Gas Mileage on Stock 383-4 68 Charger

[triple_green]

I drove to Seaside, OR for a car show this weekend (400 miles round trip). The car performed flawlessly..the only thing is it only got about 13.5 mpg on the trip. I did stop a couple of times. I thought I remembered getting 17-18 mpg onm the highway before. I haven't done a tune up for a couple of years (4K miles) but it seems to run fine.

What kind of mileage are you guys getting with a similar car/engine?

383-4 stock AVS carb 5 yo rebuild. 3.23 rear end. 28" tires (275x60x15); 727 automatic. petronix ignition kit other wise stock.

I can't see any vacuum hoses disconnected or anythink like that.

Thanks!

[Baldwinvette77]

Checked your tire pressure? More people than you think run about 10 psi lower than they should 

[Homerr]

The 69 Charger I had with 383-4, stock AVS tuned by a shop, 3.23 rear, 727, 14" wheels with 235/70 tires, unknown cam "similar to a purple shaft", stock intake/exhaust manifolds did a 200 mile freeway/expressway best of 13mpg.

[myk]

Not too many "stock" muscle cars around, anymore.  A "stockish" Charger like mine will get from 11-13mpg freeway...

[TUFCAT]

I think its hard to calculate MPG on these old cars using traditional methods anymore.  With the fuel senders the way there are, nobody really knows for sure when they are empty ("E" is unknown territory).  Some cars can go from 1/4 tank to "E" almost instantly and then stay there for 100 miles,  if the sender is giving incorrect readings.  Its easy to short fill the tank creating lower than actual mpg calculations.  

[Cooter]

Got about 14 going to Carlisle bout three years ago with 440 and 5 speed.

[c00nhunterjoe]

18 sounds pretty hard pressed, even with 3.23's and a tall tire. 13-14 sounds about right.

[TUFCAT]

18 sounds pretty hard pressed, even with 3.23's and a tall tire. 13-14 sounds about right.

I'm thinking at least 16-17 mpg can be achieved on the highway without a foot in the kitchen. 

[XH29N0G]

I only remember 16 or more when I had an OD on a stock or near stock set up (3.23 and 383 4 bbl).  I think I may have approached 20 mpg once.  Otherwise, it was worse.

[Dans 68]

18 sounds pretty hard pressed, even with 3.23's and a tall tire. 13-14 sounds about right.

I agree.

Dan

[c00nhunterjoe]

18 sounds pretty hard pressed, even with 3.23's and a tall tire. 13-14 sounds about right.

I'm thinking at least 16-17 mpg can be achieved on the highway without a foot in the kitchen. 

Only way i can see it is 1200 rpm cruise on perfectly level roads for the whole trip with no traffic on a bone stock motor that is in perfect tune with a tail wind and thats a stretch

[1974dodgecharger]

I got 10 going to Vegas from Phoenix, 383, modified from stock,4 speed,  28inch tall rear, 3.23, 10k miles on rebuild, new fuel sending unit, guage, etc so pretty darn accurate I know when im gonna hit empty as in bone stock empty.


Did it pretty consistently at 10 cruising 80mph, but one time on a long stretch a lot othe other mopar guys were going 100mph in their cars so I hit 100 myself for 20miles on a 50 miles stretch and got 7.

[Ghoste]

I don't really bother to check in any of my vehicles but especially the Charger.  When the tank is empty I fill it or walk.

[cudaken]

When I got my 68 Road Runner from Mom and Day on the highway 15 MPG and around town 12 to 13 MPG. 3:23 gears and 727.

Cuda Ken

[Troy]

My previous 68 Charger R/T with (I assume) stock motor, automatic, and 3.23 gears would get around 14-15. My 70 Challenger with 440 Six Pack, 4-speed, and 3.23 gears has gotten nearly 16 if I can keep the outboards from opening (right around 71 mph). I drive a lot on the highway. Both those cars lose significant mileage in town - probably due to the fun factor of mashing the gas from a stoplight. I haven't had a 383 car running long enough to get good mileage numbers.

Troy

[Paul G]

My 360, 3:91 gears, 28" tire only gets 8 to 10 around town. In overdrive on the highway cruising at 70 or so it gets 12. 

Back in the day the 69 sat, 318 2bbl, no idea what gear, only got 10 in town, 12 to 14 on the highway.

[68charger440]

18 sounds pretty hard pressed, even with 3.23's and a tall tire. 13-14 sounds about right.

I got 19 going cross country with a 383, but it had 2:76 gears and a carter 2bbl. That was about 20 years ago before the ethanol blended gas.

[Ghoste]

Which is another BIG factor, the fuel they serve up now is only good for farm subsidies and government press releases.  Ethanol, sheesh. 

[Troy]

Why do you guys get such crappy mileage? My 76 W250 Power Wagon 4x4 440 auto with 33" tires got 6 mpg and it was a heavy bastard with the aerodynamics of a barn. Couldn't drive it much over 65 mph. My 84 Suburban 2WD 454 auto got almost 11 "empty" and just over 10 towing my car hauler with a car on it. Called it the Great White Whale and was actually fairly surprised it did that well. Unless I'm doing burnouts every block I expect my muscle cars to get well over 10 mpg. None of mine have huge cams nor are they built for the track so maybe that's the key. My Barracuda with the 318 and 2.76 rear gears would get almost 20 on road trips...

(I calculate mileage by always topping off the tank in exactly the same way and then averaging the miles over several tanks.)

Troy

[moparchris]

On my trip from Phoenix to Colorado Springs I averaged 13.5 MPG.  1969 Charger 500, 426 hemi, 4 speed, 3:54 Dana, 225-70-15 radials.  Two 200 lbs+ people and a trunk full of spare parts.  Lots of altitude changes.   65-70 mph.
Chris

[c00nhunterjoe]

My "mild" 383 4 speed with 4.30's and a 28" tire averages 8-11 mpg so far this year depending on who im cruising with. Most of the time im at 2800-3500 rpm in 4th.

[Paul G]

My 73 Charger with a 440, 3:55 gears only got me 7 to 8 MPG around town. 11 is the best I ever got on a road trip. That engine was rebuilt mostly stock, except for an Eddy RPM intake and Holley 750, and Engle K56 cam. And that is where the crappy MPG came from IMO. It ran great. But I would think that the stock intake, cam, and thermoquad would have netted better MPG at the expense of HP.

Who's car is still at the stock build today? Stock carb, stock tune, stock dizzy set up, etc. IMO a car like that should get better MPG than what I currently drive, or most of the rest of us drive today. Back in the day when these cars were new, or used and ready for mods, as soon as we started to swap out stock parts for "go fast" parts MPG hit the floor.

My little 360 makes about 300hp/400ft#. Those numbers were not easily achievable back in the day and still be streetable. So I am not to upset about the crappy MPG it gets, even with overdrive. Actually back then 10 to 12 MPG wasnt crappy.     

[HeavyFuel]

I was chatting with a guy at a car show a couple weeks ago.  He asked me what's the gas mileage, and the reply was that I've never checked. 

He said that his Charger, back in the day, did really well...like in the 20's.  I don't remember what size he said the motor was....but he was a decent guy, and kept going on and on about he got surprisingly good mileage.


One of these weeks I'll have to keep track of mine..

[PlainfieldCharger]

3 trips of 150 plus miles of mostly highway with 355 gearing I average between 10-12. Car has mild cam, eddy heads, thunder series carb. The MPG numbers are close as I take tracked the miles after a fill up drive car for as close to 100 miles and then fill it. I wanted to get a base line for the future.... It seems this is really close to what everyone is getting!!