jayvee53

Hello all. A couple of questions baked into one post. So...I know miles per gallon should not be a concern on a 442 and you don't own one for good gas mileage..... but what is a reasonable expectation for a 69 442 with the original 400 and four speed running 3.42 gears? Am I correct in believing the 3.42 gears will offer pretty reasonable highway manners? If I decide to go ahead with the purchase of this car, it's going to have to serve as my primary driver for about 6 months of the year so mileage and highway speed performance would be important to me. Thanks in advance for your input!

don71

About 10mpg. Maybe less, maybe more.

BSiegPaint

I used my old '70 W-30 with 3.91 gears as a daily driver through college and beyond and kept my mileage log - I averaged 10-12 mpg city or highway. My old '68 442 with 3.08 gears got around 15. If it's the right car you want to keep, a few months of higher gasoline bills won't mean much in the long run. If highway mileage is really important, switch rear gears or switch the transmission to an aftermarket 5-speed.

OLDSter Ralph

I would guess 10-13 mpg. Highway speeds and highway distance are a factor. Maybe 13 mpg at 60 MPH, 8-10 mpg at 80 MPH.

jayvee53

Thanks everyone! It's true that "there's no free lunch"....the fun of driving a car like a 442 is going to cost a little bit in the way of fuel. A five speed with overdrive would be sweet though! Probably not cost effective, but a pleasure to drive. Thanks again!

Kyle's77cutlass

If we buy these cars, we dont buy them for fuel mileage!! lol

matt69olds

My 69 with a fuel injected 455 (Holley Sniper) Edelbrock heads, 3.73 gears, TH400 with a Gear Vendor will knock down 17-18 mpg on the interstate. It actually did just a little better with the Q-Jet. Obviously, the engine is well tuned, it took a lots of trial and error and experimentation with the Q-Jet to get it to that point. I set the EFI to the same cruise AFR and timing that worked with the Q-Jet, there may be some room for tweaking and small improvements.

I really think that a well tuned 455 with 3.08, maybe 3.42 gears should be able to get 14-15mpg highway fairly easy. I have no idea how much power it takes to propel a 3800 pound car on the interstate, let’s say for this discussion around 100hp. How hard would a 455 have to work to make a 100hp? And how much fuel would it take to make that 100hp? Keep the vacuum advance functional, keep leaning out the primary side of the carb until you get a lean miss at cruising speed, then fatten up the carb just a little. Make sure the alignment is spot on, tires inflated correctly, etc

61Bat

Its all relative.My 69 GTO with a blown 427 Chevy and Tremec 5 speed with 411 gears would get 2 to 3 mpg (headwind or tailwind) on Methanol. My 61 88 gets 11-12 mpg on 87 octane and i couldn't be happier.

oldcutlass

On a side note what are you going to do about insurance. All classic car insurance companies will not insure daily driver cars.

67OAI

My 1967 W-30 car would get 18 mpg at cruise on the highway when new; it had 3.55 gear from the factory. Town driving nowhere near that.

oldcutlass

No it didn't.

aliensatemybuick

Not sure the “no it didn’t” was in response to 67OAI’s mileage claim, but I took my old 65 Starfire convertible to an Olds show in Meriden CT some years back (I’m in central NJ) and ended up getting 17 or 18 mpg. I filled the car up just before the trip and again just after. I had never filled it up before that (never liking to do that with occasional use cars, esp with a typically short driving radius). Anyway I recall worrying that filling it up had messed up the float or fuel gauge after the needle barely budged for whole 100 mile or so ride up (even knowing what I do of fuel gagues of that era). On the way back the gauge did start to go down, and upon filling it up I discovered just how good the highway miles were on a stock 37 year old (at that time)‘65 Starfire vert with a 3.23 rear and 4 speed m121 Muncie (so no overdrive). So I wouldn’t be surprised by an A-body getting something similar.

VC455

I think that's in range. My stock 455 Vista Cruiser with 2.56 gears and T-400 trans got 15 mpg at a steady 65 mph without any carb tuning.

Toocool

I drive my 67 Vista Cruiser a lot, 330 ci ultra High Compression 4 barrel, Turbo 400, 3.08 rear. It regularly gets 14-15 miles per gallon. I drove it from Nashville to Myrtle Beach a few weeks ago and got 16-17 miles per gallon. Pretty happy with that.

BangScreech4-4-2

OP is dealing with a G-block 400 rather than a 455, not that it'll make all that much difference in terms of fuel economy.

Seff

350/350 combo in a '72 Supreme, with a 2.56 rear gave me a combined mileage of 21 MPG.

rcorrigan5

My '68 4-4-2 convertible with a 3.08 anti-spin differential and my '69 4-4-2 convertible with a 3.23 anti-spin differential (both all stock with THM 400 transmissions) get right around 12mpg, sometimes a little over, sometimes a little under.

Randy C.

jayvee53

OP here...Thanks everybody, just wanted to advise I'm still reading the responses. Thanks again. John

Koda

My 67 442 is not drivable for very far. My 72 chevy can get 20, best possible, on highway, with a 350/th350 2.73. A bigger engine and lower gears would pull that down. I would say highway best 16, probably more like 14, and in town 11.

1robert

My 67 442 with an automatic and 3;90 gears gets 13 highway.

pizza442

Today's fuel makes a bit of diff, too. Especially w/additives and ethanol.

72455

My 72 Supreme with a 455, TH400 and 3.08 gears averages about 12-13 mpg if I stay out of the gas...and that's with a .030 bore and W30 cam. Oh, and that was with the 670 Street Avenger. I just swapped that out for a 770 and haven't checked how it does since the swap...will post when I know more.