Original Fuel Mileage?

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doc540

doc540

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What fuel mileage did a STOCK 1961, 225 Slant Six, A904 A body get with a 3:23 axle ratio?
 
Thanks, but does anyone know for sure, like from a link to early, published test data?
 
doc540 said:
What fuel mileage did a STOCK 1961, 225 Slant Six, A904 A body get with a 3:23 axle ratio?
Click to expand...

MOTOR TREND May 1961.

Valiant 170 c.i with auto and 3.23:

18 - 22 mpg

MOTOR TREND July 1961

no real road test, but compacts comparison:

Lancer 225 c.i. with auto (no rear axle info..):

17 - 21 mpg
 
chryslerfat said:
I am not sure if they even put it in print back then as fuel usage did not matter.
Click to expand...
What?!?! Hmmmm, I wonder exactly what the entire A-body line-up
was designed to do.........., also, ever hear of the Mobile Gas econ-
omy run? It mattered, and the winners bragged about it then as now
& thank you Marvin, I love it when folks can pull that stuff out.
P.S. I would venture the 225 had 2.94's std., but anything in the option list...
 
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I'll Have to check but I think ether the owners manual or add material puts it at 3.55 std. on the lancer 770 2d with 225 and auto . I know it's a lot tighter than my 69 dart with 2.73 or there about The little Lancer can do a nice job at putting you back in the seat. but the dart gets 28-29 mpg so it's a trade off.
 
They didn't do "as well as" you'd think because nowadays everything has overdrive and people automatically compare, which is an unfair comparison.

Most anything with 3.23s and a short tire like those cars came with will be spinning over 2500 RPM at highway speed. The goal for modern vehicles with overdrive transmissions is "somewhere" around or below 2K RPM at highway speed. That seems to be the magic range. And if you experiment with it yourself, you can prove it. I keep the engine in my truck at or around 2K most of the time and it gets right around 20 give or take.

Slant Sixes "never really" got " that good" anyway. Lots of people on here claim way more than any of them ever really got. Either trying to brag, measuring fuel mileage wrong (which is probably the biggest mistake) or just out and out lying about it.

It's a pretty well known fact, the 318s routinely bested the slants mileage wise and it's not difficult to see why. It takes more of a smaller engine's power to pull the same weight.

Now, that said, there were some exceptions such as the Dart Lite and Feather Duster. Those cars could get close to and possibly a tad over 30 MPG, especially those equipped with the 4 speed overdrive. Anybody who says they ever got that without overdrive is just wrong. They were not that economical.
 
Too true,my 318 4spd '69 custom w/3.23's and short tires avg'd 18
mpg combined w/o any romping crane blazerII cam & 600 holley. My
2bbl. cammed /6 w/more comp. 3.55's and & taller tired '72 swinger
w/ a/c avg'd........18 mpg combined...w/ a wee bit of romping.
 
Killer6 said:
What?!?! Hmmmm, I wonder exactly what the entire A-body line-up
was designed to do.........., also, ever hear of the Mobile Gas econ-
omy run? It mattered, and the winners bragged about it then as now
& thank you Marvin, I love it when folks can pull that stuff out.
P.S. I would venture the 225 had 2.94's std., but anything in the option list...
Click to expand...

I have also the results of the 1960 Mobilgas Economy run (published in MT April 1961).

But these are no 'every day' mileages, these are mileages under very special conditions.

Two Valiants attended this contest in the class A (compacts).
One achieved 27,3 mpg the other one - should have been a 225 c.i. - 26,5 mpg.
No details in this article about the cars, but I think, they would not have chosen automatic transmissions...
 
- Marvin - said:
MOTOR TREND May 1961.

Valiant 170 c.i with auto and 3.23:

18 - 22 mpg

MOTOR TREND July 1961

no real road test, but compacts comparison:

Lancer 225 c.i. with auto (no rear axle info..):

17 - 21 mpg
Click to expand...

Thanks, that's what I was looking for.

Looks like I have some tuning yet to do on my 225, .030 over, with Clifford cam, intake, Holley 390, and shorty headers. It's an A904 with a 3:23.

65mph highway cruising is only getting 15.5, and that's without mashing the gas to pass.
 
I understand they did better than equivalent Ford & Chevy of the day. They were also much faster, taking all the medals in six cylinder competitions, so much so that GM & Ford got those classes eliminated. The T-bar suspension helped a lot on twisty tracks.
 
doc540 said:
Thanks, that's what I was looking for.

Looks like I have some tuning yet to do on my 225, .030 over, with Clifford cam, intake, Holley 390, and shorty headers. It's an A904 with a 3:23.

65mph highway cruising is only getting 15.5, and that's without mashing the gas to pass.
Click to expand...

