Technical Gas mileage of a chevy 235 stovebolt engine

I am planning a trip of 1349 kilometers and would like to know what to expect for gas consumption and mileage, I have a stock rebuilt carb on it and stock 58 chevy gas tank if that helps.

 

Ryan!...you left the back door open again!

 

Excuse me? Haha

 

Gas mileage of a chevy 235 stovebolt engine
We need to know if that 235 stovebolt with a 58 Chevy gas tank is in a car, truck, boat, bus, or stepvan. Actually a 58 Chevy truck has a different sized gas tank than a 58 Chevy Impala.
Looks like it might be a 58 Chevy so that helps.
Besides I have no idea how far 1349 kilometers is on American roads. If you mash the pedal to the metal it's gonna use more gas than if you drive like a little old lady.
I'd say fill it up and enjoy the trip. When it gets down to 1/4 tank filler up again.
Ryan shut the back door!

 

Ahem, OK, well from what I read the 235 doesn't knock down any better mileage than a small block. Much will depend on other factors of course. Hopefully more than 10mpg and probly not better than 20. Just looking at one, the intake and exhaust porting doesn't look particularly efficient.

 

Oh sorry I should've been more specific it is in a 58 delray and I did the math and that's 839 miles the only thing I am worried about is I am driving through the mountains and I'd rather not run out of gas right in the middle of them

 

Plan on 15 miles per gallon. Thats about all my 55 sedan with a three speed gets. Thrifty they ain't.

 

Jerrycan

 

Better figure on 150 - 200 liters of fuel. Maybe more if conditions are less than ideal.

Well tuned, tires pumped up to 32 PSI, you should get around 20 MPG provided you do not exceed 100 Km hr or 60 miles per hour. Go faster than that and your mileage drops quickly.

A lot depends on road conditions. On flat terrain, if you can cruise at a steady 100 Km hr without stopping or slowing you could get more than 20. In stop and go driving or in hilly terrain you will get less.

If you are used to taking short trips you will find the mileage gets a lot better on a long trip.

Stock gas tank holds 16 gallons or 60.48L. The farthest you could expect to get would be 320 miles and you would be running on fumes, if you even got that far. I would figure on refueling every 200 - 250 miles or 320 - 400 Km or less. Let your gas gauge guide you.

I wish I could give you a better answer but so much depends on the condition of the car, how heavily loaded, what the road conditions are like, even the weather has an effect. But, maybe this will give you some ideas.

 

What trans do you have ? What's the axle ratio ? What al***ude are you going to encounter ? What size are the rear tires ?

 

1959 bel air, 3 speed o.d.. 15 mpg at 70 mph.

 

Powerglide will get worse mileage than a manual trans. Figure 17 or less with PG.

 

3 on the tree manual gear ratio I believe is 3:55 the max at***ude in the rocky mountains of British Colombia on the road is 7500ft and I have 245 70 r15s I believe

 

What octane?

 

Anywhere from 89 to higher

 

I always gas up every couple of hundred miles , because that next little town may not be open.

 

If you are driving in British Columbia you will have no trouble getting gas. With the six cylinder, the lowest octane regular will be perfect. usually 87 octane in Canada. Figure on 15 MPG average and you won't go far wrong.

You must be starting in Saskatchewan, much of the trip will be prairie which is flat or slightly sloped upward. Mileage will be better than in the mountains if you keep your speed down to 55 - 60 mph (90 - 100 Km hr)

Price of gas in BC, around $1.28 per liter.

This site helps you find the lowest prices for gas, and where the gas stations are located.

http://www.gasbuddy.com/GasPrices/BC

 

I drove my '37 Chevy coupe with a 1961 235 engine on a 3600 mile trip. Car has the stock transmission and a 3.73:1 stock rear axle gear. I also have an overdrive unit installed in the torque tube. Around town, without the overdrive engaged, I got an average of 17mpg. On the highway, at 65-70mph w/OD, I got an average of just under 23mpg.

 

Hi. I have a 1957 235 engine in my 46 coupe shown in my avitar. It is bored 0.060 with flat top pistons, a 264 grind cam (3/4 street cam), hardened valve seats, Hei ignition, clifford 2 carb water heated intake with 2 two barrell webber carbs, shorty tube headers & dual exhaust with 2 46 style stock mufflers & running 3 on the tree stock 46 transmission. I changed the ring & pinion to a 355 & run 700R16 Coker Cl***ic radials on the rear & 600R16 on the front.
Driving 65 MPH I get 16 MPG using 87 octane gas. Surely would get better milage if I slowed it down but with the above setup it just hums with no effort at 65 MPH.
Drives like a dream on the road. Cannot locate the Speedo adapter I purchased to correct the speedo/odometer so I just plug in my small GPS for speed & trip miles. My speedometer is 11 MPH slower that actual speed at 65 with my setup.
Just fill your tank & drive it around for at least 1/2 - 3/4 tank of gas & check your milage to be certain what it is with the gas you use & the al***ude you drive & you will know for sure.
This April I took mine on 2 Tours back to back here in Texas & covered just over 1,100 miles total. Going on one this Saturday with the Inliner Intrenational group & it is about 2.5 hours for me to just meet them where it begins. Will be a good day for sure.
Had a date conflict this spring & could not make the Lone Star Roundup but plan to make that a priority next year so I can get a chance to visit with some Hambers.
I did all my racing in my younger years & now in retirement I prefer the tours & cruises and a occasional show. Not just driving is what it is all about for me.

