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What can you reasonably expect for fuel economy?

I get around 12-13 with a stockish 426W. If you care about this stuff it’s a really good idea to check your odometer over some distance (like that 100 mi) against GPS doing the same thing. Even with the “right” gear in the tranny the odometer can be pretty wrong. I “lost” 1.5 mpg when I did this correctly.
 
My odometer hasn't worked since I bought the car, so heck-if-I-know. Hoping to get that squared away sometime this Summer.
 
A few trips I've done with Hot Rods. Stock 68 383 Dart GTS 4 speed 3.23 245/60s, 14mpg. 73 Challenger, 370" sb, Holley 650 DP, [email protected]" cam, 4 speed, 2.76 gear, 275/60, 18mpg. 64 Fury, 440' max wedge intake, 2 750 Eddy's , [email protected], 5 speed manual w/od, 3.55, 275/60, 14mpg. All stock AMC 327 Vigilante V-8 powered Jeep Gladiator pick-up, 3.90 axle, 9.00-16.5, 9.5 mpg. 2020 Challenger Scat Pac, 22.5mpg
Doug
 
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This thread should be combined with one that asks about what you should expect from marriage.
 
When I was daily driving my A12 to work, I would have been ecstatic with double digit anything. 7 or 8 mpg at 70mph/3700. 4.10 gears, and a Sixpack, don't you know.
 
When I was a 20 year old kid, I bought my '69 Charger. I still remember my mum telling me "you'll be able to pass everything...but a gas station".
 
Kern Dog said:
Sorry, I edited the post to include the overdrive fifth gear.
Final drive in OD is 2.27 to 1.
Click to expand...
Boy, don't that help a bit! :)

You know, it's funny - back when, we never really were want for an overdrive gear in these critters....
not that I can remember, anyways.
Society now has had entire generations of vehicles that came with O/D transmissions and we're all so
used to them now that these old cars damn near demand one from us now, though.
The automatics are one thing (and to me, boring as hell) but cars I've had like the '89 5.0 Mustang
with the T-5 B/W though - you could enjoy banging gears in that thing (first through fourth were PARTY
GEARS) and then pop it into 5th (O/D) when it was time to chill and cruise. :thumbsup:
 
My 67 with the low compression 76 ,440 , mild comp cam and Tquad.
3.23 gear , AT, & 26" rear tires.
65-70 mph on 100 mile round trip gets
11 to 12 mpg..
 
HawkRod said:
Fuel mileage is something that will affect me a a lot on my trip across country.

In my 2015 trip my 383 based (stock engine with a FAST fuel injection system) 70 Road Runner, with a .73 overdrive averaged 17.2 MPG for the whole trip. That included half the trip when we pissed fuel out the vent after filling the tank (the vent was not set up properly).

For my trip starting next week, I will be driving my 73 Road Runner with a 340 based stroker with 416 cubic inches, a 727 with a Gear Vendor's overdrive (.78 OD). I am running a Thermoquad carburetor from a 400. We will see what I get; I will be happy with 15 if I can get it. With high gas prices and an estimated 10-11,000 miles for the trip, fuel is going to be expensive, so every MPG counts!
Click to expand...
Wow, I can't even fathom getting 17mpg out of one of these things. That's pretty darn impressive, given their
construction!
 
Nate S said:
I get around 12-13 with a stockish 426W. If you care about this stuff it’s a really good idea to check your odometer over some distance (like that 100 mi) against GPS doing the same thing. Even with the “right” gear in the tranny the odometer can be pretty wrong. I “lost” 1.5 mpg when I did this correctly.
Click to expand...
Yep, I went through all that speedo gear-swappin' stuff a few years back when I was getting ready to put
Fred on the road. Using the handy dandy Mopar chart, I got the right color gear to suit the rear tire size and
GPS confirms the speedo is pretty darn close! Probably closer than any previous old Mopar I've owned, really.
Wife and I were experimenting with that yesterday on my cell phone, in fact - just to verify.
(I have an app that does speed and such...)
 
moparedtn said:
Boy, don't that help a bit! :)

You know, it's funny - back when, we never really were want for an overdrive gear in these critters....
not that I can remember, anyways.
Society now has had entire generations of vehicles that came with O/D transmissions and we're all so
used to them now that these old cars damn near demand one from us now, though.
The automatics are one thing (and to me, boring as hell) but cars I've had like the '89 5.0 Mustang
with the T-5 B/W though - you could enjoy banging gears in that thing (first through fourth were PARTY
GEARS) and then pop it into 5th (O/D) when it was time to chill and cruise. :thumbsup:
Click to expand...
My recent inherited new toy... Can't wait.. Pic of the NEW TKX and rebuilt 302 going in it...
DSCF0014.JPG
DSCF0880.JPG
 
joe smith said:
I just looked up the Octane for the WaWa NON ethanol here and its 89? Does your car run OK on it?
Click to expand...
Heck no - not only does he run funny on anything less than 93, he's even wasteful of ethanol 93 - guzzles it
like it's going out of style.
The only gas he seems happy with is the "pure" 93 - he's real good about being a truth detector on the stuff
too.
Another regional gas station claims they sell "ethanol-free" gas, but Fred let us know in a hurry that they
were lying. :)
 
joe smith said:
My recent inherited new toy... Can't wait.. Pic of the NEW TKX and rebuilt 302 going in it...
View attachment 1274816 View attachment 1274820
Click to expand...
They make a nice transmission and it seems perfectly suited to the little Ford engine.
I constantly heard at the SCCA tracks about mine back in those days that "those T-5's blow up" and
"you'll be swapping burnt up 8.8 ring gears" and "3 races out of that clutch, tops".

Well, I sold the car several years later with over 250,000 miles on it - still with the original drivetrain
in it, never taken apart - and that car got beat like a rented mule every time we took it out.
That's the only non-Mopar I've ever owned in my adult life, too (and I ain't young).
*whispering*That '89 5.0 Mustang stands as the single best car I've ever owned - absolutely bulletproof!* :lol:
 
moparedtn said:
Wow, I can't even fathom getting 17mpg out of one of these things. That's pretty darn impressive, given their
construction!
Click to expand...
Our 66 Newport 383 would get 18 pulling our 15 foot aluminum boat to Canada.
 
Mine gets around 23 on the highway and once the go pedal is activated, it goes to who cares pretty quick. 5.7 with a little work done to it and an overdrive ram truck transmission. Almost the most fun you can have with your clothes on.
 
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