primitives discuss old cars

[franksolich]

http://www.democraticunderground.com/1018763983

Oh my.

raccoon (23,598 posts)    Sun May 24, 2015, 01:14 PM

Why did cars of yesteryear have poor mileage?
 
I know that when gas was cheap, nobody cared about poor gas mileage.

I'm just wondering why the cars had poor mileage, especially with no AC. 

Hoyt (19,698 posts)    Sun May 24, 2015, 01:20 PM

1. Bigger engines, old technology, heavier, stupid drivers (including me), transmission gearing, etc.
 
But, the relatively cheap price, little competition based upon gas mileage, lack of government interest in enforcing higher gas mileage, lack of public interest/recognition, etc., was probably the main culprit. Back then, everyone smoked and ate trans fat too.

Oh, in the 1960s and early 1970s there was a rumor that some guy developed a carburetor that got 200 miles to the gallon, but the auto companies bought the patent and hid it. Didn't believe that one, but the conspiracy theorists did.

Turbineguy (20,176 posts)    Sun May 24, 2015, 01:46 PM

2. Cooler engines, lousy gas miliage.
 
a big loss was cooling. Thermostat setting used to be 150 Deg F, now 210.

Less cooling heatloss, less gas needed, less exhaust, less gas needed. Lower friction, less loss.

It all works together.

The radiator on my newer 250HP car is smaller than my 60HP car of the 1960's.

Also now, better combustion control, VIT VVT it goes on.

Populist_Prole (4,641 posts)    Sun May 24, 2015, 02:09 PM

3. Several factors
 
Less precise control of the fuel/air ratio due to Pre-EFI setups. Carburetors needed to be adjusted and maintained to provide optimal driveability and efficiency. Many were neglected.

Pre-electronic ignition era engines didn't stay in optimal tune very long because there was wear on the various moving parts of a point/condenser ignition.

Other than single purpose high-performance use, many engines were "de-tuned" or under stressed for longevity/reliability, but this decreased efficiency, volumetric and otherwise.

Another important factor was that overdrive transmissions were seldom used except in a few specialty applications....and in trucks, which is outside the purpose of this discussion. This meant that with top "high" gear being 1:1, the only way to control the final drive ratio was through the rear axle/transaxle ratio. It had to be low or "short" ( numerically high ) enough to provide adequate enough initial acceleration, especially on weaker engines with little low-end torque. This made cruising RPMs too high, especially if the rear axle was geared toward high acceleration. If cruising RPM was to be kept low, initial acceleration would be too lethargic. Larger displacement engines were more tolerant of "tall" axle ratios but then you're talking big engine and big car...which works against fuel efficiency.

Concurrent with all these developments, you had much improved quality metallurgy and lubricants, which allowed tighter clearances and for the engine to be stressed and in a higher state of tune and thus more efficient.

Then we throw in wild cards like shapes and length of the intake/exhaust paths and stuff like combustion chamber design.

An interesting evolvement. A 1960's VW bug was, comparatively, a gas sipper in its day, but the engine was detuned and the gearing less than optimal. 25 mpg was a common figure. A fire breathing V8 mustang of today gets better mileage than that even in daily life....provided you're not barking the tires through every gear at WOT. 

Major Nikon (17,857 posts)    Sun May 24, 2015, 03:07 PM

5. The first one is the biggest factor
 
Most piston aircraft have very old engine designs which haven't changed much in the past 60-70 yrs or so. Most of them have manual pilot controlled fuel/air mixture controls. So long as the pilot knows what they are doing, the mixture can be adjusted to rival the efficiency of the most advanced auto engines of today.

aint_no_life_nowhere (21,337 posts)    Sun May 24, 2015, 05:23 PM

7. One of my old cars gets nearly 40 mpg
 
It's a '61 Renault, one of the lightest production cars ever built at about 1200 lbs (about 400 lbs. lighter than a VW bug. All my old cars get good gas mileage even though they have carbureted engines which is less efficient than fuel injection, because they are small and light ('61 Renault, '69 Citroen DS, '73 Saab 96, '57 DKW 3=6). They all have small engines with small displacement with only 4 cylinders except the DKW which is a 3 banger. In my opinion they are much prettier to look at than the horribly ugly and grotesque cars made today and they are more fun to drive. Today's car in my opinion has no spirit, no style and usually is very heavy, like a tank. I will never own a new car. 

Enthusiast (39,330 posts)    Sun May 24, 2015, 06:04 PM

8. Great posts.
 
There are many factors.

One factor is the old style torque converter in automatic transmissions. In modern times torque converters "lock" so the mileage figures are now similar for cars equipped with manual and automatic transmissions. There used to be a significant loss of MPG with automatics due to slip in torque converters.

Additionally all vehicles now have "overdrive" transmissions. It used to be automatic transmissions had only three and sometimes only two forward gears. This forced the engines operate in a less than ideal rpm range. Now automatic transmissions seldom have less than five speeds allowing the engines to operate at a relaxed pace that requires less fuel.

