Pre computer era high mpg cars
 

Curious as to what the top mpg cars were before modern cars went to fuel injection and computers. I've heard some 'stories' about some of these old high mpg cars but never knew anyone who had one.

One example that comes to mind are the mid 70's Plymouth Feather Duster and Dodge Dart Lite with carb'd slant sixes that were advertised around 35-36 mpg highway. Now by todays standards the Duster/Dart are fullsize cars and they could seat up to 6 adults. Not sure if they really got that kind of mpgs but if they did that seems impressive by todays standards for a carb'd engine with no computers at all.

Honda Civic FE trim level, I think they had an EPA rating (old EPA rating) of mid 50's and maybe even low 60's on a few of the years. I think they started the FE trim level in 1975 or 1978 and kept it up until 1983 when Honda made the CRX 1.3L for a single year (1984) then they started building the CRX HF, but they kept the 1.3L engine in the civic 1.3 (no letters to signify the trim level, just 1.3) up until 1987, after that they started in with fuel injection.

Compare Old and New MPG Estimates

regards
Mech

yeah....and they had one of those 100mpg carbs.......

Please reference a piece of sales material or ad that said this.

...another high-milage model of that same era was the Ford Pinto "Pony."

36 in a Duster- that there is funny.

thanks for the link!

probably closer to 28-29 according to Old mech's link.

I got 27+ all day long in a 66 mustang Sprint. 200 ci straight six w/ a single 1 bll and and auto matic 3 speed w/ 2.76 rear end (no a/c)
I think I ran a F70 14 tire which was slightly taller then the stock size.

I drove it back and forth to college (180 miles each way) so even back then, mileage was important to me.

I hooked up a cruise control and found a led guage that read mpg etc. I had to tell it how many gallons I put in each fill up to keep it accurate. It was really pretty cool. Like the precurser to the scangauge.

I also ran clifford headers - a 3-2-1 desgin. Ended up with the headers collecting into a single 2" pipe and a single in/dual out muffler. I ran GT tips in the pack.
Had to be the coolest sounding 6 banger in town!:cool:

Agreed.

In high school I had a '74 Dart (not the lite model) and the best I got was 17-18 mpg on the freeway. That had the 225 slant six, auto trans, low gear rear and the carb needed rebuilding but still worked. Yes, I did sometimes keep track of mileage even as a teenager lol.

Here is a mileage chart I just found from another site on some older cars. Not sure how accurate it is:

