I’ll add to missleman’s comments- we don’t need as many speeds as we have on bicycles today, either. With the 27 that are common today there’s a lot of overlap. Of course I might think differently if I were younger, in better shape or lived in hilly country. But it was young bike messengers who broght back the trendy single speed.
The big push on 6-7-8 speed automatics is mpgs. The big increase in CAFE requirements means everything is being pushed to the max.
Jeep’s having trouble with their 8 speed, keeping the new Cherokee off the market.
On my go kart when I was a kid, I wanted to make it go faster so I started changing pulleys. Smaller one on drive, bigger one on engine. I made quite a few trips to the farm store buying different sized pulleys until I found a reasonable combination that allowed me to start from a stop and still get some speed. I learned a lot about gearing from that.
You are right @mayday, we don’t need as many gears as a bike. But, with the mileage requirements we essentially get just that with a cvt. that’s computer controlled and optimized for efficiency. It’s a combination that cannot be duplicated by the standard auto. Unfortunately, gears are stronger then belts, so unless there is some dramatic design change, you don’t see them on too many vehicles that really have to work for a living.
Btw, just like a car, the fewer the gears on a bike, the fewer hills you can encounter or the better shape your legs need be in.
I do think that the PowerGlide 2 speed transmission had problems in mountainous regions. I remember reading an article back in the late 1950s in an automotive magazine that showed how to replace a 2 speed PowerGlide with the GM 4 speed Hydramatic. The author of the article was dissatisfied with the performance of his 265 V-8 Chevrolet wagon equipped with PowerGlide in mountain country. He was able to swap in the transmission because the GM Hydramatic was used with that same V-8 engine in the Chevrolet pickup trucks. I had a colleague back in 1961 who bought a new Chevrolet station wagon. He made frequent trips to the mountainous areas of Colorado. The dealer advised him to go with the manual transmission for this kind of driving which he did.
The Chrysler PowerFlyte which was introduced in mid 1953 and was available in all Chrysler products in 1954 was also a 2 speed unit. In 1957, Chrysler began phasing in the TorqueFlyte which was a 3 speed automatic. By 1961, it became the only automatic for the Chrysler line.
Top fuel dragsters don’t have a transmission, just a clutch that welds itself together during the run and sits on a workbench smoldering for a half hour afterwards.
I’ll never forget an experience I had in the late '90s. I had a '94 “Twin Cam” 16 valve Saturn sedan with the 5-speed manual trans. It went over the hill and dale in Pittsburgh very briskly and gracefully. A friend bought an identical model with the 4-speed auto trans. I drove it through an area called “Sunset Hills” and it was a dog!
I mentioned this before but now is as good a topic to mention it again as any. A sailing buddy received a “gift” if you will from his wife’s uncle, of a Jaguar sedan that had a motor fire. Having his own personal garage and having rebuilt cars for years, his wife asked him to rebuild the motor and “make it more reliable”. Realizing there was little you could do to make that year Jag more reliable, he replaced the motor with a Chevy 6 cylinder and installed a 2 speed power glide. It is reliable. But now, he takes his Sunday drives in it; alone. His wife wants no part of it any more. I must say, one ride in it was enough for me too.
So, as a guy too young to be acquainted with the “powerglide” back in the day: is it anything like having a hydrostatic drive, a la zero-turn lawnmower?
I always liked the packaging benefits of hydraulics–who cares about engine orientation: heck add a second engine in-line if you feel like it! And then there’s fun stuff like differential thrust, etc–exactly HOW bad are hydraulic drive losses, and could they ever make up for money/weight saved by deleting the tranny?
Years ago I learned about electric motors being able to produce full rated torque from a standstill, while internal combustion motors can only produce that output at high RPM.
We were on a ski chairlift at Glen Ellen (now Sugarbush) in Vermont. We had just got on the lift 20 seconds earlier.
The electric motor stopped working, so the lift operators resorted to the “backup” engine, which was a 6-cyl Ford engine with a manual clutch.
It took them numerous attempts of revving engine up to very high RPMs and slowly sliping the clutch to get the lift moving (at a snail’s pace). The engine kept stalling - forcing them to rev it even higher.
They finally got it going.
Guys, the OP got the answer he/she wanted on the first page.
@Whitey–You are absolutely correct, but we old geezers need to get off the subject to share out of date information with each other.
“I remember reading an article back in the late 1950s in an automotive magazine that showed how to replace a 2 speed PowerGlide with the GM 4 speed Hydramatic. The author of the article was dissatisfied with the performance of his 265 V-8 Chevrolet wagon equipped with PowerGlide in mountain country. He was able to swap in the transmission because the GM Hydramatic was used with that same V-8 engine in the Chevrolet pickup trucks”
Gearing is the great equalizer. Many years ago now I was involved in drag racing, preferring the late 60s, very early 70s street cars. Using gearing, I was able to beat people that were frantically stripping every last bit of weight from their cars while I was running OEM metal. AND I was able to drive the car to the track to compete against the trailer queens. The key was gearing. I wish I could take credit for the idea but someone else came up with the basic plan- two TH400s in series that had 5 forward speeds and could more than handle a seriously blown big block producing >900 hp. No problem in my puny 600 hp set up 
While you can build powerglides to handle reasonable power, nobody I know kept them after the TH400 became common unless it was for originality.
Some may remember the variable stall transmissions used on some GM cars for only a few years back in the mid 60s and which were controlled by a switch on the throttle linkage; altering the stall from 1800 to 2800 RPM.
The TH400 version was called the ST400 (Super Turbine) and the Power Glide variant was the ST200; available on Olds, Buick, and a few Cadillacs from my hazy memory.
Yeah a Powerglide worked well but not as efficient as a 3, 4, or 5 speed would.
xaml If you don’t know why we need transmissions, you probably shouldn’t be driving. Do you know why we need brakes? Won’t your car slow down or stop if you let up on the gas?
