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MPG

diesel_lv

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1967 Coronet 440 4dr. 383 stroked to 496. 727 auto w Gearvendor o/d, 3.73 gears n 26.5" tires. Fitech FI. Cruising at 60mph, 2,400 rpm, 11 mpg. That is the best so far. Usually 8-9 mpg
 
1967 Coronet 440 4dr. 383 stroked to 496. 727 auto w Gearvendor o/d, 3.73 gears n 26.5" tires. Fitech FI. Cruising at 60mph, 2,400 rpm, 11 mpg. That is the best so far. Usually 8-9 mpg
Well we didn't buy them because they are good on gas, now did we?
 
Gotta keep the oil industry going before we lose it! I’d check your air / fuel ratio and if it’s good and the spark plugs look good leave it and accept it , enjoy it don’t worry!
 
Wow. Seems to me that with the overdrive and the fitech, i should be better than that. Might just be a function of 496 inches. Taller tires? Just be glad you're not paying california gas prices.
 
That's not so bad. My parent's new stock 1971 383 Road Runner with 3.23 rear end only got 12.5 MPG (3000 RPM @ 70 MPH).
 
I don't even bother checkin' my 472.
 
It's the extra doors, otherwise you'd be getting 20.
 
440, edelbrock performer heads, torker intake, hughes cam, 355 rear, 727 and 28" tires 10mpg cruising.
 
66 Charger 387, 906 heads, .455 mopar cam, weiand intake, 68-69 Exhuast Manifolds H-pipe, 727 with 3:23 rear
Running MSD atomic
Honest 14.5mpg at about 60-65. AFR set to 15 I think.
When it was completely stock with the 500 CFM AFB I actually got almost 17 on one trip. (a long time ago...)
 
'70 Coronet, 505cu, Indy LEZ heads, Indy dual plane, Mighty Demon 850, hughes cam, 3.55 gears, 27inch tires, about 1000 smiles per gallon :thumbsup:
 
I don't think you could even smile 1000 times in 5 minutes.
It's simply not possible.
 
That's about normal for full size autos from that era---they were all gas pigs
 
My current ‘64 Sport Fury, 426W, 3310, stock magnum cam, 3.23, auto. 12.5 mpg.

Previous ‘70 coronet r/t 440, 830 Holley annular discharge, 284 purple shaft, 3.55, 4-speed. 8 mpg

The most obvious difference I’ve found between these two is vacuum advance. Makes a huge difference. The coronet had a mechanical only Mallory, came in fast but never went into the 50’s for cruising. Wouldn’t have hit 12.5 even if it did but might have been 11. Also worth checking your odometer vs gps. Probably wrong. Speedo probably isn’t calibrated right when odo is and vice versa.
 
1967 Coronet 440 4dr. 383 stroked to 496. 727 auto w Gearvendor o/d, 3.73 gears n 26.5" tires. Fitech FI. Cruising at 60mph, 2,400 rpm, 11 mpg. That is the best so far. Usually 8-9 mpg

I have never done a cruise on the freeway only gas mileage check, but I don't think it gets much better than my "mixed" driving. I always get at least 11 and some times over 12. 508 cuin, 3.23 w/ automatic, 950 carb.

I think if I tried to get good gasmileage, I could get another 1 or 2 mpg with what I have.
 
Just for reference, when I drove across country in 2015 I got an overall average of 17.2 MPG for the whole trip. My MPG was likely higher, but my fuel vent design was bad so I was spitting fuel out my vent when I filled it up.

Specs: 1970 Road Runner with original 383 - not rebuilt. Added headers and 2.5" exhaust, around 82,000 miles at the start of the trip. I added fuel injection and we drove with a .73 A-833 overdrive. 3.55 rear.

Agree - we don't buy these for the fuel economy, but I was impressed that it got this good mileage. And we did NOT baby it to get the 17.2 MPG!
 
Fuel mileage complaints with 496 cubic inches?

REALLY?!?!

:rofl::rofl::rofl: :wtf:

What cam do you have in there? Specs!!!!!!
Run the FI as lean as you can.
 
I don't think he is complaining. I think we is sharing info and that the mileage is moving in the right direction with the EFI.
 
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