Year Manufacturer Model Engine Disp Trans City Highway
1981 DODGE OMNI 4 M4 30 50
1981 PLYMOUTH HORIZON 4 M4 30 50
1981 DODGE 024/DE TOMASO 4 M4 30 50
1981 PLYMOUTH TC3/TURISMO 4 M4 30 50
1981 FORD ESCORT 4 1.6 M4 28 44
1981 LINCOLN-MERCURY LYNX 4 1.6 M4 28 44
1981 FORD ESCORT WAGON 4 1.6 M4 27 42
1981 LINCOLN-MERCURY LYNX WAGON 4 1.6 M4 27 42
1981 HONDA CIVIC 4 1.3 M4 32 40
1981 HONDA CIVIC 4 1.3 M5 31 41
1981 HONDA CIVIC 4 1.5 M5 32 42
1981 HONDA CIVIC WAGON 4 1.5 M5 30 40
1981 ISUZU I-MARK 4 M5 27 40
1981 ISUZU I-MARK 4 M4 41 51
1981 ISUZU I-MARK 4 M5 37 49
1981 DATSUN 210 4 M5 31 44
1981 DATSUN 210 WAGON 4 M5 31 44
1981 B11 WAGON 310 4 M4 30 41
1981 B11 WAGON 310 4 M5 28 40
1981 B11 WAGON 510 4 M5 29 40
1981 RENAULT LE CAR 4 1.4 M4 29 40
1981 DODGE COLT 4 M4 34 45
1981 DODGE COLT 4 D4 32 41
1981 PLYMOUTH CHAMP 4 M4 34 45
1981 PLYMOUTH CHAMP 4 D4 32 41
1981 DODGE COLT 4 D4 31 41
1981 PLYMOUTH CHAMP 4 D4 31 41
1981 MAZDA GLC 4 1.5 M4 35 43
1981 MAZDA GLC 4 1.5 M5 35 45
1981 MAZDA GLC WAGON 4 1.5 M4 31 41
1981 MAZDA GLC WAGON 4 1.5 M5 31 43
1981 TOYOTA STARLET 4 M5 36 50
1981 TOYOTA COROLLA TERCEL 4 M4 36 48
1981 TOYOTA COROLLA TERCEL 4 M5 33 45
1981 VOLKSWAGEN RABBIT 4 M4 28 42
1981 VOLKSWAGEN RABBIT 4 M5 25 40
1981 VOLKSWAGEN SCIROCCO 4 M5 25 40
1981 VOLKSWAGEN JETTA 4 M5 25 40
1981 VOLKSWAGEN RABBIT 4 M4 40 54
1981 VOLKSWAGEN RABBIT 4 M5 38 56
1981 VOLKSWAGEN JETTA 4 M5 41 57
1981 VOLKSWAGEN DASHER 4 M4 36 48
1981 VOLKSWAGEN DASHER WAGON 4 M4 36 48
1981 DATSUN PICKUP 2WD 4 M4 37 47
1981 DATSUN PICKUP 2WD 4 M5 38 51
1981 AUDI 4000 4 M5 26 41
1981 SUBARU SUBARU 4 1.6 M4 32 43
1981 SUBARU SUBARU 4 1.6 M5 32 44
1981 SUBARU SUBARU 4 1.8 M5 28 40
1980 HONDA CIVIC 4 1.5 M4 32 41
1980 HONDA CIVIC 4 1.5 M5 32 45
1980 HONDA CIVIC 4 1.5 M4 32 41
1980 HONDA CIVIC 4 1.5 M5 32 45
1980 DATSUN 210 4 M5 29 41
1980 DATSUN 210 WAGON 4 M5 29 41
1980 DATSUN 310 4 M5 29 41
1980 DATSUN 510 4 M5 30 42
1980 DODGE COLT 4 D4 31 43
1980 PLYMOUTH CHAMP 4 D4 31 43
1980 DODGE COLT 4 D4 31 41
1980 PLYMOUTH ARROW 4 M5 27 40
1980 PLYMOUTH CHAMP 4 D4 31 41
1980 MAZDA GLC 4 1.4 M5 30 42
1980 MAZDA GLC WAGON 4 1.4 M5 30 42
1980 TOYOTA COROLLA TERCEL 4 M4 30 41
1980 TOYOTA COROLLA TERCEL 4 M5 30 42
1980 VOLKSWAGEN RABBIT 4 M4 40 52
1980 VOLKSWAGEN RABBIT 4 M5 42 56
1980 VOLKSWAGEN DASHER 4 M4 36 49
1980 VOLKSWAGEN DASHER WAGON 4 M4 36 49
1980 VOLKSWAGEN RABBIT 4 M5 26 40
1980 VOLKSWAGEN SCIROCCO 4 M5 26 40
1980 VOLKSWAGEN JETTA 4 M5 26 40
1980 DATSUN PICKUP 2WD 4 M4 39 48
1980 CHEVROLET LUV PICKUP 2WD 4 M5 40 53
1979 FORD FIESTA 4 1.6 M4 26 40
1979 HONDA CIVIC 4 1.5 M5 28 41
1979 DATSUN 210 4 M5 27 41
1979 DATSUN 310 4 M5 27 40
1979 DODGE COLT HATCH 4 D4 32 43
1979 DODGE COLT HATCH 4 M4 32 42
1979 MIRADA CHAMP 4 D4 32 43
1979 MIRADA CHAMP 4 M4 32 42
1979 DODGE COLT HATCH 4 D4 30 42
1979 MIRADA CHAMP 4 D4 30 42
1979 MAZDA GLC 4 M4 30 40
1979 MAZDA GLC 4 M5 30 42
1979 MAZDA GLC WAGON 4 M5 29 41
1979 VOLKSWAGEN RABBIT 4 M4 40 50
1979 VOLKSWAGEN RABBIT 4 M5 41 55
1979 VOLKSWAGEN DASHER 4 M4 36 46
1979 VOLKSWAGEN DASHER WAGON 4 M4 36 46
1979 VOLKSWAGEN RABBIT 4 M5 24 42
1979 VOLKSWAGEN SCIROCCO 4 M5 25 41
1978 FORD FIESTA 4 1.6 30 43
1978 CIVIC CIVIC 4 34 43
1978 ACCORD ACCORD 4 35 45
1978 CIVIC CIVIC 4 33 41
1978 ACCORD ACCORD 4 31 42
1978 DATSUN B-210 4 1.4 29 40

