The Stovebolt Site Forums The Shop Area General Truck Talk Gas mileage question???

Hello everyone......didn't know where to post this question, so thought this would be the best place due to the traffic. I bought a 1950 1/2 ton back in March and haven't had it on the road yet. It's got an original 216 CID engine with the one barrel carb on it, and a 3 speed on the column. I wondered if anyone could tell me what kind of gas mileage I can expect to get in this truck. I won't be hauling any loads or pulling trailers.

Thanks for the help,

Spot

Expect 15, give or take a few depending on how you drive.

15 would be right but that assumes you're tuned up and your tire pressure is right.

For some reason I thought I saw a couple posts saying that 235's only got 12 or so, without modifying anything. Is there a reason that 216's get better mileage? Or am I just imagining things again?

Well, I have to say I'm majorly disappointed in such low gas mileage with this 216!! I was expecting to hear they got close to 25! I guess it all has to do with the low gear ratio and the fact that top cruising speed is about 45 mph. Oh well, it is what it is, so I'll live with it. With gas at $4.00/gal. I was hoping for much better.

Thanks everyone,
Spot

I have a T-5 overdrive with a 3.90 rearend behind a 216 and it's no where near 25 (around town driving). But atleast my top speed is greatly improved which was my main objective.

I thought I remembered seeing a topic here like this a while back and someone said that you could get about 20 mpg with a 235 four speed in a Chevy 1/2 ton. Must have just been my day dream.

I used to get 15 mpg loaded or empty in my 1948 216 1/2 ton (4.11 rear end).

I used to get 18 mpg on the highway in my 1954 235 1/2 ton (3.90 rear end). This truck now has a 3.55 but I have not measured the mileage.

Ron Steltz(WE b Old) got 23 or so with his 235 engine in his '54 Chevy 1/2 ton, Thrift Master. You weren't day dreaming. But I think he has a T5 tranny and 2.73 gears. He'd still be getting that but now he gets infinity miles to the gallon because he can't drive his truck right now, it is overheating.

I get 20 on the highway with a 261 bored .030, GM 89mm transmission (.73 overdrive), and 3.50 gears in a Ford 9" rear end. 2000 rpm is 63 mph. I am running a split exhaust and single one barrel carb on a stock intake manifold.

Of course gas mileage wasn't a concern when our trucks were new and gas was 21 cents a gallon!
Samantha

I'm getting 10.4 mpg with a 261 in a 9,340lbs firetruck and I'm happy to get that! I wish it was higher but it is what it is.

Thanks for all the comments......I appreciate it.
Samanta makes a good point that back in the day when gas was 19 cents a gallon the mileage didn't really matter too much, even though they were short on money back then too.

I'll tune up my '50 and make sure the tires are inflated properly and hope for 16-16 mpg.

Spot

samantha, to put it context of gas prices go to this site. http://www.fiftiesweb.com/pop/prices-1954.htm

Gas mileage and top speed depend on gearing more than anything else.Most of the ADs were running 4:11 or lower gears,which means poor fuel mileage and a low top speed. To get decent mileage go to a higher geared rearend or an OD trans. If your gonna use your original 3 or 4 speed trans. with a 1 to 1 ratio to the rear,change the rear out to about a 3:08 set of gears. Or put in an OD trans,700R4 automatic or a T5 5 speed trans where your top gear is around .75 to 1 ratio coming out of the trans.

You can help your overall gearing a little bit by installing taller tires. I run 235/85R-16's on my GMC;the diameter is about 31 inches,compared to the 6.00-16 stockers at 29.5-30 inches. Not a huge difference,but if you need to replace tires anyway,you can benefit from a taller tire in road speed/rpms/mileage,also using a more common size can prove to be less expensive and easier to replace if one should be damaged on a weekend in the middle of nowhere. (not that you'd ever venture out "there" on a weekend...)
Speed

Im getting 21 MPG on a imperial gallon running a stock 235 with a T-5 and 3.08 gears. Checked it with my GPS so it should be accurate.

21 MPG sounds pretty good,compared to 15.My 55 with a 350 and 700R4 trans. and 3:90 rear gets 20 MPG all day long.I could probably do better by going to maybe a 3:42 rear, but I like the low end performance with the 3:90 s.

My '54 235 had 3.55 rear end gears, got 18 mpg. put on Fenton headers and a Borg-Warner .70 overdrive and mileage jumped to 24 on highway, but in town (Los Angeles) was always 15 to 16. One experimental run on level ground uing a small 216 Rochester carburetor and holding 55 mph in o.d. got just over 30 mpg. That was great but entirely impractical, in the slow lane the semi's nearly ran over me, it was scary.

21 miles per Imperial gallon equals 17.5 miles per US gallon.

