What is realistic MPG for a daily driven SBC?

First off, happy Thanksgiving to all.

I'm certainly not a trailblazer, but after being held hostage by some dealer-only service related issues with our modern daily drivers I'm thinking of getting an early to mid-60's full-size Chevy to use as my daily driver.

Currently, I drive 90 miles round trip w/ a Honda Fit. What could I expect in terms of a reasonable expectation for a daily driven SBC?

I'm a flathead Ford guy, so I'm not too familuar with SBC's. I do have a large journal '68 327 w/ 492 heads in my garage.

I'd be willing to put some money into the engine and use an EFI set-up and a modern 5 or 6 six speed trans (stick or auto) if that would help me to get more MPG.

I really don't want to go the 6 cly. route, so any thoughts or experience on what I could expect?

Thanks all.

 

dont nix a chevy six they get great mileage. an plenty hop up part out there for them

 

I've done the same, though I went with a Cadillac SDV because of the size of my family. If it is overall costs you are wishing to save, add (or subtract) the savings in payments and insurance.
As to mileage, you want a long stroke engine. The reason is that the fuel you stuff into the cylinder will do the most work with a long stroke engine. So for a Chevy, a 305 is one of the best choices, for economy.
As to what MPG numbers you may achieve, the are too many factors to even guess. But, I am getting 12 everyday, and 14-15 on the highway with my car, which is better than the equivalent choices at my employment (Nissan dealer). The 500 is a long stroke version of the 472.

Cosmo

 

Save money buy a 92-96 Buick Roadmaster wagon for half the price of the same drivetrain in a chev. they are a boat that will deliver mid20's mpg highway and haul ass. real fun car

 

As said already the six does get good gas mileage but as far as using the 327 you have for that it won"t happen unless you go with a stock 327 and a 2-barrel carb. You said you want mileage so really if you want fuel mileage in a full-size Chevy find you an earlier 60s Chevy with the 283 or 327 engine in it or a 68-or early 70s Chevy with the 307 or 305 engine as these were better on gas,not as much power but you can"t have both its either power or gas mileage in a full size heavy car.

 

Depending on how you build it you can expect mid 20s hiway, and probably high teens to low 20s avg. Overdrive is a great idea for the speeds traffic runs at these days. Keep your cam profile conservative with a peak TQ number in the 25-2800RPM range and look to target just below that with gearing at your daily cruising speed. The 327 should be a decent choice and there's generations of different ways to get what you want. I'd suggest a 3X2 for all the reasons you can imagine on a 60s hotrod with the bonus of 2bbl cruising. the biggest factor in your goal will be your right foot so don't expect miracles until you finally settle down with your new car. The rest of the MPG goals will require attention to weight, tire choice (radials), body style, and all of the obvious things you can imagine. The average full size early Chev will run around 3600# give or take a couple hundred and sedans are typically lighter than HTs. Don't rule out a decent tri-5 2dr sedan either. Then there's early PUs if it's for your personal use more than anything else. Light and easy to get, not hard to live with either. Whatever you build don't forget a security system. Sadly that seems to be a much a requirement as gas these days. Good luck...AND BUILD IT HERE! We wanna see what you do.

 

if it's stop and go, expect 12-15, if it's all open highway driving you could get into the low 20s if you really try.

Modern cars do good on gas, old cars do better on depreciation.

 

I would think low 20's would be achievable in a fairly light car, an overdrive trans and conservative driving habits. the 327 might get you there but there are other choices that would make it easier.

Frank

 

A buddy of mine had a stock 350 horse 327 Vette back in the early 70's. It would get 20 on the highway all day long.
A 4 bbl will get the same gas milage as a 2 bbl as long as you keep your foot out of it. Actually the primaries on a Quadrajet are smaller almost any 2 bbl you could run.
Larry T

 

I'm running a 65' 283 with a mild mid-range Crane cam, 3:43 rear end, GM 5 speed, and a 500 Edelbrock in a 27 Ford Roadster Pickup. I average 18 MPH in town & have gotten as high as 22 MPG on the highways at a steady 65 MPH.