From my own experience, '84 Honda CRX (carbed) would average 44 mpg the way I drove it. Austin-Healy Sprite would probably do in mid-30s. And had an early-70s Mazda RX3 that would do in the 30s cruising on the freeways, but town mpg was closer to single digits.

The killer on small cars getting better mpg was that most trips were too short for mpg gains to really be seen. Not that folks didn't . . but a well-tuned decent full-size American car was close enough. And generally a lot more reliable (and easier to fix; overall economy being more important than just mpg). This changed by the mid-1980's as so many Americans had volunteered to be the beta testers for the Japs. I wouldn't have considered an econo car until then (and didn't) as they also were lousy on the highway. A 1985 Accord is what I'd consider the first pre-EFI econo car worthy of purchasing new (good enough to be a road car, reliable enough to be a commuter, and well-made so that it wasn't junk in seven years).

I also had an I6-200 Ford. No A/C, auto and black vinyl. In a '71 Maverick. In Texas . Not a day goes by that I miss it.

funny you should pull up the 1984 honda crx
that little sucker had a better power ratio to weight than some exotics!
I seem to remember it being compared to a Ferrari in that regard...but dont quote me.

my post on a ford mustang site asking about possible mpg on a 66:

I had a 66 Mustang w/ 200 ci w/ auto 3speed w/ 2.76 (not use the EXACT ratio but it was the 'highway option') and no A/C.
I was in college driving from Dallas to Texas A&M back in the late 70's.
I did the following and got 27mpg on the road.
(not all these were done at the time to get better mpg, but the result was better mpg)
1. At 100k got the head reworked. what a difference!
2. Installed Clifford header. Mounted the 'T' divider to the headers w/ hex bolts to keep it from rattling.
3, Installed a 2" singe pipe from the headers to a 1 in 2 out muffler with 1 3/4 out pipe into gt tips (and a 1 3/4 dual set up to start...why too much for the small cubic inch displacement)
the leaner you run the engine the better mpg.
4. Ran F70 series 14 radial tires. they were slightly larger than stock.
5. Installed a cruise control. Had to change over to a 67/68 gas pedal setup the had a horizontal pull instaed of the 66 vertical pull.
6. Installed a cool little mpg led device that I found at jc withney. had a magnet on the drive shaft to count revolutions anf a flow meter on the gas line. it was usually accurate to about 95%. I always had to imput the fillup.
7. Rear addco sway bay (best 60 buck I have ever spent on any car.
8. Nylon bushings on all the end links
9 lowered front end 1" and set to shelby specs.
10. installed rear air shocks to level the the ride (NOT TO JACK UP THE CAR!!!!!) also set each shock on it's on air line.
11. moved battery to trunk

THe key to better mileage (given a well running engine) is two things
1. Adjust the nut behind the wheel. (hint....the driver) useing a gauge to constantly measure mpg is like plang a vedio game. Just measuring at fillup is past tense and pasive. You need to stay on it every minute.
2. lower rpms. the lower the rpm at cruise, the better mpg. one poster suggested a tranny w/ o/d. this is an EXCELLENT idea. also go up a size or two on the tire (dont go up on the rim)
3. warmer engines burning warm air get better mpg. change out the thermostat to a hotter one. if you aren't driving very far....your not going to get better mileage regardless what you do!

thoughts on tire sizes.
1. the bigger the rim, the farther out you move the moving mass. Moving mass is at 4 times the static weight. so adding 4lb is like adding 12lbs to the suspension parts. THe spindle on the 4 lug six is soooo small it really has a hard time with the additional weight of a stock steel belt radial tire
2. there is plenty of room for taller tires.
3. taller tires will make it slower of the line. (but who cares if you are really wanting better mpg??) this is where an o/d tranny is a plus!

