

Still, after twelve years driving a four cylinder, it’s worth a few extra bucks to have an engine that can push me back in the seat, lol.
 

lfhoward

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It’s amazing how much old spark plugs can actually drag down mpg. Keeping them current (every 30K using the proper NGK copper core plugs) will save you money.

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lfhoward

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Surprisingly, my average 12mpg went up to 16 when the snorkel and Apollo were hooked up…even with the cyclone installed. As a caveat, I switched to ETOH free 87 too.
Too bad I never see ethanol free gas around here. I would want to do an experiment where I would see how much it increases my MPG, then see if that offsets the extra cost of buying ETOH free gas. Even if the cost was a little higher, it would probably improve performance. The environmental advantage of corn ethanol in gasoline is marginal at best and it probably actually increases emissions over regular gasoline. If it were ethanol made from switchgrass, then we would be getting somewhere environmentally.

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klc

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It’s amazing how much old spark plugs can actually drag down mpg. Keeping them current (every 30K using the proper NGK copper core plugs) will save you money.

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Right. I bought the car last July, so I have no idea what’s in there. I’ll reset the clock on plugs soon.
 

tssphoto

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Mine is an '04 Sport, 3.7L, auto. It only has 18,000 miles on it, sat most of its life. I'm only getting 13 MPG around town, haven't had it on the highway yet. I was thinking I should change the plugs and PCV valve, any other suggestions to increase MPG?
 

lfhoward

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I have a Scangauge II that lets me see the instantaneous and average MPG as I drive. It helps me see immediate feedback on how my driving style affects MPG, so it helps me drive in a more efficient manner.

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The Scangauge can display four gauges at once, as well as read and clear trouble codes. It is a handy device to have in the Jeep.
 
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TKJ

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Mine is an '04 Sport, 3.7L, auto. It only has 18,000 miles on it, sat most of its life. I'm only getting 13 MPG around town, haven't had it on the highway yet. I was thinking I should change the plugs and PCV valve, any other suggestions to increase MPG?
Tommudd here, hopefully you changed out all fluids in yours right away. That should help mileage some changing diffs, transfer case, transmission etc. Low mileage may seem great but it is the worst thing you can do to a vehicle. They draw in moisture just sitting. I drive a very hilly, twisty, curvy road 90 miles a day and get 19- 19.5 easy running it faster than most. But then keep mine refreshed, also it's lifted, bigger tires and regeared . That's on the 03. The 04 gets better, even lifted higher, bigger tires etc. It's easily gets 22 at 75 plus , going across Pa I got a smidge over 23 heading over to JBAs at 80 plus
 

TKJ

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I run scan gauges in all 3 of mine as well , but hardly ever use the mpg part
 

LONGJEEPOWNER

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21 miles to the gallon on highway but drops to 18 with the stop and go! 2010 Jeep Liberty with 3.7 everything stock. NGK plugs with Mobil 1 full synthetic oil.
Just drove from Pa. to S. Carolina. 180,000 miles on engine.
 

lfhoward

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21 miles to the gallon on highway but drops to 18 with the stop and go! 2010 Jeep Liberty with 3.7 everything stock. NGK plugs with Mobil 1 full synthetic oil.
Just drove from Pa. to S. Carolina. 180,000 miles on engine.
This is great. I used to have those numbers before lifting and running larger tires. Could get close to that again if I regeared to 4.10’s.
 

tssphoto

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So my 18,000 mile Libby uses lots of gas as I mentioned earlier, 13 MPG. It was owned by a little old lady who probably never drove over 40 MPH (my aunt) so I figured a new set of plugs wouldn't hurt. I bought the NGK V-Power OEM plugs and to my surprise I removed Bosch Iridium plugs. I took it for a test drive around the block and noticed an instant increase in power. Would the Bosch have been using more fuel? I'm sure some independent shop talked her into those. As recommended by tommudd, I'm changing all the fluids this week, both diff's, transfer case and transmission.
 

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Liberty's don't seem to like any of the fancy plugs.

You mentioned the fluids - if you haven't planned on it you might want to add radiator flush to the mix. Make sure you use HOAT coolant. If a shop somewhere put those plugs in they might have put the wrong coolant in at some point as well.
 

3-LIB3RTYS-3

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Hello all.

Just did. Drive from Vegas to MT. 1800 miles round trip. Up grades, averaging about 82 mph. Stock tires, no lift. 2 people. 2 GSP’s and random bits of luggage and dog stuff.

Averaged 19.7 mpg.

Would like to find a way for a bit better fuel economy but at this point I’m thinking I’m towards the higher end of mpg output.
 

klc

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Hello all.

Just did. Drive from Vegas to MT. 1800 miles round trip. Up grades, averaging about 82 mph. Stock tires, no lift. 2 people. 2 GSP’s and random bits of luggage and dog stuff.

Averaged 19.7 mpg.

Would like to find a way for a bit better fuel economy but at this point I’m thinking I’m towards the higher end of mpg output.
I’m getting that kind of mileage on the highway myself. I’ve read here that I should change my upstream O2 sensors.
 
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