Lexus and Hyundai currently have 8. Dodge will soon have 9. Now seems Hyundai is upping the ante and developing a 10-speed automatic transmission. Good god, where does this end? Soon cars will be sporting enough gears to make a trucker blush.
Patrick
three is enough .....hate a lot of auto gears
A friend of mine had a 1957 Chev with a 283 V8, loud dual exhaust and a Turboglide transmission. Very different steady tune from the exhaust while the car increased in speed but the engine RPM didn't change that much. Because of its unique operating characteristics, Turboglide did not require large changes in engine RPM even with very large differences in car speed or desired engine output. In fact, accelerating from rest, the engine speed would remain nearly constant(with no movement of the accelerator), even as the vehicle accelerated.
Dick
tly have 8. =A0Dodge will soon have 9. =A0Now
Dick,
Are you speaking of GM's old 2-speed Powerglide?
I had one of those 2-speeds in a 60's Impala I used to own.
Patrick
have 8. Dodge will soon have 9. Now
Nope, the Powerglide was a different transmission. Dick
Thus spake Dickr :
currently have 8. Dodge will soon have 9. Now
By most counts, the Poweglide is the most used transmission in racing. Primarily because of the monsterous number of cars running one in drag racing. I've even seen 2002 F-Birds running one, since by the time you can manage to get to third you're shutting down.
I'll have one in my 351W (408) car. But not a GM product per se'
I suspect a lot of it is marketing. Once you add a third planetary gear set you have all sorts of possible ratios. Now that most transmissions are controlled electronically rather then by simple hydraulic valves, it's almost trivial to add another "gear". I read some years back that in many of these transmissions they often "skipped" one or more of the possible ratios depending on how hard you were accelerating since most of the time you don't need all of them to move things along. It would be interesting to talk to a car makers autobox engineer about this.
I'm sure skipping would have to happen quite often. If you're putting your foot in it, you're not concerned about economy, you want acceleration, so it would make little sense to hit all the gears. But if you're cruising, the trans should then act to keep the engine in it's sweet spot for best MPG. Or so it seems.
Patrick
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