How many miles per tank

[superj]

When y'all fill up, how many miles do you get per tank?

My son took the 03 wrangler and drove to his first duty assignment in Colorado. He said he got 150-180 miles per tank, every tank.

That is horrible compared to the YJs the wife and I previously owned and compared to the jk four door we also previously owned.

The 03 got fresh trans fluid and oil the week before he left and all tires were air up properly. They are 32s and the gear was changed for the speedo/do to read properly. And it reads a exactly what my gps read so it's verified good.

He did drive normal highway speeds. Said he didn't like how the jeep felt at 80mph so he stayed at posted speeds the whole trip which was anywhere from 65-75.

His jeep had a pretty decent sized tank, I think 19 when I filled it up.

So he is getting pretty bad mileage. He has that 42rle trans so he has an extra gear, right? I would have expect a hair better than our YJs got, which the wife's stock 93 Sahara got 18 regularly and my stroked with a four barrel 87 got 13.

What do y'all get? He drove from south texas on the beach to Colorado springs so he got a few tanks in

 

[JPNinPA]

So what tire size, gear ratios, transmission?
The overdrive or the 42RLE is 0.69:1 which is really high and larger tires can lug the engine at 55-65mph. Lugging is harmful and running in very inefficient zone of the engine.

Then what speed and rpm does he cruse at?

In my 05 unlimited 3.73 rears and 33x9.5r15 with the 6 speed nsg 370 would get 18 mpg up to 20 if i hypremiled. Big thing is keeping it at 65 mph. Or between 60-65. Currently around town to work and home 290 mi/tank or app 15 mpg. That is more stop than go. App 9 lights and no faster than 35 mph. Engine hits temp in 1.5 miles or so.
Correct tire pressure and low to no ethanol gas. Properly aligned and balanced wheels.
Any added drag on the brick like offroad lights hood items, or bad pinion angles bad u joints or dragging brakes take away from mpg fast. Even things that inhibit natural cooling causing the fan to engage adds drag to the engine. Excessive power drain causes the alternator to run more and AC improperly charged or oiled is the same.


Also calculate mpg over a full tank dividing miles by gallons to refill from empty.


For reference on loading lugging the engine. Note you want to be at or slightly above 2500rpm


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[superj]

We will never know. He didn't keep fill up numbers. He can only give me rough numbers.

15ish gallons at each fill up and 150-180 miles per tank.

He has 32s with 3.73 gears. Said he drove 70-75 and had to turn off overdrive because of low rpms versus hills/mountains

 

[JPNinPA]

Yeah he would have to be going 83 mph in overdrive to be at 2250rpm. The bottom of efficiency. But you will not have the hp to pass. A breeze can slow you down. Actually don’t think the engine could get there unless down hill.

In third 2750 rpm to go 70mph. And 2950 to go 75 mph.

At 2550 rpm he should be at 65 mph in third. That would give the best mpg performance and keep from lugging the engine.

Then only use overdrive when on the flat or downhill when coasting to maintain speed.

This is all given the tires are really 32. As you know anything above 31 in diameter is called 32


Fyi wider and more aggressive tires drag more .

Never look down on anyone unless you are helping them up - Jesse Jackson

 

[southtj]

I have an 03 TJ, manual, 3.73 and 31 inch tires. I usually get about 180 - 200 miles per tank before I fill up and get 13 to 14 mpg for city only driving.

Has he had his spedo checked for accuracy since he got the bigger tires?

 

[Jeepergeo]

My '02 TJ gets 13 mpg on and off road, it would probably get that falling off a cliff while the engine is off.

'02 TJ Wrangler, Automatic, 4.11 gears, 33" tires on 15" rims, regular fuel, all calibrated. Generally I run no more than 65 mph on the freeway.

 

[superj]

yes, i checked his speedo using gps and following in my truck and his is dead on after we changed his speedo gear. his tires came out to 32.1 on the tire calculator using the metric numbers off the sidewall i don't remember the numbers though.

the tires are indeed wide and heavy but he loves that jeep now and has already sent pics of following trails around colorado springs. it sure is nice looking there

 

[JPNinPA]

What engine? I assumed I6 4.0 but I4s were an option.

You noted a 19 gal tank.
Mine is 19 but reads E when there is 2-3 gal left. Fill at E is 17-17.5 gal.
Run dry ~19.5 gal


Never look down on anyone unless you are helping them up - Jesse Jackson

 

[superj]

I am pretty sure we will never know now. At least until he drives it back on leave sometime. He is 4x4ing all around Colorado springs after work now so gas mileage is not going to matter anyways, ha ha ha.


It is a 4.0

 

[Andrew Mac]

Aloha!
A tad late to the thread, but my 2 cents on the miles per tank or miles per gallon. I have a 04 TJ, 4.0,33 x 12.5 x 15. Automatic Transmission.
For years I would go between 185/200 miles between fill-up's. That was a lot of Hawaiian driving, mostly slow, stop and go. Upon returning to the mainland. I replaced the stock, single nozzle Fuel Injectors with modern 4 nozzle injectors.
The milage has increased from 12ish MPG to better than 18 MPG. Money well spent, easy job!
Another factor I find with the TJ. Since it is a small, light weight vehicle. the amount of load I am carrying makes a big impact on mileage. Hauling around 600-800 lbs compared to only 250 lbs makes a big difference on the mileage. Running topless/doorless can yield almost 20 MPG with the reduced weight.
I 100% encourage all TJ owners to upgrade their Fuel Injectors.

 

[superj]

man, i haven't heard the continental usa called the mainland since i was a kid living in hawaii (oahu), ha ha ha. that was over 35 years ago. funny how some things never change

 

[Chilly]

I've noticed i get about 60-70 more miles in my JK in warm weather compared to cold. I was getting 10-11mpg when 35 or below but now with spring I'm getting 13-15 mpg in 65-70 degrees.

 

[Gennybro]

Aloha!
A tad late to the thread, but my 2 cents on the miles per tank or miles per gallon. I have a 04 TJ, 4.0,33 x 12.5 x 15. Automatic Transmission.
For years I would go between 185/200 miles between fill-up's. That was a lot of Hawaiian driving, mostly slow, stop and go. Upon returning to the mainland. I replaced the stock, single nozzle Fuel Injectors with modern 4 nozzle injectors.
The milage has increased from 12ish MPG to better than 18 MPG. Money well spent, easy job!
Another factor I find with the TJ. Since it is a small, light weight vehicle. the amount of load I am carrying makes a big impact on mileage. Hauling around 600-800 lbs compared to only 250 lbs makes a big difference on the mileage. Running topless/doorless can yield almost 20 MPG with the reduced weight.
I 100% encourage all TJ owners to upgrade their Fuel Injectors.

And take your tops off.

 

[JPNinPA]

Cold air is denser so more o2 .



Never look down on anyone unless you are helping them up - Jesse Jackson

 

[TJS27]

Was there any performance improvement as well?
I put on a 1” throttle body spacer and runs nicer now. 4.0 EFI.


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