Enjoy your trip. Jimmie

 

to be safe,i would have a small jerry can with a couple of gallons of gas,just in case your guage isnt accurate,those big old chevys were never known to be fuel mizers when they were new.Good Luck.

 

A lot depends on the condition of the 235 and in the alps I wouldn't expect more then 12 miles to the gallon or about 2 KPL even on a fresh stock motor. Then'58 is a lot of car for the little inline to be pushing around and once in the mountains it is going to be worse.

 

I thought one could make a vintage go more then 2 km pr liter [emoji33]

At least with two carbs and better ignition it should be able to de better.

A Bedford 5 tons truck with a 214 (full pressured 216) can go between 4-6 km/l in stock form, unloaded.

To quote Winnie the Pooh:
So it needs a little of something good! [emoji4]

Wasn't it the 235 or maybe 261 that was in the thrift master? 2 km/l don't sound thrift at all.
I'm not badgering any one, but I firmly believe a torquie little six can be improved on! A lot!

Wasn't it one of the first SEMA gimmicks to make a tri five SB Chevy outperform a smog era big block! Get better MPG and be more Eco-friendly.

It's from the Edelbrock, made in USA- book.

I go look it up, but I believe it was two hot rodders and Vic Edelbrock.

Not to put the OP down, but there might be som money in saving gas!

 

The old idea of inline 6s getting good mileage is really more of an idea then anything else. They were not called a thrift master because off good mileage they were called a thrift master because they cost less to buy.

My calcs may have been a little off, basically if you get 16 MPG out of a 235 you are doing good and that is at this al***ude on basically flat roads or rolling hills. 12-14 is common. Maybe on a new engine you can get a little bit more than that.

pretty much anything will out perform a smog era small block. The Smog era was pretty much the dark ages for GM engines in general. I could get all political and conspiracy theory on that erabut then I would sound like a crack pot. LOL

 

If there ever was an engine in a need for a two carb set up its a I6!!

They used to say over here regarding old straight six shooters; two cylinders runs lean, two runs optimal and two runs rich.
A long engine with a long manifold ain't the right way to use one carb!

I know the OP did ask for advice on better fuel economy, but that long a trip in a 2 km/l.

I can hear my own wallet deflate[emoji17]

 

16 MPG = 14.7 liters per 100 Km = 6.8 Km/L

This is probably the closest guess so far. I figured 15 - 20 MPG but no way will you get 20 in the mountains. I would take the over/under on 16.

The Chevrolet six is a reliable work horse. Not much you can do to get better mileage, tune up the motor, pump up the tires, and baby the gas pedal. Buy the cheapest regular and don't worry about it.

I hope you have a nice trip. The Canadian Rockies, Banff, the Trans Canada Highway, have some of the most spectacular scenery in the world.

Make sure your brakes are in good shape, and don't use them too hard on the down hill runs. Let the engine hold the car back, if you get going too fast apply the brakes hard enough to bring your speed down then take your foot off the pedal and let them cool off. DO NOT ride the brake pedal all the way down the mountain, your brakes will be burned out when you get to the bottom. This used to be a common accident when your car was new, and all cars had drum brakes.

If you think the brakes might be getting hot pull over, stop and let them cool down. Light a cigarette, have a drink of water. Hold your hand on the wheel, if they are hot you will know it. If they are no more than warm you are ok.

 

I had several 235's, none ever got 20 mpg (Imperial gallons, too!) Had a '54 Bel Aire with the stock 235 P-glide engine hooked to a '55 3-speed stick w/OD and 4.11 rear gears. It got worse MPG in OD than Direct, until I put short 14" tires on it, then it got about 18 either way. I put a 283 in it without the OD and it got about 23 all day long.

 

I had several 235's, none ever got 20 mpg (Imperial gallons, too!) Had a '54 Bel Aire with the stock 235 P-glide engine hooked to a '55 3-speed stick w/OD and 4.11 rear gears. It got worse MPG in OD than Direct, until I put short 14" tires on it, then it got about 18 either way. I put a 283 in it without the OD and it got about 23 all day long.

 

Rusty makes a good point about how to use the brakes in the mountains. They are good for one, maybe two panic stops and then you have problems.

 

This helps alot thanks! And actually I'm going to campbell river on the island so I'm starting in alberta a little west of edmonton

 

Start checking your mileage now before heading out on the road trip. Then figure it will be a little worse in the mountains. For practice disconnect the fuel gage and learn to drive it without running out of gas. Apples to oranges, but my 223 six in a big Ford boat could get near 20 MPG, with a good tail wind on the highway. Good luck, be safe and let us know how your trip goes. -Dave