small block performance AND economy

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I've run into tight times with money. So I cheated. Bought a 93 Mustang 5.0 5 speed. I get 17-18 mpg around town and 25 mpg on the highway cruising@ 75 mph. It handles,stops and have power everything. Plus it's a blast to drive. If it was a Mopar it would be perfect. I wish I could afford a new Challenger but I can't. And to spend the money on updating an older Mopar gets crazy money. I'll be using my Dart just for real world fun at cruise nights and shows.
 
I got 19mpg highway if I drove my '68 dart easy. had a 340, .550 solid lifter cam, 9.5:1 pistons, thermoquad, X heads, adjustable rockers out of a 273, headers, 4spd h.d. clutch, 3.23:1 gears in the rear.

the problem is people will take a 318 and put heads from a 360 on them, lowers the compression ratio to 7:1, then run an automatic (non lockup converter of course), a mech secondary double pumper holley and then expect mileage? LOL aint gonna happen.

cam has less effect than your compression ratio. quickest way possible to ruin the mileage is by plopping the wrong heads on and a big hog of a carb.
 
moparlover said:
I got 19mpg highway if I drove my '68 dart easy. had a 340, .550 solid lifter cam, 9.5:1 pistons, thermoquad, X heads, adjustable rockers out of a 273, headers, 4spd h.d. clutch, 3.23:1 gears in the rear.

the problem is people will take a 318 and put heads from a 360 on them, lowers the compression ratio to 7:1, then run an automatic (non lockup converter of course), a mech secondary double pumper holley and then expect mileage? LOL aint gonna happen.

cam has less effect than your compression ratio. quickest way possible to ruin the mileage is by plopping the wrong heads on and a big hog of a carb.
Click to expand...

FWIW, my mileage did not drop signifigantly going from 318 heads to 360 heads. Yes compression makes a difference but not a gigantic one.
 
For a few years I was making the trip from a Brandon to Winnipeg Manitoba every week-end. The distance was exactly 200km one way with a gas station right at the edge of each city, so every time I would make trip I would fill up both ways and keep track of my milage. The best the older mopars that I drove could get was my 170 slant 67 Valiant stripper 3 on the tree car was around 23 mpg, this is at 65mph.
My 318 2 barrel cop car would pull 22mpg, this was with headers, full duals, electronic ignition conversion 2.94 gears and synthetic oil in everything. Plus it was lowered a bit from stock.
 

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I got about 12 with my 340 dart. 850 DP on a single plane high rise.11:1 compression .507 solid cam, Hooker SC headers with 2.5 exhaust all the way back, 3200 stall and 3.91 gears with a 225 60 15 on cop wheels out back with space saver rims and vw size tires up front. Now if I'm on it, that's a different story and it drops to about 4 lol.
Tuning, tuning, and more tuning!
Now I get none since I split the block :(
 
I currently average 15 mpg with my 360, mostly city with a fairly heavy foot lol... very similar to dgc333's build but i have a milder cam, big killer for me is the crummy (loose) 2500 stall converter on my 904 combined with stock 2.76 gears. I have a tighter converter ready to swap in hopefully it'll give me a couple MPG... if i had a manual trans i bet i could push 20 pretty easy. Not to mention the exhaust needs some work it's definitely restrictive off the shorty headers and leaking lol
 
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