The Stovebolt.com Forums Home | Tech Tips | Gallery | FAQ | Events | Features | Search
Help is a click away!

VEHICLE
INFORMATION
KITS


at the

GM Heritage Center
All the details are here.

Searching the Site - a click away
click here to search
New here ??? Where to start?
Click on image for the lowdown. Where do I go around here?
====
Who's Online Now
3 members (Otto Skorzeny, Pre '68 Dave, BCBill), 289 guests, and 1 robot.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums66
Topics128,101
Posts1,056,178
Members48,436
Most Online14,466
Apr 26th, 2026
Step-by-step instructions for pictures in the forums
Brad Allen's photos

AD Chevy Trucks

Pictures galore
Over 6,000 pictures

Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips.

Check them out!

Lots of work on Brad's part ... pure enjoyment (and references) for you!

Big Thanks!

THANKS!

For helping keep this great
old truck web site
on the Internet for

over 30 years!

and not clogged down
with Ads!


Again, thanks!

Previous Thread
Next Thread
Print Thread
#49842 09/01/2005 11:01 PM
Joined: Oct 2004
Posts: 27
B
Junior Member
Junior Member
B Offline
Joined: Oct 2004
Posts: 27
Could any body give me the average gas mileage on a straight 6 235.


If ain't broke Break it and fix it.
Joined: Apr 2004
Posts: 703
J
Jed Offline
Shop Shark
Shop Shark
J Offline
Joined: Apr 2004
Posts: 703
There would be alot of things that would factor into the answer, i.e. gear ratios, driving habits etc. However, I would guesstimate low to mid teens, at best, and on average.

Joined: Feb 2001
Posts: 4,095
W
'Bolter
'Bolter
W Offline
Joined: Feb 2001
Posts: 4,095
i can give a below average on mine with dual carbs, dual exhaust, 2.73 rear end and a 5 speed. in town 9.5 on road 12.5. ron


Ron, The Computer Greek
I love therefore I am.
1954 3100 Chevy truck
In the Gallery
2017 Buick Encore
See more pix
1960 MGA Roadster Sold 7/18/2017
Joined: May 2001
Posts: 1,904
W
'Bolter
'Bolter
W Offline
Joined: May 2001
Posts: 1,904
I got 11.7 MPG with the old 235 and the rather short, original 4.57 rear end of my 3/4T.

I haven't measured it with the 261 and 4.10 rear end.


1948 3/4-Ton 5-Window Flatbed Chevrolet

34 Years. Now with a '61 261, 848 head, Rochester Monojet carb, SM420 4-speed, 4.10 rear, dual reservoir MC, Bendix up front, 235/85R16 tires, 12-volt w/alternator, electric wipers and a modern radio in the glove box.
Joined: Oct 2002
Posts: 4,066
Bolter
Bolter
Joined: Oct 2002
Posts: 4,066
mine gets 15 to 20


Redryder pix
My Hotrod
A veteran - whether active duty, retired, national guard, or reserve - is someone who, at one point in his or her life, wrote a blank check made payable to The 'United States of America', for an amount of "up to and including my life."
I am fighting cancer and I am winning the fight | Pain is part of life; misery is an option.

Joined: Oct 2003
Posts: 66
T
Wrench Fetcher
Wrench Fetcher
T Offline
Joined: Oct 2003
Posts: 66
Mine is a '50 3100. I have a 1956 235, coupled to a Muncie three speed. I have a 12 bolt GM Corporate rear end. I use Mobil 1 Extended Performance oil. I have Fenton headers, a Patrick's stainless steel dual exhaust, a Carter YF, MSD ignition, Magnicor cables, and a big size 15 1/2 right foot. The left foot is 15 1/2 too, but it has no impact on fuel economy!

I get a 14 MPG on the highway.

With the price of gas as it is I need to get going on that overdrive transmission!

Joined: Mar 2004
Posts: 3,068
'Bolter
'Bolter
Joined: Mar 2004
Posts: 3,068
I get about 4 or 5 MPG. Of coarse mine is in a 1 1/2 ton and I'm usually hauling 6 to 8 ton of gravel or dirt,
Scott


Scott Ward

2 1948 1.5-ton Loadmasters
The red one and The snow pusher
1 1950 3100
1 1955.1 Chevy 6500
1 1954 Chevy 6500 2-Ton
1 1955 1st Series COE 5700
1 1963 K20 (454)
1 1964 C10 (350)
1 1951 1.5-ton Dump Truck
1953 and a 1956 Ford F800

Raising a teenager is like trying to nail Jello to a tree!
Joined: May 2004
Posts: 920
B
'Bolter
'Bolter
B Offline
Joined: May 2004
Posts: 920
I can get 12 to 20, depending on my mood and/or load. Wind direction can be a major factor. 62 C-10 4spd 3.90 posi Longbed Fleetside.


