Due to unexpected car problems last week, I had to rent a car for a few days. My rental was a new KIA K5 LX5. Not a bad car and good power. So I looked it up and it has a 8 speed automatic but they claim that it's not an automatic but a computer controlled manual transmission known as a twin clutch. Well it was a smooth as any automatic I ever drove. Of course the articles I read try to scare people into thinking that if you drive it like a conventional automatic, you'll ruin it or some such rubbish because it has no torque converter. So is this new ALLSON TC based on a twin clutch design? That lousy ASTRONIC was jerky in buses and I understand there are some cars that have such a design as well. Why hasn't tranny builder offered a twin clutch design principle like the one in the K5 where it's smooth as a ALLISON B500? To me though an old standard torque converter tranny is best. However, if it's a twin clutch type in a future new car for me ok too as long as I don't have to shift it myself. Here's a funny twist. My car is an '04 MERCURY GRAND MARQUIS with an 8 cylinder engine and 4 speed automatic. While my rental was a '21 KIA K5 with a 4 cylinder and 8 speed automatic.
Less power,, less torque,, more gears are needed to keep the little sewing machine spinning..>>>Dan
Multi-gear transmissions are in pursuit of hyper fuel economy.
The auto manufacturers can no longer ignore the waste at certain rpm compromises that the old 3 or 4 speeds had. The multiple overdrive ratios for keeping the engine sipping as little fuel as possible in a wider variety of road and headwind conditions.
The sort of thinking that went into the heavy truck drivetrain development over 20 years ago is finally being applied to autos, not willingly, mind you, it is all fuel economy regulations driven.
Trucks owners are in it to make money, auto owners are in it to lose money.
Epic difference...
Happy coaching!
Buswarrior
Some GM models have 10 speed transmissions
Last year on my vacation to Dayton, OH, they upgraded my rental car to a CADILLAC XT4. That thing had a 9 speed. Could hardly feel it shift.
Quote from: CrabbyMilton on April 29, 2021, 07:09:29 AM
Last year on my vacation to Dayton, OH, they upgraded my rental car to a CADILLAC XT4. That thing had a 9 speed. Could hardly feel it shift.
Our son has a new Cadillac SUV it is smooth as silk shifting
I had forgotten that EATON had the PROCISION which was a dual clutch type for medium trucks and buses. It was only built for a few years before being discontinued.
I have a 10 speed auto transmission in my 2019 ranger 4x4 with the tiny 4 banger turbo and the truck is awesome . At regular driving with out a heavy load , gives very good mileage . Today I towed a 1300 lb car float and it ran just like normal up until I put a 3000 lb 6.5' x 10' farm dump trailer on it total 4300 lbs . truck ran great up through the gears up to 10th gear until I got to 65mph than most small hills it would only go up to 8th and stay there . Ran fine but it was working. So because of all the gears the truck can do great without a load and ok with a load . great truck
My wife has a 2021 Hyundai Santa Fe ltd calligraphy and it has the same 8 speed double clutch in it and so far it is amazing on power and millage and quiet inside with lots of toys and it drives itself
how things have changed
dave
The new ford powerstokes have a 10 speed auto, very smooth, keeps the engine in the perfect power band
The Allison TC10 transmission was discontinued about a year ago.
Quote from: belfert on April 30, 2021, 07:14:50 AM
The Allison TC10 transmission was discontinued about a year ago.
The TC10 and TC12 Allison were sold to Eaton ,those are good transmissions ,I have a friend that was testing those for bus use in his MCI J models