currious on mileage

[Robyn]

My new to me 91 1500 Burb 4X4 has the 6.2 in it and along with that has 3.42 butt gears and the 700R4 tranny
The tires are 35-12.5x15
I am currious what sort of mileage others here with anything similar may be getting.
I have had 2500 Burb 4X that had 4.10 gears with stock tires and got 23 on the hwy and 18-20 around town.
This poor little 91 runs reeeeeeealy low rpms at cruise speeds on OD with them tall tires.
The 700 with its 3.06 low gear gets it rolling fine though.
Just currious what this thing might do. I am hopeing this thing will do as good on mileage as my 94 turbo did, maybe better would be nice

[moondoggie]

Good Day!

[indent]82 K1500 pickup, 6.2, New Process 4spd manual (4th is 0.70 (?) OD), 3.08 gears, 31-10.5x15 tires, PS, PB, no A/C, al topper

This truck ALWAYS got 26.0 to 27.9 mpg in the summer with its original (red) motor. On bad advice, I swapped in an 84 (black) motor. Subsequently it dropped 1 mpg or so. When I pulled it out of long-term storage a couple winters ago, I ran it from Nov through Feb or so. Every tank was 24

[doncannon]

Hello All,

Robyn: I am guessing if memory serves me well that with 35" tires it is not the stock suspession. I would guess you have a 6" lift? This could hurt mileage as there is more suspession for the wind to grab. Just food for thought and my 2 cents. I am curious about this also. I have my 2wd 3/4 ton and put 1ton springs on the front. I think this will hurt my mileage some

Don

[Robyn]

Its all of 6 inches.
3.42 gears dont help the cause. The majoic number for these engines seems to be 1800 RPM and getting there in 4th over aint gonna happen in this state and run any sort of legal speed.

[sidehackbob]

My 86 1/2T burb made 22-24 in the summer, them I needed new tires and bumped em up to 31s from plain ol 235s milage went below 20 & it killed the power. but the old dog sure looked cool.

[Robyn]

Power, Whats that???????????????????????/ :0)
With 3.42's and 36 inch diggers may 91 is a real dog but as you say it sure looks KEWL
PITA to get into for everyone that not 6' tall with long legs.
I have not tried to mount this beast yet wearing a skirt, not sure thats gonna even be anywhere close to Lady Like.
Looks like right now with the adjustment to the numbers to get the Odometer reading right its about 15 around town.
The Rpms really drop when it hits OD and Lockup.
60 is PUTT PUTT PUTT PUTT
PUTT
Doing the math it looks like around 1400 RPM at 60 mph in OD(3.42)
With stock tires it should be about 1600 rpm at 60 MPH (3.42)
With 3.73 gears it would be right near 1800 at 60
My 94 burb has these numbers on the tach
The other Burb with 4.10 runs right close to 2000 The math says 1918 but whos fussing with a couple revs
(These numbers are rounded off and not to the exact decimal I figured rolling circumference with Pi times the diameter and not actual real world rolling)
Beastly sized tires really make a BIIIIIIIIGGGG difference
Looking at the math again running my 91 in 3rd gear (Direct) with the 35 inchers would yield 1970 RPM at 60 MPH.
Possibly better for mileage rather than loafing it along.
Any speculation here ???????
Robyn

[moondoggie]

Good Day!

"Looking at the math again running my 91 in 3rd gear (Direct) with the 35 inchers would yield 1970 RPM at 60 MPH. Possibly better for mileage rather than loafing it along." I'd sure try it; I'd bet you mpg's will be better.

Blessings!
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