When I first started driving in the 90s it seemed like the 4 and 5 speed transmission was the best, modern transmission you could get. They were relatively reliable, and had enough gears to make acceleration, and fuel economy good in my Honda CRX.
Today, I can buy a Honda Odyssey with a 9-speed automatic transmission standard, and 10-speed on the high end model.
**What has changed in transmission engineering, materials science, and technology to allow more gears in the gearbox?**
What are the potential downsides? E.g. is the typical 10-speed as reliable as the old standard 5-speed gearbox?
Edit: To be more clear, this is an ENGINEERING, MATERIALS SCIENCE, and TECHNOLOGY question. I understand the benefits of having more gears for ride quality, and fuel efficiency.
In: Engineering
Some American cars in the 70s had 2 speed transmissions and v8 engines to get enough torque at low revs to allow that to be drivable. Fuel consumption and emissions weren’t really an issue then.
Now we have cars with an infinite number of gears using CVT. driving one of those feels like driving an electric car; no gear changes, and better mileage.
All automatic translations suffer from the same flaw: they can’t read the drivers mind to know what gear to be in in 2 seconds time. Modern transmissions shift faster with computer control rather than the old ones that relied on engine vacuum to trigger a downshift.
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