8 mpg!!??
Printed From: The Ford Torino Page
Category: Model Specific Forum
Forum Name: 1977-1979 Ford and Mercury
Forum Description: Technical discussion for 1977-1979 Ford and Mercury
URL: https://forum.grantorinosport.org/forum_posts.asp?TID=3427
Printed Date: 26-March-2026 at 3:24PM
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: 8 mpg!!??
Posted By: Turbo301
Subject: 8 mpg!!??
Date Posted: 15-April-2010 at 4:24AM
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I finally got around to doing a mileage check on my '77 Cougar: ouch! In all-city driving, I'm getting only 8 mpg, and that's out of a 302! Yes, it's a LOT of stop-and-go, but I really expected double-digits, at least.
Any thoughts? ------------- 1977 Cougar XR7 1980 turbo Trans Am 2009 Pontiac G8 GT |
Replies:
Posted By: Psquare75
Date Posted: 15-April-2010 at 7:36AM
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Define "all city". With a light foot and mostly highway/ 40 mph back roads, I get 10.8 with my Cougar.
Um, you sure your speedo is accurate?  ------------- Paul 77 XR7 460/C6/3.00:1 *SOLD* 78 XR7 523/C6/3.5:1 79 F100 460/TKO500/3.25:1 'I also have some left over potatoes-I understand you can generate electricity from them'- Foote500 |
Posted By: Turbo301
Date Posted: 15-April-2010 at 7:58AM
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All stop-and-go, 30-40 mph speeds. And yes, my speedo is reasonably accurate... or else the cop behind me last night was very generous :).
I think I have a pretty light foot, although I do have to step into it a bit to get any sort of acceleration like I'm used to. ------------- 1977 Cougar XR7 1980 turbo Trans Am 2009 Pontiac G8 GT |
Posted By: Psquare75
Date Posted: 15-April-2010 at 11:15AM
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>although I do have to step into it a bit to get any sort of acceleration
like I'm used to< There's your problem. ------------- Paul 77 XR7 460/C6/3.00:1 *SOLD* 78 XR7 523/C6/3.5:1 79 F100 460/TKO500/3.25:1 'I also have some left over potatoes-I understand you can generate electricity from them'- Foote500 |
Posted By: Turbo301
Date Posted: 15-April-2010 at 11:40AM
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That would hurt that much, eh? ------------- 1977 Cougar XR7 1980 turbo Trans Am 2009 Pontiac G8 GT |
Posted By: occupant
Date Posted: 15-April-2010 at 12:08PM
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Geez. I've got an oil-burning, noisy valvetrain 351M in a heavier '76 Gran Torino sedan and I've gone 150 miles on a third of my very first full tank so far but it's probably more like half a tank thanks to the fuel gauge curve. Either way I'm probably pulling 13mpg minimum and I'm thinking more like 15 or 16.
But 80% of my driving is going 62mph on dry pavement. The rest is gentle driving because the more I put my foot in it, the more oil it burns. At 80mph I appear to have a blown head gasket. Under 50mph there's no smoke, but I can't drive that slow out here in the country unless I'm painted IH red, JD green, or Ford blue. ------------- 15 Cruze LT, 145K, for the wife 08 Uplander LS, 280K, broken again 08 Explorer EB, 248K, backup work car still looking for another something |
Posted By: BIGEMUN
Date Posted: 15-April-2010 at 2:43PM
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Hmmm- gummed up carburetor, dirty air filter , fouled plugs, bad wires, old cap/rotor/coil, and bad gas might be worth looking into as causes? ------------- 1975 Gran Torino Sport |
Posted By: Turbo301
Date Posted: 16-April-2010 at 2:16AM
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Changed/serviced all those things except the wires and cap/rotor, which look fairly new. I might get some new wires anyway, though, as the set on there now is one of those "universal fit" kits that really doesn't universally fit :).