1962 Fleetside 4spd 235 w/O.D. posi 3:90
In the Stovebolt Gallery
1990 Subaru Legacy Wagon AWD 2.2 5sp
2013 Ram Tradesman C/V
My Webshot Photos]
Joined: Nov 2004
Posts: 117
C
Wrench Fetcher
Wrench Fetcher
C Offline
Joined: Nov 2004
Posts: 117
55 1st series, 261, dual carbs, fenton headers, original hydra-matic, 3.90 gear, 28.5" tires = 12.7 mpg at 55 mph for 197 miles.


cgresham1212
If you don't drive it, why have it?
55 1st Series 3100 5 window
Joined: Feb 2005
Posts: 531
L
Shop Shark
Shop Shark
L Offline
Joined: Feb 2005
Posts: 531
I have to get my odometer fixed then I'll know... but even if I get crap milage I'll STILL be driving my daily driver ol' Bolt!


Larry Bear

55.5 Chevy 3100 Panel
In the Stovebolt Gallery


Joined: Mar 2005
Posts: 49
G
Member
Member
G Offline
Joined: Mar 2005
Posts: 49
6 cyls don't necessarily = economy. If thats an issue buy a Toyota.

Joined: Feb 2005
Posts: 399
S
Cruising in the Passing Lane
Cruising in the Passing Lane
S Offline
Joined: Feb 2005
Posts: 399
I wish I knew, but just got my gas gauge workin on my 54 235, and my odometer says 433,321, if you can read those faded numbers..Who cares, just put gas in it, and drive your bolt,Steve..If my truck don't care, I don't care..First Light, me and my buddy are cruisin..Ya'll have a great weekend and if you aren't wrenchin, you should be drivin..Just me, part of the non-smokin bolters (we are really trying)...IT IS PAINTED..

Joined: Feb 2005
Posts: 399
S
Cruising in the Passing Lane
Cruising in the Passing Lane
S Offline
Joined: Feb 2005
Posts: 399
Oh, by the way..the truck and I are going to the introduction of the new 2006 Harley lineup..and free beer and brats..Could even win another one..Hell, it's just across the road..I know my truck will make it that far, and will probably get VIP parking..I would send some pics, but there might be some wet shirts due to the front coming in from the SW..If Stupid doesn't forget his camera..There could be a front with protruding headlights..Next chapter.stay tuned

Joined: Oct 2001
Posts: 3,458
4
Extreme Gabster
Extreme Gabster
4 Offline
Joined: Oct 2001
Posts: 3,458
I get about 15 with my 261 around town with the stock 4.11 gears. I got about 20 with the 216, before it went to knockin. The Rochester could use a bit of tuning, the thing runs a bit on the rich side. When the milage drops down I know its time to reset the point gaps (I have a dual point distributor).


Paint & Body Shop moderator
A lone amateur built the Ark. A large group of professionals built the Titanic.
Joined: Aug 2001
Posts: 258
F
'Bolter
'Bolter
F Offline
Joined: Aug 2001
Posts: 258
When my '54 3/4 ton was a daily driver, I was getting about 12 mpg city and 14-16 mpg highway.

If I pushed it over 50 MPH for any legnth of time, the fuel mileage went WAY down...

Stock 235, Rochester B, 3-speed, 4.57 rear, 7.50 x 15 tires.

Just drove my '72 C-10 long-box with 250 six, 3-sp, on a long trip (400 miles); kept my foot outta the carb (65mph or less) on the way down, and was surprised to actually get 18 mpg.


Frank McMullen
1941 Chevy dump truck
1949 GMC 100 pick-up
1954 Chevy 3600 pick-up
1955.1 4400 dump truck
1941 De Soto & other MoPars
1928 Model A F**D Special Coupe
Joined: Aug 2004
Posts: 1,067
H
Shop Shark
Shop Shark
H Offline
Joined: Aug 2004
Posts: 1,067
I've got a 235 powered 3/4 ton (1952) with 4.56 gears and I average between 13 and 14 mpg on the highway. Shockingly bad for a tiny little one-barrel carb, but I see everyone else gets around that too. As long as I don't commute in it, it's okay.


52 GMC 3/4 ton pickup
68 Big Block Vette
68 455 Firebird
Joined: Jun 2000
Posts: 2,773
F
'Bolter
'Bolter
F Offline
Joined: Jun 2000
Posts: 2,773
52 3/4 ton, 54 model 235 with M4F cam and one bbl, 4.10 gears, 31" tires with stock racks and ruuning down the highway at 60+. I get about 15 mpg.


