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View Poll Results: How many MPG can I haz?
5-7 0 0%
8-10 2 33.33%
10-12 2 33.33%
12-14 2 33.33%
Ignorance is bliss (still vote on your estimate) 1 16.67%
Multiple Choice Poll. Voters: 6. You may not vote on this poll

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Unread 04-07-2013, 10:31 AM   #1
revelc
Registered User
1985 FSJ Wagoneer 
 
Join Date: Nov 2011
Location: Tyler, Texas
Posts: 663
I am up in Colorado Springs (6,035ft) and will be heading to Ben Wheeler Texas (531ft) about 810 miles away.

Ill be driving my Wagoneer with the mods listed in my sig, and a fresh side pipe set up.

I'm still breaking her in so my speeds will vary
between 60-75 mph
A gear calculator with no variables gives me
2,210 RPM at 60
2,394 RPM at 65
2,579 RPM at 70
2,763 RPM at 75


How many MPG do you think the old girl will squeeze out with my 3.31 and 31" set up. I've heard the more power you have the less fuel it takes to push it down the road. And I've heard displacement has a price.

Chime in if you have a similar build and I'll post results when I return

My cam specs


Crower Part Number 45241

Lobe center 112
Advertised Duration: Intake / Exhaust 276 / 281
Duration @ .050" Intake / Exhaust. .212 / 220
Lobe Lift: Intake / Exhaust .290 / .305
Rocker Ratio: Intake / Exhaust 1.6 / 1.6
Gross Valve Lift: Intake / Exhaust .464 / .488
CID 390 401
Performance Level 2
Low RPM 1500
Peak HP 4000
Redline 5500

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Wag Rebuilt 360, 260H, 727, Locked 44, AMC 20, 208, 31" M/T's, 4" Rustys, 2.5" Duals. SOON:SOA SF, 496, T400, Doubler, D60's, 37" M/T's <-TOY
Cherokee Rebuilt 360, 2" Duals, mostly stock. SOON: Hot Street 401, 4'' Rustys, 33" BFG A/T's maybe a T-case to get rid of Q-Track <-TOW RIG
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Unread 04-07-2013, 10:37 AM   #2
RockRollin
"Positive.....I think"
 
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1990 FSJ Wagoneer 
 
Join Date: Apr 2012
Location: Grand Haven Mi, USA
Posts: 1,083
12-13 @ 65mph. Your cam is very close to my Edelbrock. With the 31" tires are you adjusting for the increased gear ratio. The stock is 28.5" tire
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"I like fun" Edd
Clawed: 90GW, TFI, Streetfire, 3"lift all spring, 31"BFG ATs, working RKE, Edel2131, Holly 1850, mild cam,
05 Renegade OME 927, 947, top plate, JBA 4.5s
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Unread 04-07-2013, 10:42 AM   #3
revelc
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1985 FSJ Wagoneer 
 
Join Date: Nov 2011
Location: Tyler, Texas
Posts: 663
Quote:
Originally Posted by RockRollin
12-13 @ 65mph. Your cam is very close to my Edelbrock. With the 31" tires are you adjusting for the increased gear ratio. The stock is 28.5" tire
I'm not sure what mean by adjusting sir.
__________________
Wag Rebuilt 360, 260H, 727, Locked 44, AMC 20, 208, 31" M/T's, 4" Rustys, 2.5" Duals. SOON:SOA SF, 496, T400, Doubler, D60's, 37" M/T's <-TOY
Cherokee Rebuilt 360, 2" Duals, mostly stock. SOON: Hot Street 401, 4'' Rustys, 33" BFG A/T's maybe a T-case to get rid of Q-Track <-TOW RIG
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Unread 04-07-2013, 10:51 AM   #4
RockRollin
"Positive.....I think"
 
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1990 FSJ Wagoneer 
 
Join Date: Apr 2012
Location: Grand Haven Mi, USA
Posts: 1,083
You have increased your "rolling gear ratio" with the larger tire by 7%. So in effect for every 10 miles on your odometer, you have traveled 10.7miles. While calcuating your mpg, multiply by 1.07 for your correct mileage. Cuz ya want every advantage you can get
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"I like fun" Edd
Clawed: 90GW, TFI, Streetfire, 3"lift all spring, 31"BFG ATs, working RKE, Edel2131, Holly 1850, mild cam,
05 Renegade OME 927, 947, top plate, JBA 4.5s
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Unread 04-07-2013, 10:52 AM   #5
revelc
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1985 FSJ Wagoneer 
 
Join Date: Nov 2011
Location: Tyler, Texas
Posts: 663
Quote:
Originally Posted by RockRollin
You have increased your "rolling gear ratio" with the larger tire by 7%. So in effect for every 10 miles on your odometer, you have traveled 10.7miles. While calcuating your mpg, multiply by 1.07 for your correct mileage. Cuz ya want every advantage you can get
Duly noted! I'll be sure to factor that in. Thanks Rock.

I was just going to go off of the mileage on my GPS for accuracy.
__________________
Wag Rebuilt 360, 260H, 727, Locked 44, AMC 20, 208, 31" M/T's, 4" Rustys, 2.5" Duals. SOON:SOA SF, 496, T400, Doubler, D60's, 37" M/T's <-TOY
Cherokee Rebuilt 360, 2" Duals, mostly stock. SOON: Hot Street 401, 4'' Rustys, 33" BFG A/T's maybe a T-case to get rid of Q-Track <-TOW RIG
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Unread 04-07-2013, 10:57 AM   #6
RockRollin
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1990 FSJ Wagoneer 
 
Join Date: Apr 2012
Location: Grand Haven Mi, USA
Posts: 1,083
Quote:
Originally Posted by revelc View Post
Duly noted! I'll be sure to factor that in. Thanks Rock.

I was just going to go off of the mileage on my GPS for accuracy.
Well yea I guess that works too
__________________
"I like fun" Edd
Clawed: 90GW, TFI, Streetfire, 3"lift all spring, 31"BFG ATs, working RKE, Edel2131, Holly 1850, mild cam,
05 Renegade OME 927, 947, top plate, JBA 4.5s
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Unread 04-15-2013, 06:56 AM   #7
revelc
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1985 FSJ Wagoneer 
 
Join Date: Nov 2011
Location: Tyler, Texas
Posts: 663
7.82 MPG'S on the way from Colorado to New Mexico
It improved to a little over 8 as elevation decreased.
1,000 pounds
78-80 MPH sometimes speeds up to 95
832 miles
6,100 feet drop in elevation.
__________________
Wag Rebuilt 360, 260H, 727, Locked 44, AMC 20, 208, 31" M/T's, 4" Rustys, 2.5" Duals. SOON:SOA SF, 496, T400, Doubler, D60's, 37" M/T's <-TOY
Cherokee Rebuilt 360, 2" Duals, mostly stock. SOON: Hot Street 401, 4'' Rustys, 33" BFG A/T's maybe a T-case to get rid of Q-Track <-TOW RIG
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