------------- 1977 Cougar XR7 1980 turbo Trans Am 2009 Pontiac G8 GT |
Posted By: Psquare75
Date Posted: 16-April-2010 at 2:49AM
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I'm sure if my 460 was stop and go in the middle of the city, it'd be much less than 10. Try filling the car and going 'on a run'. backroads, high way, that kind of driving. You should see around 17-18. ------------- Paul 77 XR7 460/C6/3.00:1 *SOLD* 78 XR7 523/C6/3.5:1 79 F100 460/TKO500/3.25:1 'I also have some left over potatoes-I understand you can generate electricity from them'- Foote500 |
Posted By: BIGEMUN
Date Posted: 16-April-2010 at 2:50AM
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Maybe your axle ratio? Also check if you have a vac. actuated flap on your exhaust for cold starts to see if it opens after warming up. ------------- 1975 Gran Torino Sport |
Posted By: Psquare75
Date Posted: 16-April-2010 at 2:54AM
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Bigemun, there's a guy on mercurymuscle.net who regularly gets 15-18 MPG from his cars, and he daily drives them, stock setups. A 302 should have 2.75s. It should get better than 8 MPG.. I think it's either his driving habits (What do you let the car shift at?) or.. his route/traffic.
------------- Paul 77 XR7 460/C6/3.00:1 *SOLD* 78 XR7 523/C6/3.5:1 79 F100 460/TKO500/3.25:1 'I also have some left over potatoes-I understand you can generate electricity from them'- Foote500 |
Posted By: occupant
Date Posted: 16-April-2010 at 3:03AM
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There's a pair of mixture screws on the front of the carburetor. According to some Jeep/Bronco boards, they should be 1.25 to 1.5 turns out from seated. When I got my car, they were a good three or four turns out. So seating them and then backing off a turn and a half on each made a difference, exhaust has no smell now except for burning oil, etc... ------------- 15 Cruze LT, 145K, for the wife 08 Uplander LS, 280K, broken again 08 Explorer EB, 248K, backup work car still looking for another something |
Posted By: Turbo301
Date Posted: 16-April-2010 at 3:03AM
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The traffic has been terrible, no doubt about that (hitting EVERY red!) I'm not that aggressive a driver, honest! But the car seems quite hesitant to accelerate up to speed; it's okay going from one speed to another, but from a stand still it's pack-a-lunch time :). I just figured that was a function of the gutless 302, but maybe it's not supposed to be THAT gutless? It idles nicely, and starts right up... unfortunately since I cleaned the carb it no longer goes to fast idle, it just goes immediately to low idle. Once it warms up and the choke lets go, though, it runs fine.
Blargh, so much to go funny on a car LOL! ------------- 1977 Cougar XR7 1980 turbo Trans Am 2009 Pontiac G8 GT |
Posted By: Psquare75
Date Posted: 16-April-2010 at 3:07AM
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http://video.google.com/videoplay?docid=4161105945085313481# This is my 351W with 3.5:1 rear gear. Your 302 shouldn't pull anywhere close to this, IMO. ------------- Paul 77 XR7 460/C6/3.00:1 *SOLD* 78 XR7 523/C6/3.5:1 79 F100 460/TKO500/3.25:1 'I also have some left over potatoes-I understand you can generate electricity from them'- Foote500 |
Posted By: GranTorinoMan
Date Posted: 16-April-2010 at 3:39AM
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I would pull the distributor and make sure it's dialed with the right advance curve first. Pick a gas you fill up with most of the time and tune your car to it, I've got my 472 set up for Shell 87 (bronze). With the correct advance you can play with the Carb to get the right fuel ratio for max economy and power.
http://www.carmemories.com/cgi-bin/viewexperience.cgi?experience_id=232 - http://www.carmemories.com/cgi-bin/viewexperience.cgi?experience_id=232
http://www.fordmuscle.com/archives/2007/06/AirFuel/ - http://www.fordmuscle.com/archives/2007/06/AirFuel/
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Posted By: occupant
Date Posted: 16-April-2010 at 2:28PM
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If you want to play with the dizzy, and hesitation throughout the power band is a damn good reason to figure out what the ignition system is doing, read, read again, and read a third time, this post:
http://www.carbdford.com/viewtopic.php?t=5543 - http://www.carbdford.com/viewtopic.php?t=5543 Tells you ALL you need to know about the Duraspark setup. You want to tune it right, that thread is the place to be. ------------- 15 Cruze LT, 145K, for the wife 08 Uplander LS, 280K, broken again 08 Explorer EB, 248K, backup work car still looking for another something |