One Imperial gallon is 4.546 litres, or around 1.2 US gallons

Speed 6351's comments about a taller tire come at a good time. I'm researching tires now for the old girl and I've been leaning towards a taller look, not knowing it would also help with the gas mileage. Thanks for the suggestion. Now to decide between radials and bias-ply.

I've also wondered if a different spark plug would help improve mileage. Would a hotter plug give a better burn and thus better gas mileage? I'll contact Champion or AC and ask their tech dept.

Thanks everyone!

Spot

Spot there is bias plys on my 54 1/2 ton. They are not too bad on a smooth highway (rare around here), but are a handfull on a rough or patched road.

Thanks Hydra .5 ton........I've heard that bias ply tires also "track" on a road that has been used a lot and has grooves in the lane. They might look better, but I'm not so sure they are the best tire. I'm leaning towards a set of radials, just haven't decided what size would look best on my '50. Any suggestions from anyone with experience?

Still wondering if changing to a hotter spark plug would help with a better burn and give better gas mileage??

Spot

Heck, no, Spot. Not unless you have the wrong heat range in there for the type of driving you're doing. More high-speed needs a colder range, and if you use a hotter plug under those conditions you risk engine damage.

If you have a 12V system, consider electronic ignition. That would help some, but as Dale said, final drive ratio is the big thing.

What tires do you have on there now? On my 3800 I'm running 235/80R16's with my newly installed 4.10 rear - same old direct-drive transmission - and I am well pleased.

Hey yeah, in 1954 gas was about $.21 a gal. There were also a lot of people working for $.75 an hour. Although gas is very high right now look around and you will find that everything is a lot higher,cars,houses,groceries,all necessities,and also wages.So although $.21 a gal sounds cheap by todays standards,it was quite high back in 1954.I got my drivers license in 1953,and it was just as hard coming up with gas money as it is today.I worked in a greenhouse from 1953 til 1954 making $.75 an hour.In 1954 I enlisted in Uncles Sams Army where my pay was $71. a month.My point is, it was just as hard on people to survive back then as it is now.

Hey Shop Shark.....I just bought my truck in March and it came with P205/75R15 Firestone radials. Yes, they are 15" tires and I've been strongly considering moving to a 16" taller tire. I think it would look better because it would fill up the wheel well more. I'd also like to have a tire that looks more fat than skinny.

Thanks for the spark plug advice. I'm not a mechanic, only mechanically inclined. I would have thought a hotter plug would have been better. Shows what I know.

Spot

No better way to learn than by asking.

The way it works, generally, is like this: an engine which idles down the strip, showing off, doesn't work very hard. Therefore, all other things being equal, it is cooler inside than one which has a full load of firewood, blasting at full throttle up a steep grade. Given that a certain temperature flashes(ignites) your air-fuel mixture, the one which is working harder needs less of a spark - or, to put it another way, a cooler spark - to bring on the flash.

A 205/75 has a pretty low tread height. Take a look at this:
[IMG]http://inlinethumb50.webshots.com/40497/2252603640096215731S200x200Q85.jpg[/IMG]
Granted, my chassis is heavier than yours, but the fender wells are the same, and if you ignore the number of wheel nuts, this gives you an idea how my tires would look under your truck. And, you'll like the speed improvement.

Thanks Hotshoe. Sure like the look of that tire, so I'll download it and keep it on file. Might be a tad too big looking for my little 1/2 ton vs. your 1 ton. Epic sure looks nice in that original condition and paint job. Good job there. Also, thanks for educating me on spark plugs!!

Thanks for the feedback. I'm still learnin' and appreciate everyone's help.

Spot

the look of the tire and wheel combo a lot depends on the not only the height and width but the offset. i went to smaller tire from the 235-70-15 to a 235/75/15 and the fabricator used a spacer out to the edge of the fender. i little to close i might add it rubbed the tire but i was able to pull the fender out and clears nicely now. see my webshots.

Tire size is one of the things I have to consider with my '58. someone put 16" American Racing Chrome-Nuggets on it with 265/75/16 tires. The huge tires make the truck look weird.

I'm still on the fence as to what kind of rims I should get. I'm getting rid of the chrome nuggets either way... I've never liked them on ANY vehicle.

The standard rearend ratio in those 6-cylinder Chevy pickups was a 4.11 and they were not noted for gas mileage. Most of them had trouble getting 15 mpg. My '60 with a 235 would touch on 16. My '65 with a 283 V-8, 4.11 rear, and overdrive that worked when it wanted too, which wasn't often, couldn't get 15 with the O.D. working. Most of the time it got 12-13 mpg. That would be a big OUCH with today's gas prices. Swapped it for a new '69 Ford with a 360 V-8 and about a 3.50 rear that got 15-17 and had a lot more power. I though I came out way ahead on that trade.