 

How about a early Chevy II wagon u could save on weight.

 

64 nova wagon with a stock 305 , 4 barrell and dual exhaust and 200r4 overdrive gets an average 16-18 mpg . solid highway drive the best i've seen is 23 mpg. i've considered going EFI but the thing runs great as is .

 

My 54 gets 18-20 with a 350/400. 650 carb.

 

My car is by no means an "economy car" with its Oddy's built 408 cu.in. (large) small block. But I do drive it alot on the street so I opted for a well built 700R4 overdrive built by Art Carr Performance. Now keep in mind that I am running a large cube, big horsepower and big tire car and I'm getting about 18 mpg with 4.30:1 gears. I think that's pretty damn good all things considered. So with the right combination I think mileage in the mid-20's perhaps more would be within reach. Also, I use to have a bone stock '57 Buick Special Riviera that got 21 mpg.

 

My beatdown '91 Caprice wagon (183,000 miles) gets 23 on the freeway.

 

Never thought of that. I would certainly consider one of those.

I want to clarify, I'm not married to the 327 I have. I just threw that out there. I'd have lots of friends who are into SBC's so tracking the "right" one down shouldn't be an issue.

 

My Nova Wagon weighs 3268 lbs. I don't know about you but I think that's a "Heavy Chevy"

 

I bought a beautiful '94 wagon from the original owner five years ago and put it in storage. My daily driver died about a month ago so I got it out and started driving it. I'm pretty religious about checking mileage. Mine has gotten an honest 26 MPG on the highway but around town I can't get over 12. Of course I can't keep my foot out of it mostly from taking care of the kids in the rice burners. The 92-96 Roadmasters came with the same LT1 350's that went into Corvettes except for cast iron heads. I have no idea what the production numbers were but you don't see too many of them around here. Oh, and I have hauled a 28 roadster pickup cab in the back!

 

Thought about those too... If I'm going to do it, I want to stay away from anything with a CPU unless I add EFI or some type of electronic fuel management or ignition.

Otherwise, I want to be able to fix anything that goes wrong on the car myself.

What drove this was the ignition cylinder went bad on our '03 Honda cylinder. The key was has an imobilierize chip. I literally could change it out in 15 minutes, but once the old one would be disconnected from the CPU, the car wouldn't start again.

So my choice was either fix it & have the car towed to the dealer (major hassle) or have them R&R the ignition switch.

I did negotiate the labor & reprogramming down from $275 to $220 & I supplied the part which I purchased on-line from another Honda dealer.

The on-line switch saved me $60 bucks vs. walking up to the counter for the same part.

Plus, BMW & VW have been doing this for years, but now Ford is even not allowing user access to oil or trans. fluid fills. You have to go to the dealer to put in trans. fluid or motor oil. Really? WTF!

This dumbing down of products is pissing me off like you wouldn't believe and I don't want any part of it.

 

best every day driver that i have that we all can ride it get 14-18 in city and 24-28 mpg on hwy.caddy fleetwood 93-6 all chevy drivetrain

 

don't discount the 5.0 Ford,if your a Ford flathead guy...I have installed the 302/AOD in a 50Ford sedan and a 64 Mercury Meteor...put a 4bbl Holley and accel dist on the 50 and used all the original manif/carb (2bbl) and dist on the Meteor and both cars del'd 20-22 MPG Hwy and 15-17 in town....great combo and you don't have to call the hook to take it into the EFI shop when things need fixed....

 

Another vote for the Chevy 6. Performance goodies can be found, build it for Torque which it has in abundance! Run synthetic oil, and play all your mileage "cards". Esp cam and breathing choices.