Back in the day I combined and sorted all of the EPA pre-adjustment fuel economy data for ****s and giggles. All of this is on the exact same test or almost the exact same test w/o adjusting for anything. As it turns out, the most fuel efficient no FI car was an 86 carb'ed Chevy Sprint ER, which was a suzuki (just like the metro/firefly).

I think my best non-FI car for mileage was my 1986 Accord. Automatic, but at least it had an overdrive. The mid '80s were a mish-mash for car makers, some went to FI, some stayed with carbs, some had overdrives/5 speeds sooner than others etc. Even in the performance world (for domestics anyway) it was all over the map. My '86 Corvette is the first year for aluminum cylinder heads, first year for tuned port injection, and a bunch of other stuff that was cutting edge for the day, but it only made 230 hp lol! The only really impressive domestic performance car was the Grand National - gotta love turbo power. And yes Fox body Mustangs were coming into their own, with 1986 being the first year for speed density FI, a big rear diff, proper 5 speed etc, but it all just goes to show that mid '80s were all over the place when it came to automotive designs. I make no claim to know what the most fuel efficient non-FI/computerized car is, but if I was going to start looking for it I would think it's going to be mid to late '80s somewhere. And it probably came from Japan. My buddy had a '70s "Hang Ten" Duster back in the '90s, and yeah, that sure wouldn't be the direction I would be looking in!

(Austin) Metro HLE 1.0 claimed 82 MPG (imp) in 1982.

It was only a 4 speed too, and had OHV and a carb.

Gearing was ~19 MPH / 1000 in top, top wack was 82 if you were lucky, 0-60 in 18 seconds - you were more likely to run out of road than speed.

Do you know if the British Ford Escorts back in the day got good fuel mileage? Aside from the economy aspects, I really like the looks of them.

Do you mean the FWD or RWD Scrotes ?

This rwd version is what I'm curious about:

File:Ford Escort Mk I 4 door ca 1970.JPG - Wikipedia, the free encyclopedia

There is a road test of the Mk2 1.1 Popular (same mechanicals as the one in your pic but more square body) here :

Ford Escort 1100 Popular Mk2 & Toyota 1000 Twin Road Test 1975 (1) | Flickr - Photo Sharing!

And a test featuring a Mk1 1.3 Estate (aka Wagon) against 2 other cars here.

Citroen Ami Super - Ford Escort 1300 Estate & Renault 6 TL Group Road Test 1974 (1) | Flickr - Photo Sharing!

They don't seem to give much away but in the test it claims 28 MPG (imp.) for the 1.3 and about 29 for the 1.1. Fords of this era had auto-chokes which were notoriously unreliable which would affect MPG and engine life.

Ford went on to make these RWD live axle ancient things well after the VW Golf, Renault 5 and FIAT 127/128 had come along.

There are loads of other tests there too.

I owned a '73 Duster - not the "Feather" duster but it had a 225 /6 with an RV cam that the previous owner had installed "for more bottom end", he said. It had a 3 speed auto and cruised at 30mpg any time I was on the highway - seriously not bad for a vehicle that size/era.

Also had an 81 Escort (4 speed manual) and an 81 Plymouth Champ (4 speed manual, but with a 2-range overdrive) - both returned 45+ mpg on highway trips, I didn't spend much effort calculating mpg around town. I didn't spend much effort calculating mpg at all, really, but when the gas gauge broke on the Escort I compensated by watching the odometer, 450 miles meant I was close to empty and needed to put another 10-12 gallons in.

For a car of that size to pull that kind of hwy mpg well before computerization and fuel injection became common is saying something imo :thumbup:

Compare Old and New MPG Estimates

Sentra Diesel, original EPA 48 combined.

regards
Mech

Indeed! I was 22 when I owned it, and that was more than a decade ago - I was interested in fuel efficiency for purely monetary reasons at the time - not as much for curiosity or hobby reasons - so I wasn't paying the strictest attention to what made it efficient. Thinking back, I know it had a 2.xx:1 rear axle ratio, and in general the engine operated at very low speeds all the time, even under heavy throttle kick-downs from 3rd gear into 2nd gear, I don't think it saw the high side of 3000rpm. There was no tachometer, I can only guess at speeds. Idle was very low, and as close to silent as a machine with a carburetor and a nearly open induction system can be - just had that offset "snorkus" thing on a round air filter like most cars of that era.

