Your mpg? And mine

[doninpagosa]

I had a 71 Plymouth Sattellite Sebring Plus that I drove from 72 to 76 and it had the high speed rear end and a 318 2 barrell with an auto tranny. On the highway I could average 25 mpg driving the speed limit of 65 mph. When the speed limit was lowerwd to 55, I averaged 26 on the highway. So I think your mileage is realistic sounding.

 

[arsinist01]

Thanks! Glad to see someone believes me lol.

 

[Dako]

Throw several back-to-back highway trips of 100 miles or more at any vehicle and you will see the mileage increase noticably.

As a young(er) man my `72 Dodge long bed p/u used to easily reach into the 16 mpgs with frequent summer trips (bad fishing habit)...and that was running 60-65. Slowing it down to 55 got me into the 17s. That was running a 360, intake and carb (750 Carter thermoquad) off a 340, dual exhaust, A/T, and 3.23 gearing. That same pickup would easily go to 11 or 12mpg in town with a heavier foot.

I agree, traffic flow (ability to maintain a constant speed) has a lot to do with it.

 

[YY1]

I filled up the tank in the 73 satellite I just got the other day.

I've put about 35 miles of mixed driving on it and the needle hasn't moved off the "F" mark yet

BTW it already had right at 1/2 tank....and it still took $38 at $3.15/gal!!

 

[mopar367]

My 2002 ram 1500 4.7 gets best of 15-17 mpg, 13 in the winter.
My 1987 ram with a 360 auto 3.23 gear gets about 13mpg or less depending how I drive.
Either way Its almost 20 bucks every time I take either one out

 

[charger360]

my buddy waygun has a 73 satty wagon with a 3 on the tree and a 318 and he gets great mpg. as well i am going to let him know about this thread as i am sure he will chime in.

 

[1badstroker]

Well, I get 3 MPG in town stoplight to stoplight and if I can get into high gear and stay there at about 50 MPH at about 2500 RPM I can double my milage and get 6 MPG. That is with a 500 plus in. wedge, 590 plus lift cam with a 312 duration, 5500 stall, 456 gear with a 28.5 in tall tire. That keeps the miles down on the car.

 

[rog_allen]

well, i get 3 mpg in town stoplight to stoplight and if i can get into high gear and stay there at about 50 mph at about 2500 rpm i can double my milage and get 6 mpg. That is with a 500 plus in. Wedge, 590 plus lift cam with a 312 duration, 5500 stall, 456 gear with a 28.5 in tall tire. That keeps the miles down on the car.

nice !!! Sux gas & hauls azz !!

 

[rolling_Thunder]

my 68 Charger got about 18ish mpg when it had the stock 318 / 904 with 2.76 gears... that was an average of street and highway driving. Not sure of mileage with the 6.1L hemi and the 6-speed yet.

Best mileage I ever got was 27mpg in my former boss's 1970 Superbird. 440+6 / 4-speed with a 3.54 Dana. The only reason I got 27mpg was I had swapped in a OD 4-speed which kept the rpms low enough to run off the center 2bbl carb. Other than that - it is a stock car.

I have also gotten 22mpg in a 1968 GTX convertible with a stock 440 with an OD 4-speed and 3.54 Dana

 

[YY1]

OK, so I checked my MPH against a GPS.
It was off by 3-4 MPH at 50. (had factory 14", now has 15s)
Car showed just under 50 but was really 45.
Car showed just under 55 but was really 50.

How do I factor that into the MPG?
ODO shows 176.2 miles traveled.

Since I took the measurement at 50, can I add 3-4 miles traveled for every 50 shown by the odometer?

 

[arsinist01]

Do the math and figure out what it is off by as a percentage. Then factor that percentage into your distance traveled.

 

[Dako]

It's easy...if you are off by 4 mph at 50 mph, then every 50 miles you tavel on your odometer you are actually traveling 54...0r every 100 miles you actually travel 108 miles. Just add the difference to your total miles traveled before dividing by the number of gallons gas you put in the tank...Don't foget the tenths of gallons! You want to be accurate, right?

