Fuel mileage

[Sam Buchanan]

17 minutes ago, Los_Control said:

Seems nobody with a old mopar has checked their actual mileage.

 

What's the point?  We're gonna drive them regardless.   ?

Edited March 6, 2022 by Sam Buchanan

[harmony]

43 minutes ago, Sam Buchanan said:

 

Ok....I don't believe you mentioned in your first post that the 94 you purchase is non-contaminated.

I might be wrong but I think all 94 octane is ethanol free.   At least any place that I get it, that's what it says on the pump.  91 octane says "may contain traces of ethanol".  I read that as lawyer talk for yes it has ethanol in it. 

[Los_Control]

11 minutes ago, Sam Buchanan said:

 

What's the point?  We're gonna drive them regardless.   ?

I totally understand. I just was pointing out that a guy asked a simple question.

Nobody actually has a answer with actual mpg.

 

Not one person has stepped up and said I get 10 ... or 16 ... or 20 mpg from my flathead 6.

 

Nobody cares ... I am just pointing out that fact ... while it got switched to metric & liters etc ... nobody posted their actual mileage. That was the original question.

 

 

[plymouthcranbrook]

Well the only time I cared enough to check several years ago before the new carb system and the latest tuneup I recorded about 17-18 mpg(US gallon).

[harmony]

I was having trouble with my carb burning way to rich for awhile.  At that point I took mileage readings and I was averaging around 13 mpg.  Driving mostly 30-50 mph, occasionally up to 65.  Plus about 15 minutes of stop and go in town stuff each time I went out.  I've solved that issue I believe and so I never went back to checking my mileage again. So I'm thinking I'm averaging around 16 mpg now days, judging by the extra miles I'm getting per tank of gas, roughly speaking.

[keithb7]

Every time I take my '38 car out, on the way home every time , it's wide open mashed in 3rd for about 3 miles up the hill home. My modern vehicles record very poor average MPG. I really don't want to know what my flathead would net.

 

Unfortunately no, I cannot answer the original question. Sadly we hi-jacked the thread. Yet it was a fun discussion. Sorry. I'm guilty.

Edited March 6, 2022 by keithb7

[joecoozie]

Los_Control

I tried to bring this thread back to the original question on page #1 with this response:

 

"Just trying to keep this thread on-topic.

Your truck and 52 Coronet will likely average around the same MPG - or at least be close enough to not make that much of a difference.

Coronet might be a little better - maybe....."

 

But it seems that once the thread gets hijacked everybody just runs with it.........

 

I know from my experiences in the past that my old Mopars would get around 18-20 MPG on the highway and 10-15 MPG city.

[Sam Buchanan]

2 hours ago, harmony said:

I might be wrong but I think all 94 octane is ethanol free.   At least any place that I get it, that's what it says on the pump.  91 octane says "may contain traces of ethanol".  I read that as lawyer talk for yes it has ethanol in it. 

Count your blessings, down here in the southern USA our non-contaminated gas is 90 or 91. Our premium ethanol is 92.

Edited March 6, 2022 by Sam Buchanan

[SteveR]

8 hours ago, Los_Control said:

Not important, just noticing not one person yet reported there actual gas mileage.

My first car was a 1965 Barracuda with a 225 slant 6 & 3 speed auto, 13" wheels. I use to get 27mpg 

In England I had a Colt with a small diesel engine. The best MPG was 72

[DJK]

On 3/4/2022 at 4:39 PM, OUTFXD said:

The top and sides of your car are smooth,  The underside has a frame,  Suspension, Drivetrain, and exhaust all hanging out in the wind.  This causes the air to tumble creating drag.   Worse,  This happens with a hard surface three or four inches away (The road). This all makes the engine work harder resulting in higher gas use.

 

Preventing as much air as possible from going under the car can show significant mileage gains.  a partial grill block (Think a piece of Chloroplast ziptied behind your grill) a chin spoiler, side skirts, or a smooth pannel attached to the underbelly are great ways to improve mileage. Get creative and you can find ways to Hide these modifications so your car doesnt look stupid.

