I have a 1966 Ford Mustang Coupe with a 200ci straight 6-cylinder engine with a 1V carb.
Can anyone give me some tips on getting the best gas mileage out of my car?
I am currently getting 14 MPG (city) / 16 MPG (highway), which I think is terrible.
Are there any gadgets that can improve my MPG?
Any ideas would be greatly appreciated!
Thanks,
Jimbo
I don't know what the flow rating is on your carb but you need in the neighborhood of 290 cfm for your engine to breathe correctly. The old thinking of smaller carb-better mileage is nonsense. The engine requires a certain amount of air at any given rpm and if the carb is too small it will run rich and burn more fuel than necessary.
Then you need to check your timing because most factory settings are conservative and bumping up your timing can usually help. Make sure you have a clean air filter and no restrictions in the air intake track. Changing the jetting on the carb will reduce fuel consumption as long as you don't lean it out too much. Finally you need to adjust your tire pressure to the recommended level or slightly above to achieve minimum rolling resistance. All these things should help you attain better fuel mileage but all these things are to no avail unless you intend to drive like a mega-miler (read little old lady).
I've Googled to find out what the original fuel mileage was for your car, and struck out. However, here is what I did to a '78 jeep wagoneer to get the mpg up to what the last year wagoneers were getting,,,, Cold Air Intake! My jeep originally had a flexible hose running from the aircleaner snorkel, to the fender, which the previous owners had discarded. I bought the Wagoneer in around 92 for 400 bucks,,,, After they had sunk it at a boat landing in louisiana. I replaced the 4 barrel Carter? carb, ( the engine was a 360 V8), that the previous owner mangled the metering rods in, trying to remove the water, with a holley 600 4 barrel carb. However, gas mileage sucked. Setting the timing to factory settings got me spark knock, Until I reinstalled an air intake hose to the air filter. Once that was done, I could run the spark timing required, and get 13 mpg on the highway. Considering it weighed around 4200 lbs, and was fulltime 4 wheel drive, I thought that was pretty good.
If you could rig up a CAI to your airfilter, and readjust your spark timing, you should get better MPG. Assuming the engine is in good shape.
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1989 2.3 Stealth Red (old cheap paint) LX Hatchback
2007 4.0 Torch Red Coupe
Jimbo, the first thing you need to do, is figure out what kind of condition the engine is in..!
Have you done a compression check, and are all holes within about 15% of each other? Is the distributor in good condition, or is the timing all over the place between cylinders? You can check that on an old-fashioned distributor machine... Assuming that the engine is in good shape, then you need to have it properly tuned. I'm sure some mechanics still know how to do that, but you may have to look around to find one, or do it yourself. If the engine is in need of rebuilding, the best way to improve mileage (and up power), is to rebuild it with a higher compression ratio. About 10:1 is as high as you'll want to go using pump super. High compression really improves both torque and economy; it's a win/win, assuming you don't mind running super gas. If doing a rebuild, also look into a very mild performance cam. If you don't go overboard here (choose wisely!), you can gain power as well as fuel mileage. For ignition, if your stock distributor is worn out, look around for an electronic replacement. Mallory used to do a Unilite for it, but you can probably just convert a good stock type to electronic with a Pertronix (used to be Perlux). I'm sure other electronic conversions are also around... A good long tube header and free breathing exhaust is another area to look into for increasing mileage. Not sure if anyone is still offering new ones for the straight-6, but there used to be good ones around (I remember Clifford Research 6=8). Maybe you can find a good used one at a swap meet? Anyway, check out the condition and state of your stock engine tune, for starters...
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'08 Bullitt -Highland Green
'09 GT-500KR -Black/Black
A lot of stuff that people to to make thier cars faster also makes the car more efficient increasing gas mileage. My 69 mustang with a 302 gets 16 on the highway and it has a aftermarket intake, holley650 carb, headers, exhaust, low profile tires and its lowered. And the heads on my motor are burning oil. higher compression pistons, Port the heads, intake, header, exhaust, muffler, pertronix ignition upgrade will increase mileage. Lowering the car about 2 inches will drastically lower wind resistence.
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69 Mustang, 302, 650 holley, edlebrock performer, hedman headers, flowmaster 40s, cooper tires, mustangs plus suspension, kh disc brakes.
Pony Carbs is the way to go. They blueprint the carbs. If you have a factory air cleaner setup change to an open filter. I also agree with ditching the points in your distributor. The Unilite would be a good choice and run an aftermarket coil. Definitely have the condition of your engine. Their are shops that specialize in rebuilding and hotrodding the old sixes. I would check websites because I know there is a good one out there. A friend of mine has a 66 coupe 3-spd manual that gets better mpg than you. Something else would be to see if someone makes an overdrive conversion for the straight sixes. My Dad has a 69 ragtop manual 3-spd 302 and his mileage has dropped since the addition of 10% ethanol. Pony Carbs can update your carb to run with todays fuel as well.
Yeah bud that is bad, my bros 65' with 289 is all stock other than intake and carb, he gets 15mpg with more power. Have you rebuilt it? Sorry if thats already been asked i didnt read what everyone wrote.
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1969 Mustang Mach 1
White/ Black interior
351 Windsor 430rwhp
FMX Trans
1966 Ford Mustang improving gas mileage 