If you want to tune for mileage, you can do a LOT better than a crappy Holley. One of the smaller Edelbrock carburetors would get even better mileage. They have very small primaries.
 
To improve mileage, step 1 is HEI ignition, since easy and cheap.
If buying new tires (or wheels) anyway, go larger OD for smoother highway running w/ better mileage. Thinner tires are also more efficient.
Multi-port fuel injection should help a lot in the slant engine, since the middle cylinders tend to run rich and outers lean w/ a carburetor, and probably also would w/ TBI. Whatever you do, don't over-carb any engine or the fuel will not atomize well.
I religiously recorded mpg in my 1969 Dart 225 in the 1970-80's of higher gas prices. I always got 22 mpg highway (55-60 mph then, remember the limit).

If you want good mpg, don't drive 70 mph. On long trips, I see up to 33 mpg (instant monitor) in my 2002 T&C van when I follow a semi at 60-65 mph, vs 23 mpg normally. Unlike MythBuster's results, I follow at a safe distance, indeed other cars cut between me and the truck. Doesn't work well if a cross-wind. There are many other hyper-mile'ing ideas. Every time you brake, you waste energy. If you pedal a bike much, you have a better feel for these.
 
Thanks, I have HEI ignition.

But I'm not buying another new set of tires and wheels since mine have less than 1K miles on them.

And the 390 Holley is working just fine. I'll live with my current mileage lay out the cash for a new carb.
 
Another thing to consider, is the quality of the gasoline back then......that alone would likely increase mileage a little bit on its own. You WONT get the same results with the ethenol blended gas of today.
 
At 15.5 all around mileage is about as good as your going to get without spending more $$. I don't agree with some on here that some slant 6 powered vehicles can't get thirty mpg on the hwy if the right combination of parts are used and your willing to limit your cruising speed (and RPM). My '61, on hwy, gets right at 30, but has unmodified engine, a weber 2 bbl (with thriftier fuel metering compared to Holley's), 2:94 rear and oversize 14 tires, and my hwy speed is limited to 70 mph. At 80 mph (typical hwy cruising speed on I10) mileage drops significantly to 24.5 and to 15 at 90 mph. For economy, the factory engine specs work best. As a corollary, the last hot rod /6 I had only delivered 10 mpg in the best of conditions. Like many others here, I wouldn't worry about the mileage as much as keeping it properly tuned and maintained for longevity.
 
Thanks, I'm not concerned about the mileage, just curious how it stacks up against an original '61 225
 
- Marvin - said:
I have also the results of the 1960 Mobilgas Economy run (published in MT April 1961).

But these are no 'every day' mileages, these are mileages under very special conditions.

Two Valiants attended this contest in the class A (compacts).
One achieved 27,3 mpg the other one - should have been a 225 c.i. - 26,5 mpg.
No details in this article about the cars, but I think, they would not have chosen automatic transmissions...
Click to expand...
Of course, the response was to the idea nobody cared "back then", which just isn't the case....the corvair,falcon & valiant/lancer were all compacts designed for economy and efficiency.
 
Yes, people did care back then. Remember, back in the early 60's, a lot of people like my Dad went through the depression. They were probably more $$ conscious than we are today. I pumped gas in the 60's, and many people tracked their mileage. My sister had a '66 Dodge 2 door post car. 225 auto. 55 on the interstate would see 22-23 mpg. My '72 Duster 318 auto got about the same.
 
Own 3 early a bodies and only one that is stock is 65 valiant with 273 commando, auto trans & 3.23 rear. Have owned for 10 yrs. and she consistently gets about 18 mpg combined city/hwy which is pretty damn good IMHO.
 
For sure buyers cared about mileage. That is what stimulated the A-bodies. The sportier pony-car styling came later, following the success of the 64 1/2 Mustang. I dare say that fuel prices were higher in the early 1960's, and people were buying small Euro cars like the VW Bug. I recall one business put a "gas wars" sign on the highway every time prices were dropping. Our family took the train for 200 mile trips, because cheaper, roads were less developed and more dangerous then, and cars were still thought unreliable. Even more so when I began driving in the mid 1970's. Prices more than doubled over a few months during the 73 Mideast war, so stations switched to posting price in $/liter, claiming it was a long-planned move to the metric system. Indeed, in the late 1970's, people were thinking that petroleum was on a long declining slide. Little did we know that would reverse, once people switched to 4 cyl cars and oil exploration increased. That is a big reason people still think fondly of President Reagan after the Carter years. President Carter was well-meaning but perhaps overly pessimistic. The recent oil glut, due to fracking and the Alberta oil sands was would not have been believed during the dark 1970's.
 
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