Fred
52 3600
69 C-10
Joined: Dec 2002
Posts: 571
S
Shop Shark
Shop Shark
S Offline
Joined: Dec 2002
Posts: 571
Just made a trip to Kansas City from Denver. Got 18 mpg with a 57 235, bigger cam, single 1 bbl Carter YF carb, T5 trans. About 70 mph @ 1900 RPM. My guess is about 15 mpg around town.

Joined: Aug 2004
Posts: 1,067
H
Shop Shark
Shop Shark
H Offline
Joined: Aug 2004
Posts: 1,067
Wow, great cruising rpm. My top speed is about 68 mph and that's around 3500 rpm. Must be the overdrive. What did you use for a bellhousing to mate the T5 to the I-6?


52 GMC 3/4 ton pickup
68 Big Block Vette
68 455 Firebird
Joined: Dec 2002
Posts: 571
S
Shop Shark
Shop Shark
S Offline
Joined: Dec 2002
Posts: 571
I used the original bellhousing from the 216. I also used a flywheel from a 261 and the 12 volt starter that was on the 235. This allowed me to keep the foot starter. Another reason for the low RPM is the rear end gear. I bought the rear from a junk yard. It was marked as a 3.73 out of a 65 1/2 ton. I think the gear is higher than that though. Boy did it come alive at the lower elevation of Kansas City. I think I need to rejet the carb. It runs a little rich at this mile high altitude. HRD, what carb are you using? Know where I can get jets for a Carter YF? I don't know which one I need yet though.

Joined: Aug 2001
Posts: 258
F
'Bolter
'Bolter
F Offline
Joined: Aug 2001
Posts: 258
Anbody compare fuel mileage comparing a properly set-up YF Carter against a Rochester B on the same truck ?


Frank McMullen
1941 Chevy dump truck
1949 GMC 100 pick-up
1954 Chevy 3600 pick-up
1955.1 4400 dump truck
1941 De Soto & other MoPars
1928 Model A F**D Special Coupe
Joined: Dec 2002
Posts: 571
S
Shop Shark
Shop Shark
S Offline
Joined: Dec 2002
Posts: 571
Quote
Originally posted by Frank54:
Anbody compare fuel mileage comparing a properly set-up YF Carter against a Rochester B on the same truck ?
Yes Frank. The Rochester got slightly better mileage but I had it jetted leaner. I need to find the right main jet for the YF. It runs a little rich. My guess is once I get the YF right they will be about the same.

Joined: Jan 2001
Posts: 613
Z
Member
Member
Z Offline
Joined: Jan 2001
Posts: 613
so if you want to get decent mileage you should remove the 235 and install a 305?

Joined: Nov 2001
Posts: 275
5
Shop Shark
Shop Shark
5 Offline
Joined: Nov 2001
Posts: 275
Zenish. 305 for a 235. Blasphemy! smile

BTW. My 261 w/od & 3.31 rear end does about 2K rpm at 65. 18 mpg and running rich. Working on the jets this weekend. Currently have all the wheels off to check the balance and front wheel bearings out and back in for repacking.

Going to Goodguys in KC, MO on the 23rd.


1956 Chevy 3100
261/700r4 (formerly 3 speed OD)
In the Stovebolt Gallery
More pix on Photobucket
Joined: Jan 2001
Posts: 613
Z
Member
Member
Z Offline
Joined: Jan 2001
Posts: 613
we have a shop truck that is a 4.3/auto.its surprisingly fast and gets decent mileage.another possible choise.

Joined: Jun 2005
Posts: 887
N
Shop Shark
Shop Shark
N Offline
Joined: Jun 2005
Posts: 887
Does anybody have any gas milage experience with the twin progressive 2 barrel Carter-Webbers Langdon sells? I read another post where someone was getting in the low 20s with the 5 spd o/d, open diff with highway gears, twin two-barrels and HEI.


'51 Chevy 1/2 ton w/'62 261, HEI, offy, fentons, dual carter/webbers, t-5 & 12 bolt posi
Joined: Oct 2003
Posts: 5,152
O
Cruising in the Passing Lane
Cruising in the Passing Lane
O Offline
Joined: Oct 2003
Posts: 5,152
My '72 with a 350 and an automatic with 3.5-something gears gets about one mile per gallon better than my '55 1st with a GMC 270, SM420 and 3.08 gears.

My other V-8 powered truck averages about half what the '72 gets, but it has a 454 and 4.11 gears.


1955 1st GMC Suburban | 1954 GMC 250 trailer puller project | 1954 GMC 250 Hydra-Matic | 1954 Chevy 3100 . 1947 Chevy COE | and more...
It's true. I really don't do anything but browse the Internet looking for trouble...

Moderated by  Phak1, Woogeroo 

Link Copied to Clipboard
Home | FAQ | Gallery | Tech Tips | Events | Features | Search | Hoo-Ya Shop
Powered by UBB.threads™ PHP Forum Software 8.0.0