42 mpg in a TJ

[bohuggabee]

Ok. Thanks guys. Update. I still havent fixed it. The engine runs colder without bypass. But 11$ in coolant every 3 months is ridiculous and the fumes lol. As you would expect. 163,000 miles now, but god damn i live this jeep. The pressure calculations are for overflow of the coolant for whomever asked. Heat and less fluid and less circulation means more pressure. More pressure results in corrosion. Anyway. I try my best with it. I try to know everything about it. Im quite capable but resources for self care of vehicles are almost dried up in the real world and guys like us are going extinct.

I know... im a type that tries to figure it out on my own. Someone stabbed my tank and stole my fuel, the day after i just filled up lol. I patched it with jb weld and a really dense woven cloth i soaked with the jb weld. 2 years its held. I think that part of the fun of a analogue jeep. Is trying to solve issues creatively. Of course i cant bypass sensors or whatever. But ive been able to get 42 miles per gallon in my 99 jeep 4.0. Which is unheard of.

 

[chili_pepper]

ive been able to get 42 miles per gallon in my 99 jeep 4.0. Which is unheard of

It is, for a reason.

 

[Rickyd]

I know... im a type that tries to figure it out on my own. Someone stabbed my tank and stole my fuel, the day after i just filled up lol. I patched it with jb weld and a really dense woven cloth i soaked with the jb weld. 2 years its held. I think that part of the fun of a analogue jeep. Is trying to solve issues creatively. Of course i cant bypass sensors or whatever. But ive been able to get 42 miles per gallon in my 99 jeep 4.0. Which is unheard of.

 

[Link]

 

[tr21triton]

But ive been able to get 42 miles per gallon in my 99 jeep 4.0

OH YES, the miracle of a FRAM oil filter !!!

 

[Artsifrtsi]

It is, for a reason.

I got that in my Gladiator last summer… I filled the tank in Breckenridge, CO, and stopped for the night just south of Denver…

 

[bohuggabee]

Thanks guys. You were intelligently useless

 

[bohuggabee]

OH YES, the miracle of a FRAM oil filter !!!

So idk what that is. All i know is i figured it out on my own. From analyzing my jeep and what could be wrong.

 

[chili_pepper]

Thanks guys. You were intelligently useless

Sorry, I'm not playing this bullshit...

Not sure what your deal is here, but I think the responses are commensurate with your postings. Clearly you don't think so, but we could start with that 42 mpg claim from a 4.0L I-6 AMC engine. How do you expect anyone to take anything you say seriously?

Your original heater core question was addressed very clearly many posts ago by a number of users. Do the bypass like others do, replace the core or deal with the coolant odors and window fogging. NO sensors to bypass, no pressures to worry about. Oh, and invest in a damn hydrometer to check the specific gravity of your coolant so you don't have issues in the future, they cost a buck or two at your local parts store. 50/50 mix, no more, no less. And use the correct damn coolant.

And now you're rambling like you forgot to take your meds and smack talking others. You're either a troll or really damn thick. Either way, you can go pound sand up your ass as far as I'm concerned.

 

[bohuggabee]

Sorry, I'm not playing this bullshit...

Not sure what your deal is here, but I think the responses are commensurate with your postings. Clearly you don't think so, but we could start with that 42mpg claim from a 4.0L I-6 AMC engine. How do you expect anyone to take anything you say seriously?

Your original heater core question was addressed very clearly many post ago by a number of users. Do the bypass like others do, replace the core or deal with the coolant odors and window fogging. NO sensors to bypass, no pressures to worry about. Oh, and invest in a damn hydrometer to check the specific gravity of your coolant so you don't have issues in the future, they cost a buck or two at your local parts store. 50/50 mix, no more, no less. And use the correct damn coolant.

And now you're rambling like you forgot to take your meds and smack talking others. You're either a troll or really damn thick. Either way, you can go pound sand up your ass as far as I'm concerned.

Im not joking. I averaged 32 and got up to 42. I focused for a month to get that. 12 miles of driving a day. Using my torque band. Im very proud of it. I drove nearly a month and a half on 25$

 

[bohuggabee]

Sorry, I'm not playing this bullshit...

Not sure what your deal is here, but I think the responses are commensurate with your postings. Clearly you don't think so, but we could start with that 42 mpg claim from a 4.0L I-6 AMC engine. How do you expect anyone to take anything you say seriously?

Your original heater core question was addressed very clearly many posts ago by a number of users. Do the bypass like others do, replace the core or deal with the coolant odors and window fogging. NO sensors to bypass, no pressures to worry about. Oh, and invest in a damn hydrometer to check the specific gravity of your coolant so you don't have issues in the future, they cost a buck or two at your local parts store. 50/50 mix, no more, no less. And use the correct damn coolant.

And now you're rambling like you forgot to take your meds and smack talking others. You're either a troll or really damn thick. Either way, you can go pound sand up your ass as far as I'm concerned.

Since youre so smart. What was my average rpm? Difference between a troll and me. I drove 12 miles a day for nearly a month and a half with 25$ in gas... can you reduce and calculate the cost of fuel for 42 mpg?

I can

 

[Rickyd]

Sorry, I'm not playing this bullshit...

Not sure what your deal is here, but I think the responses are commensurate with your postings. Clearly you don't think so, but we could start with that 42 mpg claim from a 4.0L I-6 AMC engine. How do you expect anyone to take anything you say seriously?