The car was also quiet on the highway, windows up or down. I haven't been able to find data online for that era's drag coefficient unfortunately but it wouldn't surprise me if it was somewhere in the low 30's despite being rwd and having no attention paid to the underside aero.

Thinking of that era's fuel sippers, dad had an I6-powered 74 Maverick 4door when I was young, and I remember we always took that vehicle on road trips because he said it got much better fuel mileage than the other 3 vehicles we owned (super beetle, pinto, chevy scottsdale pickup I6) - also the most comfortable of the cars.

I do miss my old '74 Dart I had in high school. It was factory gold paint but we spray painted it navy blue in my dads old garage along with my buddy who had a same year Duster. I had many memories in that car even took my first date out in it:eek:

That car was so simple to work on mechanically speaking compared to almost everything else I've ever owned. I could also fit 5 of my buddies in it. I think mine didn't get really good mileage as it had really high miles, wasn't taken care of very well by its previous owners, and the carb was very finnicky and needed a good rebuild which at the time I didn't have the money for.

It would surprise the helloutta me. Probably low 40's Cd; high 30's at best.

Thinking about that "36mpg"- it's probably a typo- 26 sounds reasonable/attainable.

If your talking about the Feather Duster/Dart Lite that indeed was the EPA hwy rating for it. That particular model was available for the '76 model year only.

I agree 36 mpg sounds ambitious and its likely very few got that but even upper 20s/low 30s is still pretty good on 1970s technology considering many newer and smaller cars aren't rated much better.

New Dart Lite Competes For Compact Economy Crown

Funny that back then this was considered by some to be a compact car lol.

Spirit of 76 Dart Lite — CLUNKBUCKET

Dodge Dart - Wikipedia, the free encyclopedia

Dart Lite

In response to increased interest in fuel economy, Dodge offered the "Dart Lite" fuel economy package which weighed at least 150 lb (68 kg) less than the ordinary Dart Sport.[4] The 225 Slant Six was the only available engine, equipped with an aluminum intake manifold for the first time since 1960 and a specially calibrated carburetor and distributor. Bumper reinforcement brackets were aluminum instead of steel, while the hood and trunk lid bracing and inner panels were also aluminum. The Slant Six engine block had already been modified for reduced weight in 1975; in the middle of 1976 production its crankshaft was changed from forged steel to lighter cast iron. The high-flow exhaust system included a dual-biscuit catalytic converter, a 2¼" headpipe, and the muffler used on V8 models. The Dart Lite was equipped with a 2.94:1 rear axle rather than the customary 3.21:1 ratio when the car was ordered with a three- or four-speed manual transmission. The A833OD overdrive 4-speed manual transmission housing was made of aluminum. Like all other Darts, the Dart Lites with automatic transmission came with a 2.76:1 rear axle as standard equipment.[4] The Dart Lite with manual transmission was rated by the EPA at 36 mpg (6.5 l/100km) in highway driving. The Plymouth version was the Feather Duster.

I can't find a supporting link right now but I remember reading in a car rag years ago that Chrysler made an all aluminum block 225 slant six in the early 1960s. It was short lived and were mainly used for performance/racing. I wonder how much economy one could have squeeked out of something like that if built strictly for economy?

And for the extreme eco Duster/Dart enthusiast how about an electric Duster:

MOPAR fan converts Plymouth Duster to electric

Not trying to sidetrack my own thread but in case anyone cares, here's some supporting info on the aluminum 225 slant six.

Here is a little background and history on the Aluminum Block Slant Six engine

An Exotic Slant Six | Hemmings Motor News

An interesting fact is that a hemi six was made in versions over 300 horsepower (factory) by Chrysler Australia in the 1970s.

Chrysler Hemi-6 Engine - Wikipedia, the free encyclopedia

The Slant Six just possibly had more FE potential than any other motor -- car or pickup -- into the 1980's. Indestructible was the middle name. As one auto engineer put it, convert it to propane and it'd outlast the sun". With that basis any mods (EFI, turbo) are a good match behind that alu-case 833.