Toward the 2,000s there was a real effort to decrease wind drag on auto bodies. This mostly increased the highway fuel economy.

As several have mentioned, electronic fuel injection has been adopted on virtually every passenger car engine. Not only that but the engines are equipped with sophisticated "engine management systems". The computer uses sensors that determine the optimal air fuel mixture and automatically adjust the fuel injection and ignition accordingly. Due to emission requirements a vehicle must remain "in tune" for 100,000 miles. This means your car is no longer subject to huge variations due to wear on ignition components as in the past.

Remember when you had to replace your "points, plugs and condenser" every 20,000 miles or so? Now your car has 100,000 mile rare earth iridium spark plugs and there are no points or condenser.

All these things work together to increase your MPG. 

olddots (6,466 posts)    Mon May 25, 2015, 04:19 PM

19. scary fact
 
Transmition fluid used to contain whale oil till around 1978 ......

[I_B_Perky]

The old cars had one thing going for them... there was plenty of room to work on the engine and anyone with half a brain could fix most of what went wrong with them.  Now days you got to have a rack, a machine to read the computer and real small hands to work on the darn things.

[obumazombie]

Don't they remember the Yugo ?
50 miles to the gallon
with their knees to their chest
and they think that they're better
Than all of the rest...in a Yugo

[diesel driver]

The old cars had one thing going for them... there was plenty of room to work on the engine and anyone with half a brain could fix most of what went wrong with them.  Now days you got to have a rack, a machine to read the computer and real small hands to work on the darn things.

That's what I like about my '78 Malibu.  V-6, 3-speed auto, carburetor...28mpg.  My son has a 2011 Ford Ranger, 4-cylinder, 5-speed manual tranny, fuel injection, gets 25 mpg.

You also don't need a degree in computer science to work on it.  All I need to fix it is a hammer, pliers, screwdriver, adjustable wrench, duct tape, and baling wire.  If none of those work, it's BROKE!   

[JohnnyReb]

In 1953, my dad took us from S.C. to Dallas Texas to see relatives. We drove a 1951 Cadillac "60". A "60" was a tank of a car, large, next one bigger was a limo. It averaged 22 MPG out there and back on mostly two lane roads.

In 1966, I bought a 1964 Plymouth Belvedere with push button tranny and a 318 engine. I drove it like any wild teenager would drive back then and it averaged 22 MPG.

In 1968, wife bought a new VW bug, it averaged 32 MPG on the hwy.

In 1978, I bought a new Oldsmobile Cutlass with diesel engine, PS, PB, and little else....it averaged 28 MPG on the hwy.

In 1982, I bought a new Oldsmobile "98" with everything you could get on it and it averaged 32 MPG on the hwy.

There have been other cars and pickups here but those were the best for gas mileage I ever had.


.......and as someone else has already stated, I could work on and fix just about anything on those but not true these days.

[I_B_Perky]

That's what I like about my '78 Malibu.  V-6, 3-speed auto, carburetor...28mpg.  My son has a 2011 Ford Ranger, 4-cylinder, 5-speed manual tranny, fuel injection, gets 25 mpg.

You also don't need a degree in computer science to work on it.  All I need to fix it is a hammer, pliers, screwdriver, adjustable wrench, duct tape, and baling wire.  If none of those work, it's BROKE!   

In 1953, my dad took us from S.C. to Dallas Texas to see relatives. We drove a 1951 Cadillac "60". A "60" was a tank of a car, large, next one bigger was a limo. It averaged 22 MPG out there and back on mostly two lane roads.

In 1966, I bought a 1964 Plymouth Belvedere with push button tranny and a 318 engine. I drove it like any wild teenager would drive back then and it averaged 22 MPG.

In 1968, wife bought a new VW bug, it averaged 32 MPG on the hwy.

In 1978, I bought a new Oldsmobile Cutlass with diesel engine, PS, PB, and little else....it averaged 28 MPG on the hwy.

In 1982, I bought a new Oldsmobile "98" with everything you could get on it and it averaged 32 MPG on the hwy.

There have been other cars and pickups here but those were the best for gas mileage I ever had.


.......and as someone else has already stated, I could work on and fix just about anything on those but not true these days.

Yep to both. Back then if you carried a few tools and it broke down, chances are you could fix it on the side of the highway. Nowdays, a car quits, you on the side of the road calling a tow truck.

[thundley4]

Yep to both. Back then if you carried a few tools and it broke down, chances are you could fix it on the side of the highway. Nowdays, a car quits, you on the side of the road calling a tow truck.

Not to mention, that parts were a hell of a lot cheaper back then.  Also fewer models meant more parts were interchangeable .

[I_B_Perky]

Not to mention, that parts were a hell of a lot cheaper back then. 

Ain't that the damned truth!!!