As I looked down to the dash of the Peterbilt 579 that I drive for work and saw the fuel economy gauge it got me to thinking about what most hot rodders get for fuel mileage. Me personally I'm not too concerned with the mileage that my '29 sedan with 472 Caddy engine gets. Although it will get 14 mpg cruising at 65. Bump that up to 75 and it drops to 10-11 mpg. Now the '51 Hudson, stock as a clock 262 flat 6 ,is the fuel economy car. It will get about 20-22 mpg out on the highway and 17-18 around town. Now I know most of us don't build them with fuel economy in mind but I don't mind the bonus of not breaking the bank for fuel. Sent from my A520L using The H.A.M.B. mobile app
I dump about $45 worth of 93 octane in my '59 Ford a week... add another $20 if I toss in an octane booster. I'm tracking my MPG this week, the last time I did I was getting around 10 MPG. I've had my foot out of it a bit and drove normal for a few days, be happy if it hit 12.
depends if you do long distance or stay close to home, or 1/4 mile at a time. with some planning & engineering can get some good mileage out of a pretty wild ride.
52 Ford with a 52 Merc flathead, stock except for Iffy 400 heads, overdrive, 3.90 gears. 18-19mpg mostly highway running ~65. Motor needs to come apart because one cylinder is real low on compression. Probably get better economy if it was sealed better.
I'm guessing the gears in your 472 powered sedan must be kinda low. I had one in its factory location- 68 sedan deville- that got at least as good of mileage. I think it had 2.73 gears but assume it would roll across the scale at 2.5 to 3 times as heavy as a 29? Best mileage I understand is around the engines peak torque which is pretty low in that one. Sent from my iPhone using The H.A.M.B. mobile app
8ba Flathead 37 coupe running two 94's and highway gears. 16-18 on four lane. My 34 truck 59a flathead with dual strombergs lower gearing. Running 10mpg at a max of 60-65 mpg. ..
Checking fuel mileage is probably the easiest method to determine if a stock or stockish engine is properly tuned, even if economy isn't important. If fuel mileage isn't what the engine and drivetrain is capable of, you ain't done tuning. Mostly, best performance always equals best mileage, at least if you can keep your foot out of it. When the ignition timing curve isn't optimized, carburetor air fuel mixture, jetting, power valve etc out of tune, weak spark, then efficiency will suffer. Slightly rich air/fuel mixture is better than going too lean, but it does waste $$, fouls plugs, and if extreme washes out rings and dilutes engine oil.
3.23 rear gears. At 70 mph its turning 2600 rpm. Holley spreadbore 650 Double pumper carb. The car runs excellent except maybe a hair fat on fuel. I think if I had the 2.73 rear it would drastically improve. Our old '47 Hudson with FE390 got 9 mpg when we first bought it. 3.08 rear. After a good tune and fixing some ignition issues it would average 16. Sent from my A520L using The H.A.M.B. mobile app
283 power pac, dual quads, carter afb's, 400cfm. with the 3.73 gears, 31"rear tires at 60mph and at 2300rpm I get 16.4 mpg. Good enough for me.
21+ mpg @ 75mph on I-25. 351 Ford crate motor, AOD, 3.70 rear. Repeatable over and over. 14-15mpg in town.
My '37 Chevy coupe has a 1961 235 engine, 3.73 rear axle and a B-W overdrive in the torque tube. On a trip to Rapid City, S.D. and a bit into Wyoming & back, a round trip of about 3400 miles, mostly on I-90 at 70+mph, I averaged 22.8 mpg. Around town, without the OD, I get around 17-18 mpg.
don't care , as the D/D's and play toys do not make me money but get me to work or out , on the big truck yes milage is a important thing as it cuts into the bottom line of my profits .
My Falcon gets 32mpg with the current engine, but is altitude sensitive. The new engine is going in soon. It has EFI and full digital engine management. That will automatically compensate for altitude. It is way cooler than a Honda. Poor mileage is often a combination of improperly matched parts and poor tuning , rather than anything else. I weld O2 sensor bungs into everything I tune. I have doubled the MPG on several engines that I have tuned. There are only four places that the fuel can go: power, heat, leaks, or out the exhaust. Wasting fuel due to improperly matched parts and/or poor tuning is not a badge of honor. It is just throwing away money.
17/18 around town, 20/22 on trips. 230 flathead six, dual singles, 4.11 rear end. On the highway I run about 3200 rpm (63 mph on the GPS). Will run to 70 but stock brakes feel better at slower cruise.
In '90 I think it was I drove my '32 coupe with a 6-71 blown/two 600 Holley 350 4 spd, to OKC with two friends. One guy had a '31 Chevy coupe with an LT1 that he had put a L79 cam in and he changed the 780 Holley to a 600. The other guy had a '31 Tudor with a TR-1 tunnel ram with two 600 Holleys on a 350. The surprise was on them- they thought I'd always be holding them up stopping for gas but all three of us averaged 17-17.5 MPG on the road running 70 MPH. 3.36 gears, 31" tall tires and a well tuned combination gave the best of both worlds.
My 38 gets about 10 MPG. It has two Stromberg 48's, 4:40 gears, 950 rear tires a melling cam, Sharp heads, Fenton headers and Johnson adjustable lifters. I have a 39 trans with Zepher gears. I have never had the interest in pushing the cluster out on the ground...so I don't rod it!
....but I'm hoping to get 20 with my new Corvair. (still putting stuff back on the motor that the PO removed)
However my shoebox gets 13.7 around town and two laners up to about 60 mph in 5th, on four laners at 80 mph in 6th and its 14.7..Can just make about four hours then time to fill up but I have to stop to pee at 2 hours!!
I drove my 51 merc back from the stray cat 500 at 70 to 75 miles an hour with the air on all the way. It's got a 350 350 with 273 gears. I got 22.8 miles per gallon. Got a quadrojet that I've had apart several times. Can't beat them for gas mileage. Went 205 miles on 9 gallon of gas.
My Roadster has 6/ Stromberg 97's 49 olds engine with 10.5 comp flowed 55 heads and an old Isky full revmaster cam. It has 31.5" rear tires and I usually run a 4/11 gear in the quickchange , over the whole year I get 12.5 mpg. Some days it is about 4 and others 18 , just the fun factor varies! Gary
My Model A w/322 Buick (avatar) th350 tranny and a 3.08 rear got 18.4 mpg the last time I check, happy with that.
'47 chevy coupe, 216 babbitt 6-cyl, t5, 3.08 rear, 28" tire, two one barrel Rochester carbs, electronic distributor, 22 MPG highway, no idea what it gets in town, but it is smiles per miles not miles per gallon.
The Jalopy Journal
