VCCA Home Forums TECHNICAL - 1945 AND NEWER 1946-1948 1948 mpg.

Took the old girl for a ride today. First outing since Feb. last year. Don't ask. Anyway, left the house with 470 miles showing. Got home with 630 showing. State roads, some small towns with red lights/stop signs. Some road intersections. Open roads ran 55/60 with short burst to 65. 160 miles, took 9 1/2 gallons to top up. Just 16+ miles per gallon. Is that about right for the 216 '48 all stock era car.

A little low but in the ball park. Also the short distance makes an accurate check impossibe. Under normal 1948 conditions they would run from 18 to 20 MPG.
The average milage from Floyd Clymers survey of 1949 owners was 19.71 MPG.

Not sure what I averaged on my trip to Parkway but it done very well. When I first got my car I had regular tags on it and drove it everyday to work and all over the place it was my daily driver for a while...

A 216, with 4:11 rear end will average about 16 or rise to 18 if driven about 50 miles an hour. At least that was what my 52 did prior to the installation of 3:55 gears. No real improvement in mileage but I cruise it at higher speeds.

If 9.5 gal filled it after 160 miles the calculated MPG is 16.8 (almost 17). With 4:11 gears driving 55/60 & occasional burst up to 65 I would not expect better than that. Keep the speed in the 45/50 MPH area and you most likely will get around 18. That has been my experience.

dick

Having had 216 powered cars of various years in my possession for over 50 years, that sounds about right to me. Condition and speed make a lot of difference!

It was the stopping and starting that brought down the numbers

YES, I AGREE. STARTING & STOPPING WOULD ALSO BE A BIG CONTRIBUTING FACTOR ALONG WITH DRIVING 55MPH & OVER.

DICK

I had a 48 for about 10 years. It did about 18mpg in your smaller gallons. I used to come back from long tours and a month later I got a statement from the bank that listed every gas station I called at, and there was always a lot.

If starting decreases your gas milage then stopping will increase it. Your foot is on the accelerator big time on the starting but it's on the brake when stopping. It can't be both ways. Only idling gas is used when stopping. So that distance is like free. See?

You're welcome,
Charlie

Good theory Charlie, unfortunately, it doesn't work that way.

16-18 is where mine likes to be as well. Can't complain I guess. Its better than my '76 and its single digits :)

Charlie Helps the new car company's figure out the gas mileage on the window stickers...Obviously

An engine idling runs very rich and probably would average less than 5 miles to the gallon if one were to calculate it.

You folks who failed simple arithmetic in the third grade won't understand the math involved in the gas milage when one considers stop and go driving. Let me further explain the cyphering.

See there's three phases to the stopping and starting issue. There is the coasting from speed, the stop with no speed, and the starting (accelerating back to speed.

The coasting when coming to a stop is the free milage you can enjoy.

The stop is what is implies. You are not going anywhere but the engine is idling and giving you nothing in return. It is using gas.

The starting/accelerating to speed has you going through the lower gears and on to drive with gas consumption at a premium, i.e., low gas milage.

Stopping increases gas milage.
Being stopped decreases gas milage.
Starting/accelerating increases gas milage well above the average at speed.

That's the way it works. Stopping, stopped and starting are not trade offs.

Sorry for going way over the heads of many of you. Next year as you attend night school 4th grade math, it will become more clear to you. Perhaps.

To close all speculation on gas milage for a 41-52 with a 4:11 differential (rear end to those in the mountains. Not you Chip. ...well, on second thought you too, I guess.) the sustained milage for 55 MPH highway on flat roads is 17MPG. That is depending on whether you drive on good NC roads or those in PA and VA where you are constantly zigzagging to avoid a plethora of pot-holes, state troopers, lawn-mowers and horse-drawn buggies.

Note: Owing to the design engineering of the 42-48 with their lower hoods and the caps on the doors you can add 1/4 MPG. If you run a Fulton you can subtract about 5MPG.

Charlie

I don't understand the insults when someone asks a simple question and others try to answer it.

Charlie --

Just a quick question.

If de-acceleration increases gas mileage, than why oh why did Chevys and Saabs have the free-wheeling device in their transmissions?? That was a gas saver, and if so, why did they use it v/s just letting you de-accelerate??

Just something else for you to think about.

Jim.

31's are the ones to run.

I will answer for Charlie.
The free wheeling alowed the engine to drop down to idle speed and the car to coast for longer distances than when in high gear. IN high gear with foot "off the pedal" and at say 50 MPH the car would slow down to 10 MPH say in two blocks. In freewheeling (equal to trans, in neutral or clutch depressed) would coast down to 10 MPH in four blocks....so you got two blocks of travel for almost free. With free wheeling the car coasted when ever teh gas pdal was released like going down slight or steep inclines. In a long run doubt if it did much to help the mileage but it did cause more wear on the brakes.
It is proper in a standard shift car to NOT depress the clutch pedal until the car is down to about 10 MPH .

Nothing to do with mileage but free wheeling also allowed shifting without depressing the clutch once the car was in motion.

Thanks Gene --

Another nice feature of free-wheeling was in winter driving on slippery roads. Had more control when letting off the throttle and rear wheels didn't slide, just followed along and one could break in down easy. To this day, on slippery roads when coming to a stop at stop sign or light, throw the auto into neutral and break in down easy.

Gas mileage wise, didn't pay too much attention when driving the ol' 32 back in the 50's, but the 100-200,000 miles we put on the Saabs, there was a definite increase in mileage, let alone the ease of shifting without a clutch with the free wheeling. Interesting note, here in Iowa, against the law to dis-engage clutch when either coasting or going down grades or hills. Never understood why Saab got away with their set up.

Jim.

31's are the ones to run.

To All --

Let me say that I am sorry for the stupid use of "break" instead of "brake". That will teach me to use "edit".

Not sure this is true but I heard years ago that the free wheeling was made illegal and most I have come across have been disconnected and locked out of free wheeling. BTW Charlie and anyone else concerned with the mileage on a 48, or any other year for that matter, just get a motorhome and the mileage on your vintage Chevy will look GREAT!

A car with overdive (common US cars with Borg-Warner OD) also free wheel at low speed when O.D. is engaged. Also can be shifted without de-clutching.
Using free wheeling when going down steep hills or for mountain driving is (was) dangerous as there was no engine braking. That why in some states it was illegal to use free-wheeling for mounting driving....and signs were posted to inform drivers as such. It could cause the brakes to break.

Latigo,

Sorry about the insults. I was just trying lighten the mood some. Please disregard my comment about any schooling we may have had or didn't have. That is not relevant to the instant question.

I apologize even though that was far from my intent. Consider me as having been taken to the woodshed. Again. I'm getting so familiar with the place that recognize every stick of wood still left in there. I'm thinking about moving in. It will save me from having to be dragged there. Hard on me brogans. Is too!

Best,

Charlie

I guess that just went right over my head charlie. I haven't been on here long enough to be familiar with other people's style. Just took it the wrong way.