Novak Conversions Jeep Wrangler TJ radiator

42 mpg in a TJ

srimes said:
I never trust people's mpg "estimates." Mileage is easy to measure, just measure it. Get the fuelly app, record gas added and odometer each time you fill up, and you'll soon have real data, and it even makes nice charts.

Here's my TJs average by month. Snow wheeling = terrible mileage :ROFLMAO:

View attachment 613894

here's my jeep's fuelly page
https://www.fuelly.com/car/jeep/wrangler/1999/srimes/1074365
Click to expand...

If you just knew the torque band and pitch of the road you could double that mileage. 🤣
 
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If we ignore all practical considerations, I do think it's probably possible to get 42 mpg in a stock-ish TJ.

Wind resistance increases with the CUBE of speed, and the aerodynamics suck anyways, so we'd want to keep the speed low. Probably around 30mph.

Gas engines are most efficient at relatively high loads, so we need to figure out how to efficiently apply a high load at a load speed.

Here's the plan: drive up a long, steep hill at 30 mph, turn off the engine and coast back down. No breaks as that's wasteful, and for max efficiency we'd want to be costing back down at about 30 mph as well, so the downhill run needs to be much more gradual than the uphill climb portion.

Find this perfect road, drive right, and you'll get amazing mileage.
 
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dcoop said:
Well, I'm getting screwed cause I have been running a K&N oil filter for over 10yrs and only get about 13.5mpg on a good day.
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You might wanna change that oil filter. 10yrs is too long on a filter….and maybe if you change it your fuel mileage will go up. Based on the posts here, probably need a Fram as it clearly makes higher mpgs…….

Just think, you too can get 42mpg with a new oil filter!!!
 
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DuckNut said:
So you start out in 1st or 2nd, get rolling and put it in 4th and putz along.
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I did that over a weekend up on the Mogollon Rim, driving FR-300 (dirt forest road) at maybe 30 MPH. We were the only vehicle on the road, so no stopping and starting for traffic, just steady cruising on a flat road with no hills. I got an amazing 23 MPG out of two consecutive tanks of gas. No way someone's gonna get 2x that mileage in essentially the same vehicle.
 
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Smokin42 said:
Nope. Lol I hate math. I will only do it if I need too. I do the guesstimate method. It is funny though I am tagged in here cause I have been trying to figure out how to increase it lately! Also, my O2 sensor been playing games with me.
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Well, welcome from South East Arizona. You've definitely found the best forum on the interwebs.
 
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srimes said:
If we ignore all practical considerations, I do think it's probably possible to get 42 mpg in a stock-ish TJ.

Wind resistance increases with the CUBE of speed, and the aerodynamics suck anyways, so we'd want to keep the speed low. Probably around 30mph.

Gas engines are most efficient at relatively high loads, so we need to figure out how to efficiently apply a high load at a load speed.

Here's the plan: drive up a long, steep hill at 30 mph, turn off the engine and coast back down. No breaks as that's wasteful, and for max efficiency we'd want to be costing back down at about 30 mph as well, so the downhill run needs to be much more gradual than the uphill climb portion.

Find this perfect road, drive right, and you'll get amazing mileage.
Click to expand...

So, if you coast backwards down the hill, will you get double milage? Asking for a friend who doesn't like to do math either 🙃
 
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bohuggabee said:
No wonder democracy fails by generational gaps. Instead of doing the math. You all come together to accomplish circle jerking? You are more people. Cant prove me wrong. Instead mock and troll. Youre worthless idiots
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I mock mock, and I mock mocks, which means I mock mock mocks. The 19th century called, they want their obsolete word back - but regardless, as soon as you started the ad hominum response, you lost.
 
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bohuggabee said:
No wonder democracy fails by generational gaps. Instead of doing the math. You all come together to accomplish circle jerking? You are more people. Cant prove me wrong. Instead mock and troll. Youre worthless idiots
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I did the math 236cc/ min. You have no idea how much gas you used because you only fill up to an unknown point and then guess at the mileage based on another random refill. You didn't do the math. You simply made shit up.
 
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Smokin42 said:
Nope. Lol I hate math. I will only do it if I need too. I do the guesstimate method. It is funny though I am tagged in here cause I have been trying to figure out how to increase it lately! Also, my O2 sensor been playing games with me.
Click to expand...

Read this thread and you too can get 42 mpg. Hell, join our club, we all get 42 mpg now...some even get more.
 
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KennethS said:
I did that over a weekend up on the Mogollon Rim, driving FR-300 (dirt forest road) at maybe 30 MPH. We were the only vehicle on the road, so no stopping and starting for traffic, just steady cruising on a flat road with no hills. I got an amazing 23 MPG out of two consecutive tanks of gas. No way someone's gonna get 2x that mileage in essentially the same vehicle.
Click to expand...

But you didn't find the mystery road that goes downhill both ways. No wonder why you only got 23.
 
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srimes said:
If we ignore all practical considerations, I do think it's probably possible to get 42 mpg in a stock-ish TJ.

Wind resistance increases with the CUBE of speed, and the aerodynamics suck anyways, so we'd want to keep the speed low. Probably around 30mph.

Gas engines are most efficient at relatively high loads, so we need to figure out how to efficiently apply a high load at a load speed.

Here's the plan: drive up a long, steep hill at 30 mph, turn off the engine and coast back down. No breaks as that's wasteful, and for max efficiency we'd want to be costing back down at about 30 mph as well, so the downhill run needs to be much more gradual than the uphill climb portion.

Find this perfect road, drive right, and you'll get amazing mileage.
Click to expand...

I’m right by pikes peak, maybe I will try that road. Brakes won’t work too well with the engine off though.
 
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srimes said:
If we ignore all practical considerations, I do think it's probably possible to get 42 mpg in a stock-ish TJ.

Wind resistance increases with the CUBE of speed, and the aerodynamics suck anyways, so we'd want to keep the speed low. Probably around 30mph.

Gas engines are most efficient at relatively high loads, so we need to figure out how to efficiently apply a high load at a load speed.

Here's the plan: drive up a long, steep hill at 30 mph, turn off the engine and coast back down. No breaks as that's wasteful, and for max efficiency we'd want to be costing back down at about 30 mph as well, so the downhill run needs to be much more gradual than the uphill climb portion.

Find this perfect road, drive right, and you'll get amazing mileage.
Click to expand...

Aerodynamics are not your friend.
IMG_0753.jpeg
 
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We use to mess with a guy at work by adding a couple gallons of gas each day at work to his tank. He was impressed and bragged about the fuel mileage all the time... then we cut off his supply... he nearly went craze thinking something was wrong all of the sudden...
 
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