For all following along who own a newer car that 'tells' you your mileage or have not tried to calculate gas mileage without a trip meter, Herer's the way we did it when I was a young(er) man:

--Write down your mileage when you fill your tank.
--Drive your car as usual.
--On your next fill up,write down the new mileage and the gallons (including tenths) you put in the car.
--Subtract your previous mileage from your mileage showing when you re-filled the tank. This is the same as what is displayed on trip meters in newer cars.
--Divide that number by the amount of gas (gallons) you put in the car, and that tells you how many mpg you actually got.

I have went further with my daily driver (`95 Dakota) and checked the average of three tanks each, reg, mid-grade, and premium. Mileage did go up a bit by respective fuels. For me, the mid-grade was the most cost effective gas.

 

[YY1]

So I came up with about 12...but...

That ws probably the most this car has been driven in a few years, and...
It included lots of idling time, and some "high idle" due to-
Adding refregerant to a/c, and the choke idle and normal idle were set WAY HIGH when I got it.
Also some "spirited" starts, just to see what it has, and LOTS of short trips around the block for testing and tuning.
It does pretty dang good.
We'll see what I get next time.

 

[Donniejr81]

I'm kind of wondering how my 71 Charger is going to do when I get it back together. It'll have a rebuilt 400 with very conservative cam (either the Eddy Performer or factory 383HP cam) 600 Carter AFB and 2.76 rear. Im guessing in the neighborhood of 10-12 city/ 14-16 highway...only time will tell.

 

[Dako]

"...Car showed just under 50 but was really 45."
"...Car showed just under 55 but was really 50."

"It was off by 3-4 MPH at 50. (had factory 14", now has 15s)"

Unless you mounted much lower profile tires, going from 14s to 15s, you should be seeing a lower mph on the speedo than what you are actually traveling, not higher.

I believe most of these cars originally came with 185/ 75 x 14...that's about a 25" dia. tire. Something like a P255/60 x x15 is a 27" dia. tire.

 

[YY1]

I'm just going by what the speedo and the GPS said.

I had noticed I was getting passed by all the Yarris', and thought it was just because I was babying it.

Measured tires- got 26".

Oh, and some of my measured driving was with the a/c on

 

[Sixpack70]

My 69 Mustang with a 351w and 4spd got 20mpg all highway with 3.25 gears. My 05 Hemi Jeep would get 22 all highway with MDS but made a solid 130hp more than my 351w. My friends 64.5 Mustang would get 26 with a 200 inline 6. 26 from a 318 sounds a little high unless you had a 2.xx gear and overdrive.

 

[pabster]

People have often asked me what mileage I get in the Green Monster. Yeah, it's a completely stock 318 2bbl, but I'm pretty sure I've never gotten over about 20mpg. Never really calculated it, since I'm too busy revving the engine next to Priuses at stoplights!

 

[waygun]

Based on when I run out of gas...(fuel guage does not work) I am getting 24 MPG on the highway driving the speedlimit.
That's with a 3 speed manual transmission and 3.23 open gears in a 73 Satellite wagon.
BTW I am running 2356016 Goodyear Assurance Comfortreads which are the same OD as the original bias-ply tires.
With no power steering,only the fan and alternator run on the same belt.
I did install a 5 blade clutch fan,dual exhaust,and thanks to Charger 360,a rebuilt 2bbl Carter and recurved dizzy.
Driving 5 MPH faster drops it to 21 MPG
City driving guestimate is 16 MPG--but hard to calculate with all the stop and go,idling,etc.
With a 21 gallon tank I managed to drive from New Jersey to home on the same tank.
That's impressive for a 39 year old car with 71,000 miles on it.

 

[nelsontoddpa]

My 67 convertible with original 318 2bbl was getting 18 on the highway