Miles per gallon?

Leahatrill

Leahatrill

TJ Enthusiast
Joined
Feb 7, 2020
Messages
295
Location
Toronto
I forget how to do the conversion rate, but on a full tank of gas I get about 360km(combination of highway and city traffic) and this is with all four 02sensors not working properly LOL. The fuel and oxygen ratio is way off.

so question is: what’s the miles per gallon with a full tank giving me 360km? Lol.
 
Unless you're running the tank dry you're better off calculating by miles between filling the tank full, driving until low, and filling up to full again. Using the same gas station pump helps too if one clicks off sooner than the other.

For that to calculate: miles driven between both fillups / gallons filled.
 
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Leahatrill said:
That’s below average right? What’s the norm for most tjs with proper working 02sensors etc?
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All depends on your tire size and how much junk you have in the trunk.

My khaki TJ on 35s is 14mpg average.
My red LJ on 37s with a supercharger is between 10-13mpg.
 
Im in the Elevensies also. 37/auto/5.13 hilly country and mostly stop-n-go.
 
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Leahatrill said:
That’s below average right? What’s the norm for most tjs with proper working 02sensors etc?
Click to expand...

It depends, is the Jeep stock height with stock sized tires? If so, that's pretty far off what it should be. If you're running a lift and larger tires, it's still a tad low but not far off.

Mine with 35s is about 13-14ish
 
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I'm about 12mpg w/ 33s and 3.73 gears from a 5sp. I expect it will improve when I regear.

Edit: Forgot to add that my O2 sensors were replaced last year and my fuel trim numbers are where they should be.
 
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Tranz Zam said:
It depends, is the Jeep stock height with stock sized tires? If so, that's pretty far off what it should be. If you're running a lift and larger tires, it's still a tad low but not far off.

Mine with 35s is about 13-14ish
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I have 33s on a 2.5lift I think....I wonder when I fix the 02 electrical problem I’m having what the mileage will be then ...
 
Leahatrill said:
I have 33s on a 2.5lift I think....I wonder when I fix the 02 electrical problem I’m having what the mileage will be then ...
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When vehicles cant get readings from the o2s, they'll usually default to preset tables for fueling and airflow. Usually it'll richer up a lot in effort to protect itself from any damage that could happen from a lean condition.

In other words, without properly functioning o2s, the computer doesn't know what to do for fueling and dumps a ton in. Fix your o2 issues and you should see a noticable improvement.
 
Tranz Zam said:
When vehicles cant get readings from the o2s, they'll usually default to preset tables for fueling and airflow. Usually it'll richer up a lot in effort to protect itself from any damage that could happen from a lean condition.

In other words, without properly functioning o2s, the computer doesn't know what to do for fueling and dumps a ton in. Fix your o2 issues and you should see a noticable improvement.
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I haven’t had time to do it because of work and weather conditions lately — what’s the worse that could happen driving with all 02 codes on. The only thing I notice is resistance obviously ....and then sometimes as soon as I turn the engine off and then restart it within 5 min? In first gear taking off its sputtering like crazy — pcm trying to read the fuel/oxy ratio to deliver to the fuel injectors ....sputters like crazy for about 5 seconds and then registers ....
 
I’m at 13 to 13.5 or (5.74 Km/L Canadian) With 35’s and 5.38’s but I’m capable of making it worse.😉


edit: oops
 
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I was at 9-10 until Monday. Then I fixed the apparently 2 somewhat dead spark plugs. Now I'm at about 12-13 and a much smoother running engine. 33s with 4.10 gears on an 32rh and 4.0
 
Leahatrill said:
Spark plugs eh ....when was the last time you replaced them?
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Have you considered
SMILES per Mile ?
Sorry, but I couldn’t resist to throw that in
( no offence intended )
😂
On the highway I’m cruising at Max 55 mph or 88km/h with our 2005 LJ on COOPER Discoverer STT 33/12,5/15” and 5.5” lift
I’m always surprised about people who drive their JEEP’s at a 100+ km/h
 
Leahatrill said:
Spark plugs eh ....when was the last time you replaced them?
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I had them replaced 20k miles ago when I had an oil change done. I didn't trust that shop and thought maybe they were gapped wrong. But at 200k+ miles I figured I'd get a compression check and new plugs at a place I trust. To quote the shop new shop who I asked for a compression check at "two of the spark plugs crush washers weren't crushed". Then they said bring it back if new plugs installed right doesn't fix the loss of power issue and then they'll do the compression check.
That's what I get for trying to save time by paying for something I could do myself. Before that it was at least 50k.

I got a distinct feeling from that first shop that they didn't like Jeep's.
 
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