 

All in all getting economy out of your car is 50% driving style and 50% vehicle efficency. You can make all the changes in the world but they wont matter if you are simply matting the gas pedal.

 

Check Ecomodder.com for driving techniques

Have you seen the bottom of the new generation Nascar?

[lepic56]

Hi,  I have a hard time to figure out the gas mileage on my 51 Dodge with a 251, 3 speeds, and a 3.9 axle,  It does idle more often & longer than my modern car,  mainly for maintenance and at show (peoples want hear how quiet the engine is,, ?).   But the last time I check it was around 15/16mpg(us) combined,,  and the city traffic up-here is light and I drive 45-50 mph on secondary road,  I should be happy with 15mpg, but with 1,000miles a year it is hard to figure it right,, but since I will be going to the 2022 P15 pinic in N.H... a 350 miles ride one way,, sure will be able to figure out the MPG a lot easier,,

Here a thread from 2017 about Fuel economy,, 

 

[Doug&Deb]

I have no objection to my thread getting hijacked. Oftentimes I learn more that way. I wasn’t asking what mileage everyone was getting just thinking aloud about which vehicle would save on gas. I’ve gotten anywhere from 12-19 mpg with the Coronet depending on the circumstances. My truck about the same. 

[kencombs]

 Not driving my 56 1/2T yet.  But based on history (long time ago) when I used to drive similar vehicles, I'm expecting 15-17.  The higher compression, little two barrel carb and good exhaust may get me up to 20 at moderate highway speeds.

 

Maybe.

 

If the build goes well and stays under budget I'll probably add a wide band O2 sensor and air/fuel ratio gauge to the dash.  With a sensor for the front and rear 3 cylinder groups.  Or at least two bungs to move the sensor from front to back.

  That would help tune the carb setup.  Probably better that just reading the plugs and tailpipe color.

 

We're fortunate here as pure gas, E10, E15 and even E85 are readily available.  Most common rating is 87.  89, 92 and 94 are available also.  Or, a short drive to the airport will get me some 100LL.  All are avg of Motor and Research methods. 

That averaging is why so many people complain of our low octane levels compared to the good old days.  Posted octanes now are lower than they were at one time due to the average, not posting the best looking one for advertising.  Of course, newer cars are not a picky since they can dynamically adjust timing to match the fuel. The run fine on 87, just more power on higher octanes, but because of the computer adjustments.

 

[OUTFXD]

3 hours ago, DJK said:

Have you seen the bottom of the new generation Nascar?

Color me interested! No I have not! What did they do?

[busycoupe]

12 hours ago, SteveR said:

My first car was a 1965 Barracuda with a 225 slant 6 & 3 speed auto, 13" wheels. I use to get 27mpg 

In England I had a Colt with a small diesel engine. The best MPG was 72

Imperial gallons?

[Los_Control]

Actually happy to hear some are getting into the 20+  mpg range.

Now it depends on what gearing and if a overdrive is in play.

I would hope for about 16 with a 1/2 ton truck and 4.1 gears ... I still think is better then some modern vehicles.

 

As a kid I had a 1969 mustang with basically a stock 351 with headers/4bbl I could get 22mpg out of it.

I also had a 1971 dodge Ex-police car ... big ol 4 door, it got 25mpg.

But a few years later with all the smog & emissions added mpg went in the ditch.

 

In comparison, I had a 1987 Ford 1 ton work van with a 351/C6/4.1 gears. It got 8mpg empty, loaded, in town, freeway.

Nothing you could do would change it ... I drove it over 10 years.

 

My current 1991 chebby 1/2 ton 350/5spd/3.5 gears gets 16 mpg. Freeway.

Just thinking the old flathead would get better mpg with the same trans & gears as the chebby.

[DJK]

18 hours ago, OUTFXD said:

Color me interested! No I have not! What did they do?

They are covered with a carbon fiber?? panel to reduce drag. 

