Slant Six Forum :: Gas Mileage

: I know most of you here are not concerned with
: gas mileage, but maybe you can give me a
: fair evaluation anyway. I get a best of
: about 23 MPG with my 1980 Aspen. The car has
: a 1bbl 225, 904 lockup, 2.94 axle, recurved
: ignition and rejetted carb (slightly
: richer). Is this about what I should expect?
:
: Thanks

:
: Not Bad for a heavy car. To be honest, good
: racers "work" the same
: issues" we just take the improvement(s)
: in ETs and MPH instead of MPG. Do you know
: what your Aspen weighs "wet"? I am
: guessing it is close to 3800 may-be as much
: as 4,000 lbs.
:
: Other things to look at is less rolling
: resistance, (tire pressure at 36-38 psi?)
: disc brake , wheel bearing drag and even a
: higher rear gear ratio. (lower rato number
: like 2.76 but "around town MPG may
: suffer while highway MPG improves)
:
: Sounds like you have already found some good
: carb. jetting so that adjustment is not a
: good place to look for additional MPG. Think
: about ways to get some weight off the car
: and how it "pushes the air" at
: highway speeds. Getting the front end lower
: to the ground may help but watch those steep
: driveways.
: DD

: I do not know the actual wet weight, but I'd
: say a fair guesstimate is at least 3700 lbs
: with me in it. In so far as the axle ratio
: is concerned, I recently swapped out the OEM
: 14" tires for 15s. I calculate my
: effective ratio is now 2.67:1. Low speed
: acceleration has suffered, but highway
: cruising is better. Other things I did, but
: did not mention are: installed a fine wire
: mesh stainless steel screen under the carb
: for better atomization/distribution and I
: fabricated a coolant heated carb spacer.
:
: Mitch

:
: Did you check the calibration of your
: speedometer when you went to the 15"
: wheels? You may want to change your
: speedometer gear. It sounds like you may be
: going further than you think on each gallon
: of gas!
: Bob D

Author:	MitchB [ Thu Dec 13, 2001 9:58 am ]
Post subject:	Gas Mileage
I know most of you here are not concerned with gas mileage, but maybe you can give me a fair evaluation anyway. I get a best of about 23 MPG with my 1980 Aspen. The car has a 1bbl 225, 904 lockup, 2.94 axle, recurved ignition and rejetted carb (slightly richer). Is this about what I should expect? Thanks Mitch mb589@aol.com

Author:	Dart270 [ Thu Dec 13, 2001 11:35 am ]
Post subject:	Re: Gas Mileage
Quote: : I know most of you here are not concerned with : gas mileage, but maybe you can give me a : fair evaluation anyway. I get a best of : about 23 MPG with my 1980 Aspen. The car has : a 1bbl 225, 904 lockup, 2.94 axle, recurved : ignition and rejetted carb (slightly : richer). Is this about what I should expect? : : Thanks That is pretty much exactly what I would expect. 23 mpg is probably on the high side, actually. Lou

Author:	Doc [ Thu Dec 13, 2001 12:32 pm ]
Post subject:	Re: 23 MPG is pretty good
Quote: : I know most of you here are not concerned with : gas mileage, but maybe you can give me a : fair evaluation anyway. I get a best of : about 23 MPG with my 1980 Aspen. The car has : a 1bbl 225, 904 lockup, 2.94 axle, recurved : ignition and rejetted carb (slightly : richer). Is this about what I should expect? Not Bad for a heavy car. To be honest, good racers "work" the same issues" we just take the improvement(s) in ETs and MPH instead of MPG. Do you know what your Aspen weighs "wet"? I am guessing it is close to 3800 may-be as much as 4,000 lbs. Other things to look at is less rolling resistance, (tire pressure at 36-38 psi?) disc brake , wheel bearing drag and even a higher rear gear ratio. (lower rato number like 2.76 but "around town MPG may suffer while highway MPG improves) Sounds like you have already found some good carb. jetting so that adjustment is not a good place to look for additional MPG. Think about ways to get some weight off the car and how it "pushes the air" at highway speeds. Getting the front end lower to the ground may help but watch those steep driveways. DD

Author:	WhaleMstr [ Thu Dec 13, 2001 1:10 pm ]
Post subject:	Re: Gas Mileage
I recently took my A108 van on an extended doctors visit and got 17.33mpg with it. I am happy with that amount - after the tinkering I have done - it was getting around 13. I don't think that's too bad for a giant brick going down the highway! Later, Dan "I may be slow, but at least I'm not very fast!"