Your original heater core question was addressed very clearly many posts ago by a number of users. Do the bypass like others do, replace the core or deal with the coolant odors and window fogging. NO sensors to bypass, no pressures to worry about. Oh, and invest in a damn hydrometer to check the specific gravity of your coolant so you don't have issues in the future, they cost a buck or two at your local parts store. 50/50 mix, no more, no less. And use the correct damn coolant.

And now you're rambling like you forgot to take your meds and smack talking others. You're either a troll or really damn thick. Either way, you can go pound sand up your ass as far as I'm concerned.

Enough clowns have been run off of this site that I suspect it's a troll thinking they are taking us for a ride.

Guy could just be a moron but it would take a lot of talent to be that simple.

In either scenario the joke is on them

 

[bohuggabee]

Enough clowns have been run off of this site that I suspect it's a troll thinking they are taking us for a ride.

Guy could just be a moron but it would take a lot of talent to be that simple.

In either scenario the joke is on them

Answer the question.

What was my average rpm? Difference between a troll and me. I drove 12 miles a day for nearly a month and a half with 25$ in gas... can you reduce and calculate the cost of fuel for 42 mpg. Can you calculate my average speed with the rpm? You wont even ask what my tire circumference is lol. Let alone know why you should. Am i right?

Or go away

 

[Cooper Smith]

Ok. Thanks guys. Update. I still havent fixed it. The engine runs colder without bypass. But 11$ in coolant every 3 months is ridiculous and the fumes lol. As you would expect. 163,000 miles now, but god damn i live this jeep. The pressure calculations are for overflow of the coolant for whomever asked. Heat and less fluid and less circulation means more pressure. More pressure results in corrosion. Anyway. I try my best with it. I try to know everything about it. Im quite capable but resources for self care of vehicles are almost dried up in the real world and guys like us are going extinct.

You do know the radiator cap regulates system pressure, right? That's why there's a spring on it. It vents and regulates at a certain PSI. Your heater core delete is doing nothing to the regulation of pressure/cooling in your Jeep. My truck's heater core comes out with a few bolts under the dash and it's right behind a cover. Muahahaha.

And man, $11 in coolant for 3 months? My shitty 2.4 leaked a quart of oil in two weeks. Feel sorry for the poor bastard that owns it now.

@Rickyd Am I insane here? I've never seen someone overthink something like this. Is the rad cap the red-headed stepchild or something, or am I completely wrong about cooling systems?

 

[Link]

Answer the question.

What was my average rpm? Difference between a troll and me. I drove 12 miles a day for nearly a month and a half with 25$ in gas... can you reduce and calculate the cost of fuel for 42 mpg. Can you calculate my average speed with the rpm? You wont even ask what my tire circumference is lol. Let alone know why you should. Am i right?

Or go away

 

[Jamison C]

Next we’re gonna find out he can do 60MPH in 4L.

 

[KennethS]

Another great story told in a thread about overheating. 80 psi rated radiator cap.

Lol funny. Cause we got a after market “oem” cap from o reilly. Rated to 80 psi. Wouldnt seal. The original cap was clearly of high quality. But too. The radiators wear. I have to compress and set the cap on the tabs instead of proper setting lol. Ruins the springs over time but seals.

Definitely an automotive genius as evidenced by this:

Post in thread 'Jeep was overheating when sitting idle'

May 4, 2025

It is possible your fan clutch may be bad, sitting idling with no air/ not enough air moving through radiator, vs driving with air being forced through…

Wtf is a fan clutch?

• bohuggabee

• 
• 

 

[DuckNut]

Here is your answer:

Calculation cant be done because you have not furnished enough information. What injectors you have? What fuel rail pressure is? What your ecu is programmed at?

So based on the lack of necessary info lets use stock. Stock flow rate is 236cc/min.

Your 42 mpg story is bullshiz and you forgot to add in the extra fuel you forgot to use in the calculation.

 

[Rickyd]

You do know the radiator cap regulates system pressure, right? That's why there's a spring on it. It vents and regulates at a certain PSI. Your heater core delete is doing nothing to the regulation of pressure/cooling in your Jeep. My truck's heater core comes out with a few bolts under the dash and it's right behind a cover. Muahahaha.

And man, $11 in coolant for 3 months? My shitty 2.4 leaked a quart of oil in two weeks. Feel sorry for the poor bastard that owns it now.

@Rickyd Am I insane here? I've never seen someone overthink something like this. Is the rad cap the red-headed stepchild or something, or am I completely wrong about cooling systems?

You got it right. Its a sent here to entertain us.

The guy navel gazing about his 2wd convertible jeep comes in a close second

 

[bohuggabee]

You do know the radiator cap regulates system pressure, right? That's why there's a spring on it. It vents and regulates at a certain PSI. Your heater core delete is doing nothing to the regulation of pressure/cooling in your Jeep. My truck's heater core comes out with a few bolts under the dash and it's right behind a cover. Muahahaha.

And man, $11 in coolant for 3 months? My shitty 2.4 leaked a quart of oil in two weeks. Feel sorry for the poor bastard that owns it now.

@Rickyd Am I insane here? I've never seen someone overthink something like this. Is the rad cap the red-headed stepchild or something, or am I completely wrong about cooling systems?

No. The overflow is for that. The cap seals. It says its for a specific psi, but after market caps now are ridiculously cheap in quality. Borderline junk actually. My original spring failed on mine.