 

My Off-Topic ride: 1973 Firebird, 408 small block, 200-4r, 3.70 rear, megasquirt EFI = 18 mpg in mixed driving w/heavy foot. It's pretty good for 330 @the wheels and drives nicely. But having built all that nonsense, the Willys WILL NOT have EFI and overdrive. Yes, you can have good milage for what it is, but you'll never trump the fuel milage of the Honda 4 cyl with a carbed SBC. I love my old small blocks, too bad they can't get 30 mpg and pull 10's at the strip.....

Here's a crazy idea, how about a T-bucket with a 2.3 Ford 4-cyl and a 5 speed out of a Range pick-up? I've wanted to build one of those of years.

 

I have a '63 Chevy II wagon with a I6 194ci, stock gears 350t trans. O'ffy manifold, with a holley 390 carb., I get 19mpg on the hwy, 15hwy around town. Not bad & it's my daily driver. I have a 250ci out of an Impala on the stand for a rebuild this spring. I'm going to get a 200r od trans sooner or later.

 

You have to consider "power to weight" ratios. Yes you would think a 6 cylinder would get better mpg than a V8 because it has 2 less cylinders. However when they are moving the same weight the 8 cylinder has the advantage. As I stated previously, my '67 Nova Wagon scaled in at exactly 3268 lbs. with a big-small block and I'm getting 18 mpg. Whereas "Ricky B" has a similar car and is getting about the same or less mpg. Reason being is that it is harder for that 6 cylinder to move the same weight as an 8 cylinder. Therefore less work and less effort means less wear & tear and less gas to propel the same mass equals better fuel economy. Another case in point, a 1982 Chevy Caprice with a V8 got better gas mileage than the same '82 Caprice with the 4.3 litre-V6.

 

lust about every hop up for the six has an end result of more mpg cant beat that

 

1) Thanks for the wishes, but i feel, in a way, thanksgiving celebrates the murder and displacement of Native Americans, but we won't get into that..............


2) i'm in the same boat as you; i wanted to run a non-computerized SBC for the very exact reasons you are wanting----to be able to fix anything and everything myself. i decided this after having a string of less-than-satisfying results at the dealer service center(s).

Presently, i get about 15-17mpg with a 3800-4000lbs pickup.
305 cid small block completely stock out of 78 malibu
rochester 2G
th-350C (lockup converter)
2.56 rear axle ratio

stock exhaust manifolds, but with true dual exhausts, flowmaster 40s

Before the 305, i used a crate 350 with rochester quadrajet, but the mpg was still 15-17.

Here is my on-going scientific study regarding mpg with a small block if you're interested:
http://forum.73-87chevytrucks.com/smforum/index.php?topic=8474.0


If you're going 65 impala, your weight should be lower and i think that is a key to better mpg. 20 should be do-able with good compression/exhaust/gearing.

 

You want an early to mid-sixties full size car and a small block Chevy for a 90 mile commute in the Garden State? I would find a cherry four door 61-64 Chevy from the Southwest and a 90's full size LT1/4L60E donor car and put the two together. Good power, good mileage, and something to make that commute more fun.

 

I make runs between VT and CT a few times a year. No stop and go just get up to speed and hit the cruise control. My stock l03 5sp 305 '89 firebird has gotten 29mpg before. The 83 with the stock 700r4 LG4 305 and Q-jet has gotton a best of 27.

On mixed highway and surface street use it drops to the high teens/low 20's.

 

I can certainly agree with you wanting to give the big F-U to modern stuff & the dealer gang-bangin' ya get with it . That's why my daily (up until I sold it to get my shoebox project) was an old Volvo Amazon . Cool old-school looks , reliable as a stone and got mid-20's all day long around town . It's not an ass-kickin' v-8 powered monster , but it did the trick for a few years & got a ton of attention . Here she is :





Till the shoebox is done , I'm sportin' the wife's old '91 Jetta (I know , I know ) - but it gets in the 30's MPG around town with 197k on it , so that helps save $$ for my 'box project , so ya gotta do whatcha gotta do ! When the old Ford is roadworthy , it'll be my daily , just as my Volvo was .

Good luck finding something cool ...