Fuel mileage

[Aron Gleason]

What highway speed are people running? When we go to long distance shows, usually 60-65 mph. 354:1 gears and 2:75x15 on 8 inch rims. We stay off the Interstates so we can see more of State towns and countryside.
We DO NOT treat it as a marathon. It is a vacation. Leave at 7:00AM- until maybe 3M, then sight see or just enjoy the scene.

At 45 mph I buzz the motor at around 3200.

 

[Jerry Hall]

Why keep track at all?

To catch tuning problems before there is real trouble.

 

[440 4 speed]

Why keep track at all?

It’s my choice. I have kept a log on almost all of our vehicles since about 1970. Contains repairs, maintenance and fuel fill ups . Has helped with selling some especially ordinary driver cars.

 

[440 4 speed]

At 45 mph I buzz the motor at around 3200.

What are your gears? Tires?

 

[Aron Gleason]

What are your gears? Tires?

4.57 275/60/15 mickey Thompson radial Pros. 28 inches tall

 

[Aron Gleason]

To catch tuning problems before there is real trouble.

I have a afr gauge and a vacuum gauge to monitor for carburetor issues.

 

[Cheapsunglasses]

I love all these posts. Who cares about gas mileage. Gas mileage isn’t important. Smile per gallon! I wonder how many of these people also make excuses to not drive the car because the fuel economy sucks.

Better fuel economy = more fun. More fun = more miles with smiles. If you tune your car for best fuel efficiency, you’re inadvertently tuning it for best efficiency, which has a side effect, better gas mileage. I have a 68 GTX, 440, 440 source heads, lunati 703, edelbrock performer, and avs2. 833 od, 3.55 gears. I keep a vacuum gauge and a afr gauge in the car, I keep around 11-12 afr highway and 13 afr city with 15-20” of vacuum. I can drive around town like a freaking Honda Civic, it’s so city friendly you’d almost forget it’s a hot rod. It’ll run 70-100 on the highway no problem. But drop a gear and open the throttle, or dump the clutch at a light you’re quickly snapped back into reality you’re driving hot rod. I’ve calculated 13-14mpg . Currently I’m seeing just how good I can get for fun, mostly Highway and being nice, roughly 80 miles and only 5 gallons used, 16 mpg! These cars can be fun, and fuel efficient

 

[66 Sat]

Why keep track at all?

I was taught by a friend's father 30 years ago to always keep track of fuel consumption - as an indicator of problems.
On my daily driver I always reset the trip computer at every fill up. If I get seriously less miles out of tank I straight away know there's some issue with engine, brakes, wheel bearings, tires, something to investigate.
I also keep track of fuel economy on my Satellite, especially on longer runs. Very easy to calculate, gives me peace of mind that everything is in tune.
It's nothing to do with driving like Miss Daisy to preserve gas. If I don't hit 5,000 rpms at least once every trip then I'm disappointed.

 

[Aron Gleason]

I love all these posts. Who cares about gas mileage. Gas mileage isn’t important. Smile per gallon! I wonder how many of these people also make excuses to not drive the car because the fuel economy sucks.

Better fuel economy = more fun. More fun = more miles with smiles. If you tune your car for best fuel efficiency, you’re inadvertently tuning it for best efficiency, which has a side effect, better gas mileage. I have a 68 GTX, 440, 440 source heads, lunati 703, edelbrock performer, and avs2. 833 od, 3.55 gears. I keep a vacuum gauge and a afr gauge in the car, I keep around 11-12 afr highway and 13 afr city with 15-20” of vacuum. I can drive around town like a freaking Honda Civic, it’s so city friendly you’d almost forget it’s a hot rod. It’ll run 70-100 on the highway no problem. But drop a gear and open the throttle, or dump the clutch at a light you’re quickly snapped back into reality you’re driving hot rod. I’ve calculated 13-14mpg . Currently I’m seeing just how good I can get for fun, mostly Highway and being nice, roughly 80 miles and only 5 gallons used, 16 mpg! These cars can be fun, and fuel efficient

With gas prices above $4 a gallon fuel efficiency is a good idea if you want to be able to enjoy it.

 

[Skytrooper]

Yes, I check the mpg on all of my cars as an indicator of possible issues. That being said, with the Charger, I am trying to ascertain the tune.
So far I have not had it on the highway so my figure of 10 mpg is just normal road driving. The engine is all stock setup. The only difference is the 245/70-15 tires on all 4 corners.
Yes, the figure does include some “spirited” driving…the miles per smiles factor. So it is an all inclusive mpg. I mean…who can help but romp on it at times…it’s fun!

 

[66fs]

68 Barracuda, 383, 906 heads, 268 comp cam, 72 400 intake and TQ, Factory exhaust manifolds, dual exhaust, 3.23, automatic trans gets 16 mpg cruising at 70 mph uphill or downhill. All highway, stopping only to fill the tank. Around town, can't measure mpg, too many variables.

 

[BSB67]

Of course you can measure it. My blended driving conditions are what matters to me. Rarely every drive just highway or city or county.

 

[Don Frelier]

I can get over 14 mpg with either of my 383's but that's only checked driving to Carlisle.
It's likely worse driving to work or a cruise night.

 

[gtx6970]

What gear?

approx 11.3 -1 comp, 2800 stall conv. 3.54 dana axle

 

[BSB67]

approx 11.3 -1 comp, 2800 stall conv. 3.54 dana axle

That’s impressive mileage.

 

[68BabyBlue]

Tuned correctly, and good fuel, my 440's get between 12 & 14 mpg. 10% ethanol = 10% less mileage, 20% ethanol = 15-20% less mileage. If you are using 93 octane 10% ethanol, 10 mpg is about right.

Never gave the ethanol much thought, but it sure explains the difference between the stock A/C GTX I ran in the 90s, compared to the one I own today. The first car got 12-14 on Amoco 93 in the 90s, the current one has been getting 11 on pump 93 with 10% ethanol. That includes driving with the A/C running, which I'm sure doesn't help fuel mileage.

 

[440 4 speed]

4.57 275/60/15 mickey Thompson radial Pros. 28 inches tall

 

[440 4 speed]

I think I might have mentioned this before.
Is fuel economy that important for a car that you enjoy to drive mainly in nice weather?
If I got 10 miles to gallon driving to the 50th in Detroit going about 4000 miles in a round about way. Yes we spent money.
If I was lucky and got an in closed trailer for 6000.00 and a good truck for 9000.00. Where would I be? No one sees the car until it gets to the show, no interaction with people at all. For 15,000.00 I can go on a lot of adventures driving the car.
Reminds me of a true story.
Neighbours brother in law was an avid golfer. Golfed on men’s night. One night one of the guys couldn’t make it. So they asked a guy who would fill in to join.
One of the regulars had just bought a motor home. The new guy asked what kind of mileage do you get.
The reply, if you can afford a 70,000.00$ motor home, (who cares about mileage?).
When the car is finished it could cost maybe 100.00 Can to fill up if empty with high octane.
Hope I haven’t bored everyone too tears.

 

[Mackman]

Ok, so I am getting 10mpg in my 440 charger with 727 auto and 3.23 rear. I think that might be par for the course.

What is the consensus?

I have the same setup in a 67 Coronet, I get 12.5-13 mpg. Similar in my 69 GTX. Might want to check your tune- A/F ratio.

 

[Skytrooper]

I use GPS for distance tracking, so I have exact data to use with how much gas I pump into the car. I Speedo has the wrong gear so anything it says is going to also be incorrect.

My question about mileage is mostly a curiosity for me.

P.S. I use 90 octane ethanol free gas.