Transmission / Overdrive: Fuel economy numbers

[LeoH]

I'm curious why it is the 50s Stude sixes are noted for upper 20s fuel economy, but my 1960 Lark VI with a 3 spd certainly had nowhere near that result. Actually, I may be misunderstanding, but I'm not aware any of the 60s studes had fuel economy that high.
Why was that the case, in general?

[Tom Bredehoft]

My '60 Lark 2 door with OD has gotten as high as 29.2, averages 23.2 mpg. Don't know about any claims.

[Skybolt]

Overdrive is the key. And a very light right foot. Most of my driving with a Flathead six, 1959 Lark, was lucky to see close to 20mpg, more like 18, but I had a lead foot. With standard no O/D it was a waste of time trying to get good fuel economy. A V8 would have got better mpg because it would be pulling the same car but with less effort. When I installed the O/D trans with matching 4.10 diff it got way better than the standard and 3.54. Putting in the OHV six made it even better. Then I put the 4bbl and if I was light or cruising on the freeway it would be better but then again I liked to sink my foot into it and waste gas.
Len.

[LeoH]

Thank you. I was beginning to get the sense that an OD trans was important and mine didn't have one. I had read, at one point or another about how the V8s did have better fuel economy than the 6s, now I understand why. Being a teenager with the '60, a light foot was not a consideration. The 4 door with a bench seat was a positive.

[RadioRoy]

Also be aware that published economy figures were achieved by experts in the field of economy driving with new cars that were tuned within a gnat's ass of being perfect, and are not necessarily what the average person should expect, especially with a car that's 50 or more years old.

[swvalcon]

My dad had a 60 lark vl when i was a teenager with a stick no od. Use to borrow it to go out some weekends and I know it got well into the 20's and thats with a crazy teenager behind the wheel.

[JoeHall]

IIRC, the econo figures I have seen from the 1950s-60s were at 30 mph, 60 mph, and town driving. All of them did best at 30 mph, and dropped quite a bit at 60. I believe a fathead six would be in its element at 30-40 mph.

In the late 1960s, my aunt and uncle used to have a 1959 Lark VI with OD, and used to brag about how many trips it would make to & from the local beer store on a dollars' worth of gas. Of course the route they took max speed woulda been 55, but I doubt they ever exceeded 45.

In the late 1980s, I had a 40,000 mile, 1960 Lark VI with 3-speed, and tried to use it to commute to & from Fort Knox several times per week, about a 175 mile round trip. It was wound up tight at 60-65 mph, and would run hot if pushed at those speeds very long on the interstate. I first re-cored the radiator and that did not help. It had a 3.73 rear end, so I installed a 3.31, and that did not help. At 60-65 the temp gage would continue to climb till it would begin to detonate. If slowed down to 50-55 it would cool down and continue on. However, the engine always started easily and ran smooth as silk, and I believe you coulda stood a nickel on its edge on top of the engine at idle.

I believe the flat six had its heyday on 1930s to 1950s roads, mostly dirt, gravel of one/two lane blacktop. When road speeds increased by the sixties, they began to fall behind. I believe Stude Corp realized this and tried to address the problem with OHV six in 1961, but it had its problems too. The GM 194 & 230 were the ultimate answer in 1965-66, but nobody wanted a "ChevyBaker".

I have never owned another Stude six, and would not care to.

Just my experience.

[swvalcon]

Joe. Thats strange because that 60's a twin to what my dad had. He was a engine builder by trade and it had a new engine in it and who knows what he did to it. But it would run at 65-70 all night long and we could go any where on $2.00-$3.00 of gas which back then would have been about 6-9 gallons.

[LeoH]

I can't say what my mileage was back then, other than I'm sure it wasn't near 30. It was long enough ago, the idea of putting in a tank of gas and measuring the mileage per tank never crossed my mind

I never remember having an overheating problem and I do remember it was a noisy pup on the highway. Anything I'm looking for doesn't need to do more than 60-65, that's pretty much as fast as I drive now. I float up to 70 sometimes and go, 'whoa!' I