[Sniper]

1 hour ago, DJK said:

They are covered with a carbon fiber?? panel to reduce drag. 

Just look under most new cars.  Most of them have some sort of, usually plastic, panel at least under the engine compartment, for air flow purposes.  One thing to be aware of, adding something like that to a vehicle that didn't have one >might< affect engine cooling.  Airflow thru the radiator needs to have a way to get out of the engine compartment.

[Adam H P15 D30]

On 3/5/2022 at 5:07 PM, Los_Control said:

I totally understand. I just was pointing out that a guy asked a simple question.

Nobody actually has a answer with actual mpg.

 

Not one person has stepped up and said I get 10 ... or 16 ... or 20 mpg from my flathead 6.

 

Nobody cares ... I am just pointing out that fact ... while it got switched to metric & liters etc ... nobody posted their actual mileage. That was the original question.

 

 

I posted mine in the first few posts Pg 1.  

[Bobb Horn]

On 3/5/2022 at 7:25 PM, Los_Control said:

Not important, just noticing not one person yet reported there actual gas mileage.

 

My 1987 Ford work van I got 8 mpg, I just could not avoid it and drove it for 10 years.

 

When I retired I now have a 1991 chevy with a 5spd manual trans, I get 16 mpg I doubled my mpg.

 

Seems nobody with a old mopar has checked their actual mileage.    

 

.....The last time I checked my mpg in my 38, was on a rod run with our local group.    Filled up with fuel at start, we traveled 100 miles on secondary roads at mostly 50 to 60 mph checking with a gps.   on the way home filled up with fuel with just a little over 3 gal.      so a good 30 miles per gallon.   the 5 speed trans made a very big difference, compared to 15 to 18 mpg around town with a 3 speed trans..  

On 3/5/2022 at 7:25 PM, Los_Control said:

 

 

[FarmerJon]

Just clocked 14.75mpg, driving around town, with a fair bit of idle time, and a carb that needs some love.

Edited March 13, 2022 by FarmerJon

[Booger]

On 3/5/2022 at 7:07 PM, Los_Control said:

I totally understand. I just was pointing out that a guy asked a simple question.

Nobody actually has a answer with actual mpg.

 

Not one person has stepped up and said I get 10 ... or 16 ... or 20 mpg from my flathead 6.

 

Nobody cares ... I am just pointing out that fact ... while it got switched to metric & liters etc ... nobody posted their actual mileage. That was the original question.

 

 

I would say Booger gets 15-16 mpg. 218ci

[James_Douglas]

On 3/4/2022 at 8:54 PM, TodFitch said:

You are putting 94 octane into an old Mopar flathead? If so, that sounds like a waste of money.

For a long time I would have agreed with the above statement. But after my experience in the big Desoto, it is not as iron clad in my mind as it once was. See the old thread....

 

If one is looking for maximum power which can mean an stock to aggressive ignition setting then 94 may be needed. Of course this has to do with the compression and its relationship to the timing. I have replicated the issues talked about in the old thread since 2016 and it holds. I have the ignition such that it does not ping, audibly, with both high and low octane but it has more power with high. I suspect strongly that I have some flame front happening before TDC with low octane that is robbing power but one cannot hear it.

 

James

 

James

 

[wallytoo]

On 3/5/2022 at 7:25 PM, Los_Control said:

Not important, just noticing not one person yet reported there actual gas mileage.

 

My 1987 Ford work van I got 8 mpg, I just could not avoid it and drove it for 10 years.

 

When I retired I now have a 1991 chevy with a 5spd manual trans, I get 16 mpg I doubled my mpg.

 

Seems nobody with a old mopar has checked their actual mileage.

 

 

yeah.  so i have averaged just under 5 mpg since 2007, with just over 11K miles put on.  most of those miles with the original 237, about 2000 miles with the 251.

 

 

 

 

 

 

 

 

 

 

 

 

 

it's also a 13,500 lb gvw dodge dump truck...thank goodness for the 2-speed rear, or it would be worse.

Edited March 13, 2022 by wallytoo