I know it's more about power than efficiency with us, but I'm trying to locate some info for someone who's looking for a Merc and trying to build defenses against his wife's protests before she even thinks of them. What kind of MPG are you guys getting, and in what car/motor/carb combo? What kind of mileage would a Merc Flat 8 get? What about a small block v8 (SBC/SBF) in an early 50s Merc or similar sized car? What could be done to maximize MPG from a v8 in a 50s car? I know my 4500 lb 59 BelAir was getting around 13mpg with a gummed up 4bbl carb on a 350/350 on the way to TX. I think it improved to around 15 after I swapped carbs. I've heard early 50 Chevys with 235 I6s get between 18 and 25 mpg depending on tuning, etc. I've never checked mine.
It is all about efficiency when you're talking power. A properly built and tunned performance motor is an efficient one. I knock down somewhere in the neighborhood of 16 to 18 in my '65 C-10 loaded or unloaded. Mixture of hwy and in town. 355 or so cubes, Turbo 400 no lockup no OD 3.08:1 gears. Single 4 etc. Most inline 6s don't do any better it depends on how they are built and if they are running the right gear. My last flatty got 12- 15 in a '46 truck, stock tranny and rear. 3x2 and Offy heads, mallory, and twice pipes. But that was when gas was .27 for ethel. The whole OD thing is a myth for the most part. 8 out of 10 times they end up geared too tall, the motor never runs in its powerband and burns more gas in the process. not to mention what that does to the motor itself. Well there I go back up on my soapbox.
I get called everything but white boy when I mention this but...... My 1400lb bucket gets 30+. 1951 Merc Flatty, 5 speed (overdrive=good!) and a 4:11 geared banjo. Drive like an idiot and it drops but it's decent nonetheless. BTW...my dailey Caprice wagon w/a stock 305 and 4l60 gets 20+ in town!
Granted the motor is on it's last leg...my 62 Tempest's little 195 I-4 is putting in a VERY respectable 28mpg!! It's actually the main reason I chose this tempest over a '62 Falcon and a 1968 Caddy Sedan DeVille I was looking at...the fact that at $3/Gallon, I could still afford to drive it! Granted top speed is about 80 if you REALLY push it (after about 30 minutes of that you're gonna need a quart perhaps), but it still plugs along just fine. She's not the fastest, but she's sure the cheapest and bravest out there, and I'm willing to put money on that! Jarrod aka "Fullmetal" aka "Jar Jar" aka me P.S. Petrol at the time of this posting in Scottsdale AZ (where I go to school) at Hayden and Scottsdale Rd was posted at $2.89/Gallon...let's see those punks give me shit about driving a 4 banger NOW!
I have heard guys running flattys w/ T-5's, dual carbs, 4.11 rear, 6.00 front tires and 7.50 rears getting 30+ mpg. That's awesome...makes you wonder what the hell they are "trying" to do in the car market in the area of fuel economy, especially when we are using 50 - 60 year old technology w/ some improved gearing...and getting almost better results w/out FI. Just thinking about it gives me goose bumps.
Thanks for that info... I was meaning to ask you at Autorama... I've got a hankerin for one of those wagoons.
My 52 Chevy w/ mild 350, Muncie 4-speed, Holley 600, HEI and 2.73 rear gears averages in the high-teens with a combination of city & hiway. I'm running tires that are about 27" tall on the rear, and I do some mild "spirited driving" at least a little bit in each tank of gas. The tall 1st gear in the Muncie and the long-legged rear make it REALLY sluggish off the line, though. Kicking around the idea of going to a 5-speed and deeper gears... 3.70-ish. On the way home from the Roundup, I got 22.9 mpg! I find my mileage is a lot better running 93/premium... such that it is actually cheaper in the long run to do so. If I turn my a/c on, my mileage is probably 2/3 of what was stated above.
Try running more boost. Oh I guess I shoyuld ad that my FE powered '65 galaxie was getting around 12 - 14 when I still had it. 390 4V, Pissy edelbrock cam and a 750 edelbrock carb. C6
55 chevy 350cu, 5speed overdrive, 3:08 gears small wiend blower, 600cfm edelbrock carb, 27" tires highway, 23mpg Carlg
Stock 394 except it's got a 2 barrel and manifold from a 371, in a basically stock '62 Olds 98... 25-28 around town 30+ on the highway Unless I'm headed into the wind or tearin' it up real good. Then of course it drops significantly. Olson
about 17 or so, that's a guess on the low side for my 64 impala wagon, 350, mild cam, dual quads, 3.36 gears and cruising at 70-75.... not to bad for that tank
48 Chevy coupe, 355ci, 700r4, 270 gears, 20mpg on the hiway at 80mph. 40 Chevy 4 dr sedan, 305, 700r4, 270 gears, 18mpg on the hiway at 70mph. 34 dodge modified, blown 225ci, 904, 323 gears, 24 mpg on the hiway at 70mph. 65 Mustang, 200ci, c-4, 300 gears, 16mpg on the hiway at 70 mph. If you look at the top two, this backs up what someone said about the overdrives. I'm not getting that much better mileage with the overdrives. In fact with the 48, if I drive it in 3rd, with the converter locked up, at 70mph, I get the same mileage I do at 80 mph in fourth locked up.
who cares!!! if i was interested in good milage i'rd buy a diesel honda!!!! just so you know ZZ4,350 with a 700R4 in a steel full fendered A, 15mpg round town 25mpg on a run......Oh and gas here is nearly £5 per gal or close to $9 in colonial money!!..........and I can get it to below a mile per gal if I really try hard!
my T (with a rather warmed over T engine) get about 12-15 providing i dont foul the plugs driving around town.
41 Ford cpe, weighs 3700lbs. crate 425 hp 454, 700R4, 3.42 gear, 255/60x15 reat tires. Have pulled a high of 19 mpg on the x-way running 70-75, but it's usually around 17-18 mpg on the highway. In town I tend to be getting into it and it goes down to 12-13 mpg
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