My 72 C20 402BB gets about 11 MPG down hill , 7 MPG up hill, and around 9MPG everywhere else.

'67 SWB / ZZ4 / 700R4 / 4:10's / 17.7 mpg

'97 BURB / 454 / 4L80E / 4:10's / 11 mpg

'89 P30 24ft Class "C" RV / 350 / TH400 / 11 mpg

'90 Honda Gold Wing / 1500cc / 5 spd / 39-45 mpg

'67 C20, 406/SM420, recently rebuilt M4MC QuadraJet, 4.10 = 8 city, 14 highway.

(before the clutch failed & some former friends of mine shot out ALL the glass)
'69 IH Loadstar 1703, 345/NP435, some Holley crow-sucking 2bbl, 2spd rear end (don't know the ratios) = 3 city 6 highway

WOW, some of these numbers are baaaad. 72 customcamper, 5 mpg!!!! It must haul ass though. It's good to see these different combos and how they effect mileage. I also have a 70 GMC 402/T400, never checked the mileage, but you can watch the gauge drop while driving.

Stock 350 (odometers rolled over many times) --- Th350 -- 3.42 Posi 11-14 mpg

Last summer when I still had 3.07's out back - i pulled 16 mpg

Q-jet could stand to be cleaned up and possibly rebuilt

I can usually pass about 2 gas stations before I have to refuel...;) With a 350/T350/3.73 gear and a medium heavy foot, I can go back & forth to work 5x's a week plus some little erands and it cost's me $20-25..00

Yeah she passes just about everything in town but a gas pump...LOL


Chuck

70 shortstep with a 250 bored .40 over, Clifford intake, Holley 390 4 Barrel, ported head, RV type cam, 9.0 to 1 compression, header into dual exhaust, 3 spd and 3.73's so far I've gotten about 10 mpg. The carb still has a stumble when just speeding up from a steady cruise, so I hope to improve a couple of mpg.

00 Silverado Z71, 5300, 5 speed, 3.73 gears - 17-18 city, 20-21 HWY


'69 C-30 Car Hauler, 396 4bbl, 4 speed, 3.73 gears (weighs 8200 lbs unloaded :whine: ) 6-7 City, Maybe 8 HWY

67 C-30, 292 L6, 4 speed, 514 gears, Don't know but it can't be too good with those gears!! Hoping to get 20+ with the 6.2L Turbo Diesel I am installing!

67 C-50, 366, 4 speed, 2 speed rear, Have no idea on it either. Its not as bad you would think it was though.

Gas in Canada should be $100 / litre any day now ( 1 gallon = 4.5 ltr ) sure glad I sold my Beetle and bought a truck fro a project :confused:

1999 K10 Suburban, 350/4l60e/3.54gears - 14.5mpg
1968 K20 pickup, 350/4 speed/4/57gears - 7mpg
1969 K10 swb pickup, 350/4speed/3.73gears - 20mpg
1972 K10 Suburban - different stages:

When I first got it: worn out targetmaster 350/th350/3.73 - 11mpg
Tranny died: Worn out targetmaster 350/700r4/3.73 - 11mpg
Sick of targetmaster: Built for torque 350/700r4/3.73 - 11mpg

1996 Furd Taurus 3.0/AX4N - 25mpg
1986 Nissan Maxima 3.0/who knows - 33mpg
1990 Geo Metro (daily driver) very worn out 1.0/5speed - 50mpg
Had a 1992 Geo Metro, bought new, 1.0/5speed - 58mpg hwy
1990 Dodge 3/4ton 4wheel drive 5.9td/5speed/3.54 - 23mpg

Those are all that I have tested.

91 2.2L auto honda accord, 22mpg but just put the timing belt on right so hopefully more soon
68 LWB 2WD 1/2ton sbc406 th350 373 275/60/15 8-10 mph

72 gmc 2500, 402bb, 400 tranny, not sure on rear gearing. i get 7 in the city and about 11 on the hwy

How did you attain this mileage?

1968 SWB FLEET, 350 LT1/4L60E, 3:73- 20-22 MPG. I was surprised.

Hey bro, a 5300 is a 5.3L right? I thought after 98 chevy no longer put a 5 speed in anything bigger than a 4.8L. There's the six speed, but not in the trucks :( Just curious. Is it maybe a 4.8L?

The Imperial gallon is 4.5L, but the standard US gallon is 3.785L.

350 w 9:1 compression ratio, can't remember the cam, but I specifically picked it to have low-end tourque, factory intake (from a '77 camaro - all the engine castings were from the same Camaro), bias ply tires (don't know if it has anything to do with it), METICULOUSLY tuned quadrajet, 1977 Camaro HEI, Mobil-1 10w30, Heddman Headers, glasspacks, dual exhaust, everything properly aligned, lubed, adjusted, and one of the most important things, KEEP YER FOOT OUT OF IT!! Never tried it with the tailgate down to see if I could pick up any. At the time, I thought putting the tailgate down for mileage was BS, plus I didn't want to lose my spare or my jack.

I got 19mpg pulling a small flatbet trailer with a Chevy Sprint on it fully loaded with everything I owned.

I have that pickup parked at the moment (dreaming of a full resto), I put that engine into the '72 suburban hoping to pick up a few mpg, but it didn't happen.

I don't know if I forgot anything.

My 71 GMC 350/350th 3:73's out back. Engine has a mild cam, Edelbrock 650, headers and duals (2 1/2 pipes) with glass packs = 18 feet to the gallon. My 85 Monte Carlo SS stock 305/200r4 with duals and glass packs = 18-20 mpg.

I get 15-18 in the silverado 305/700 w 2.73 gears.

Gallons per mile in the 67. :metal:
Actually it's not all that bad. 10-12 actually, with the 350 sm420 and 4.10's

Thanks for correcting me there CE20934. 3.78 litres to the US gallon makes driving my truck seem so much more affordable at 90 + cents per litre. Maybe on road trips I'll pull a parachute just to look cool. At least smokes are still under $10 a pack at some stores in the city, not like the small towns where there $12.00.

$12.00 a pack? I pitched a bit@h when I had to pay $3.25 at a little mom and pop store by my uncle's house. I think anything over $4.00 a pack I would quit...


Chuck

I said that about a dollar a pack, but I quit for good on 3-24-89.

71GMC 3/4 402, 4spd, 3.54 gear 11.5 all the time. Highway, city, loaded, unloaded. That was with a holley 650 dp. Just switched to an Edelbrock 750 so we'll see if that changes anything

00 Jimmy/Envoy 18.6 per the computer. Averaged 22 on a trip up to Banff with a plastic bucket on the roof (for the camping gear).
99 Regal GS (supercharged) 22 around town.
83 Capri 5.0 (yes a F%rd). 4spd, holley, don't know what gear. 17
62 Impala 235, 3 on the tree. Would you beleive only 10.5!!!? Little motor is working real hard to keep up at 70-75.

Had a 97 Cutlass with the 3.1. Around town it was about 23. That car was amazing on the highway. On a trip to Idaho we averaged 34.5. Got rid of it when the intake gaskets started to leak (learned about Dexron the hard way). Froth in the oil made my decision for me. :whine:

When I broke in the cam on my small block runing the engine ont the stand I went through 3 gallons of fuel in about 30 minute....;not good. That was with a 415 hp small block though

98 grandam 3.1 litre......27-30 mpg city 37-40 mpg hiway