Author:	MitchB [ Thu Dec 13, 2001 1:24 pm ]
Post subject:	Re: 23 MPG is pretty good
I do not know the actual wet weight, but I'd say a fair guesstimate is at least 3700 lbs with me in it. In so far as the axle ratio is concerned, I recently swapped out the OEM 14" tires for 15s. I calculate my effective ratio is now 2.67:1. Low speed acceleration has suffered, but highway cruising is better. Other things I did, but did not mention are: installed a fine wire mesh stainless steel screen under the carb for better atomization/distribution and I fabricated a coolant heated carb spacer. Mitch Quote: : : Not Bad for a heavy car. To be honest, good : racers "work" the same : issues" we just take the improvement(s) : in ETs and MPH instead of MPG. Do you know : what your Aspen weighs "wet"? I am : guessing it is close to 3800 may-be as much : as 4,000 lbs. : : Other things to look at is less rolling : resistance, (tire pressure at 36-38 psi?) : disc brake , wheel bearing drag and even a : higher rear gear ratio. (lower rato number : like 2.76 but "around town MPG may : suffer while highway MPG improves) : : Sounds like you have already found some good : carb. jetting so that adjustment is not a : good place to look for additional MPG. Think : about ways to get some weight off the car : and how it "pushes the air" at : highway speeds. Getting the front end lower : to the ground may help but watch those steep : driveways. : DD mb589@aol.com

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Author:	Bob D [ Thu Dec 13, 2001 6:00 pm ]
Post subject:	Re: 23 MPG is pretty good
Quote: : I do not know the actual wet weight, but I'd : say a fair guesstimate is at least 3700 lbs : with me in it. In so far as the axle ratio : is concerned, I recently swapped out the OEM : 14" tires for 15s. I calculate my : effective ratio is now 2.67:1. Low speed : acceleration has suffered, but highway : cruising is better. Other things I did, but : did not mention are: installed a fine wire : mesh stainless steel screen under the carb : for better atomization/distribution and I : fabricated a coolant heated carb spacer. : : Mitch Did you check the calibration of your speedometer when you went to the 15" wheels? You may want to change your speedometer gear. It sounds like you may be going further than you think on each gallon of gas! Bob D BBobbias@aol.com

Author:	MitchB [ Thu Dec 13, 2001 9:18 pm ]
Post subject:	Re: 23 MPG is pretty good
Yes! I already thought of that. In fact, I guessed I had a 29 tooth speedo gear and purchased a 27 when in fact, I had a 30 and should have installed a 28. So I'm actually turning my speedo slightly faster than I need to and this agrees with my findings. Mitch Quote: : : Did you check the calibration of your : speedometer when you went to the 15" : wheels? You may want to change your : speedometer gear. It sounds like you may be : going further than you think on each gallon : of gas! : Bob D mb589@aol.com

Author:	Dave M [ Fri Dec 14, 2001 7:41 pm ]
Post subject:	Re: Gas Mileage
Quote: : I know most of you here are not concerned with : gas mileage, but maybe you can give me a : fair evaluation anyway. I get a best of : about 23 MPG with my 1980 Aspen. The car has : a 1bbl 225, 904 lockup, 2.94 axle, recurved : ignition and rejetted carb (slightly : richer). Is this about what I should expect? : : Thanks I have a 1976 Duster street car that I drive to work. I put on 100 miles a day of all free way miles. I have a 8 1/4 with 2.45 rear end gears. I found out that their is a big difference how fast I drive. The mileage will change by 4 miles a gallon between driving at 55 MPH or a 75 MPH. damuel@kalama.com

Author:	moparguy [ Sun Jan 06, 2002 10:46 pm ]
Post subject:	Re: Gas Mileage
When i got my Aspen from my grandmother, I drove it home 200 miles or so. I got almost 30 MPG with it. It the super six though. Runs like a top! Its only got 33,000 miles, would that have something to do with it? thanks moparguy moparguy@hotmail.com

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